Update libchdr (replace libflac with dr_flac)

author: jdgleaver 2021-03-15 15:36:34 +0000
committer: jdgleaver 2021-03-15 15:36:34 +0000
commit: 2ff0b5124f2e17a290121e1eeecf45db1d9e2c85 (patch)
tree: 3cf574af74146252926490c2816d95e34a602a3c /deps/libchdr/src
parent: e3e1b865f7c06f57918b97f7293b5b2959fb7b7d (diff)
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5 files changed, 4058 insertions, 0 deletions
diff --git a/deps/libchdr/src/libchdr_bitstream.c b/deps/libchdr/src/libchdr_bitstream.c
new file mode 100644
index 0000000..c82a67d
--- /dev/null
+++ b/deps/libchdr/src/libchdr_bitstream.c
@@ -0,0 +1,125 @@
+/* license:BSD-3-Clause
+ * copyright-holders:Aaron Giles
+***************************************************************************
+
+    bitstream.c
+
+    Helper classes for reading/writing at the bit level.
+
+***************************************************************************/
+
+#include <stdlib.h>
+#include <libchdr/bitstream.h>
+
+/***************************************************************************
+ *  INLINE FUNCTIONS
+ ***************************************************************************
+ */
+
+int bitstream_overflow(struct bitstream* bitstream) { return ((bitstream->doffset - bitstream->bits / 8) > bitstream->dlength); }
+
+/*-------------------------------------------------
+ *  create_bitstream - constructor
+ *-------------------------------------------------
+ */
+
+struct bitstream* create_bitstream(const void *src, uint32_t srclength)
+{
+	struct bitstream* bitstream = (struct bitstream*)malloc(sizeof(struct bitstream));
+	bitstream->buffer = 0;
+	bitstream->bits = 0;
+	bitstream->read = (const uint8_t*)src;
+	bitstream->doffset = 0;
+	bitstream->dlength = srclength;
+	return bitstream;
+}
+
+
+/*-----------------------------------------------------
+ *  bitstream_peek - fetch the requested number of bits
+ *  but don't advance the input pointer
+ *-----------------------------------------------------
+ */
+
+uint32_t bitstream_peek(struct bitstream* bitstream, int numbits)
+{
+	if (numbits == 0)
+		return 0;
+
+	/* fetch data if we need more */
+	if (numbits > bitstream->bits)
+	{
+		while (bitstream->bits <= 24)
+		{
+			if (bitstream->doffset < bitstream->dlength)
+				bitstream->buffer |= bitstream->read[bitstream->doffset] << (24 - bitstream->bits);
+			bitstream->doffset++;
+			bitstream->bits += 8;
+		}
+	}
+
+	/* return the data */
+	return bitstream->buffer >> (32 - numbits);
+}
+
+
+/*-----------------------------------------------------
+ *  bitstream_remove - advance the input pointer by the
+ *  specified number of bits
+ *-----------------------------------------------------
+ */
+
+void bitstream_remove(struct bitstream* bitstream, int numbits)
+{
+	bitstream->buffer <<= numbits;
+	bitstream->bits -= numbits;
+}
+
+
+/*-----------------------------------------------------
+ *  bitstream_read - fetch the requested number of bits
+ *-----------------------------------------------------
+ */
+
+uint32_t bitstream_read(struct bitstream* bitstream, int numbits)
+{
+	uint32_t result = bitstream_peek(bitstream, numbits);
+	bitstream_remove(bitstream, numbits);
+	return result;
+}
+
+
+/*-------------------------------------------------
+ *  read_offset - return the current read offset
+ *-------------------------------------------------
+ */
+
+uint32_t bitstream_read_offset(struct bitstream* bitstream)
+{
+	uint32_t result = bitstream->doffset;
+	int bits = bitstream->bits;
+	while (bits >= 8)
+	{
+		result--;
+		bits -= 8;
+	}
+	return result;
+}
+
+
+/*-------------------------------------------------
+ *  flush - flush to the nearest byte
+ *-------------------------------------------------
+ */
+
+uint32_t bitstream_flush(struct bitstream* bitstream)
+{
+	while (bitstream->bits >= 8)
+	{
+		bitstream->doffset--;
+		bitstream->bits -= 8;
+	}
+	bitstream->bits = bitstream->buffer = 0;
+	return bitstream->doffset;
+}
+
diff --git a/deps/libchdr/src/libchdr_cdrom.c b/deps/libchdr/src/libchdr_cdrom.c
new file mode 100644
index 0000000..58be015
--- /dev/null
+++ b/deps/libchdr/src/libchdr_cdrom.c
@@ -0,0 +1,415 @@
+/* license:BSD-3-Clause
+ * copyright-holders:Aaron Giles
+***************************************************************************
+
+    cdrom.c
+
+    Generic MAME CD-ROM utilties - build IDE and SCSI CD-ROMs on top of this
+
+****************************************************************************
+
+    IMPORTANT:
+    "physical" block addresses are the actual addresses on the emulated CD.
+    "chd" block addresses are the block addresses in the CHD file.
+    Because we pad each track to a 4-frame boundary, these addressing
+    schemes will differ after track 1!
+
+***************************************************************************/
+#include <assert.h>
+#include <string.h>
+
+#include <libchdr/cdrom.h>
+
+#ifdef WANT_RAW_DATA_SECTOR
+
+/***************************************************************************
+    DEBUGGING
+***************************************************************************/
+
+/** @brief  The verbose. */
+#define VERBOSE (0)
+#if VERBOSE
+
+/**
+ * @def LOG(x) do
+ *
+ * @brief   A macro that defines log.
+ *
+ * @param   x   The void to process.
+ */
+
+#define LOG(x) do { if (VERBOSE) logerror x; } while (0)
+
+/**
+ * @fn  void CLIB_DECL logerror(const char *text, ...) ATTR_PRINTF(1,2);
+ *
+ * @brief   Logerrors the given text.
+ *
+ * @param   text    The text.
+ *
+ * @return  A CLIB_DECL.
+ */
+
+void CLIB_DECL logerror(const char *text, ...) ATTR_PRINTF(1,2);
+#else
+
+/**
+ * @def LOG(x);
+ *
+ * @brief   A macro that defines log.
+ *
+ * @param   x   The void to process.
+ */
+
+#define LOG(x)
+#endif
+
+/***************************************************************************
+    CONSTANTS
+***************************************************************************/
+
+/** @brief  offset within sector. */
+#define SYNC_OFFSET 0x000
+/** @brief  12 bytes. */
+#define SYNC_NUM_BYTES 12
+
+/** @brief  offset within sector. */
+#define MODE_OFFSET 0x00f
+
+/** @brief  offset within sector. */
+#define ECC_P_OFFSET 0x81c
+/** @brief  2 lots of 86. */
+#define ECC_P_NUM_BYTES 86
+/** @brief  24 bytes each. */
+#define ECC_P_COMP 24
+
+/** @brief  The ECC q offset. */
+#define ECC_Q_OFFSET (ECC_P_OFFSET + 2 * ECC_P_NUM_BYTES)
+/** @brief  2 lots of 52. */
+#define ECC_Q_NUM_BYTES 52
+/** @brief  43 bytes each. */
+#define ECC_Q_COMP 43
+
+/**
+ * @brief   -------------------------------------------------
+ *            ECC lookup tables pre-calculated tables for ECC data calcs
+ *          -------------------------------------------------.
+ */
+
+static const uint8_t ecclow[256] =
+{
+	0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x0c, 0x0e, 0x10, 0x12, 0x14, 0x16, 0x18, 0x1a, 0x1c, 0x1e,
+	0x20, 0x22, 0x24, 0x26, 0x28, 0x2a, 0x2c, 0x2e, 0x30, 0x32, 0x34, 0x36, 0x38, 0x3a, 0x3c, 0x3e,
+	0x40, 0x42, 0x44, 0x46, 0x48, 0x4a, 0x4c, 0x4e, 0x50, 0x52, 0x54, 0x56, 0x58, 0x5a, 0x5c, 0x5e,
+	0x60, 0x62, 0x64, 0x66, 0x68, 0x6a, 0x6c, 0x6e, 0x70, 0x72, 0x74, 0x76, 0x78, 0x7a, 0x7c, 0x7e,
+	0x80, 0x82, 0x84, 0x86, 0x88, 0x8a, 0x8c, 0x8e, 0x90, 0x92, 0x94, 0x96, 0x98, 0x9a, 0x9c, 0x9e,
+	0xa0, 0xa2, 0xa4, 0xa6, 0xa8, 0xaa, 0xac, 0xae, 0xb0, 0xb2, 0xb4, 0xb6, 0xb8, 0xba, 0xbc, 0xbe,
+	0xc0, 0xc2, 0xc4, 0xc6, 0xc8, 0xca, 0xcc, 0xce, 0xd0, 0xd2, 0xd4, 0xd6, 0xd8, 0xda, 0xdc, 0xde,
+	0xe0, 0xe2, 0xe4, 0xe6, 0xe8, 0xea, 0xec, 0xee, 0xf0, 0xf2, 0xf4, 0xf6, 0xf8, 0xfa, 0xfc, 0xfe,
+	0x1d, 0x1f, 0x19, 0x1b, 0x15, 0x17, 0x11, 0x13, 0x0d, 0x0f, 0x09, 0x0b, 0x05, 0x07, 0x01, 0x03,
+	0x3d, 0x3f, 0x39, 0x3b, 0x35, 0x37, 0x31, 0x33, 0x2d, 0x2f, 0x29, 0x2b, 0x25, 0x27, 0x21, 0x23,
+	0x5d, 0x5f, 0x59, 0x5b, 0x55, 0x57, 0x51, 0x53, 0x4d, 0x4f, 0x49, 0x4b, 0x45, 0x47, 0x41, 0x43,
+	0x7d, 0x7f, 0x79, 0x7b, 0x75, 0x77, 0x71, 0x73, 0x6d, 0x6f, 0x69, 0x6b, 0x65, 0x67, 0x61, 0x63,
+	0x9d, 0x9f, 0x99, 0x9b, 0x95, 0x97, 0x91, 0x93, 0x8d, 0x8f, 0x89, 0x8b, 0x85, 0x87, 0x81, 0x83,
+	0xbd, 0xbf, 0xb9, 0xbb, 0xb5, 0xb7, 0xb1, 0xb3, 0xad, 0xaf, 0xa9, 0xab, 0xa5, 0xa7, 0xa1, 0xa3,
+	0xdd, 0xdf, 0xd9, 0xdb, 0xd5, 0xd7, 0xd1, 0xd3, 0xcd, 0xcf, 0xc9, 0xcb, 0xc5, 0xc7, 0xc1, 0xc3,
+	0xfd, 0xff, 0xf9, 0xfb, 0xf5, 0xf7, 0xf1, 0xf3, 0xed, 0xef, 0xe9, 0xeb, 0xe5, 0xe7, 0xe1, 0xe3
+};
+
+/** @brief  The ecchigh[ 256]. */
+static const uint8_t ecchigh[256] =
+{
+	0x00, 0xf4, 0xf5, 0x01, 0xf7, 0x03, 0x02, 0xf6, 0xf3, 0x07, 0x06, 0xf2, 0x04, 0xf0, 0xf1, 0x05,
+	0xfb, 0x0f, 0x0e, 0xfa, 0x0c, 0xf8, 0xf9, 0x0d, 0x08, 0xfc, 0xfd, 0x09, 0xff, 0x0b, 0x0a, 0xfe,
+	0xeb, 0x1f, 0x1e, 0xea, 0x1c, 0xe8, 0xe9, 0x1d, 0x18, 0xec, 0xed, 0x19, 0xef, 0x1b, 0x1a, 0xee,
+	0x10, 0xe4, 0xe5, 0x11, 0xe7, 0x13, 0x12, 0xe6, 0xe3, 0x17, 0x16, 0xe2, 0x14, 0xe0, 0xe1, 0x15,
+	0xcb, 0x3f, 0x3e, 0xca, 0x3c, 0xc8, 0xc9, 0x3d, 0x38, 0xcc, 0xcd, 0x39, 0xcf, 0x3b, 0x3a, 0xce,
+	0x30, 0xc4, 0xc5, 0x31, 0xc7, 0x33, 0x32, 0xc6, 0xc3, 0x37, 0x36, 0xc2, 0x34, 0xc0, 0xc1, 0x35,
+	0x20, 0xd4, 0xd5, 0x21, 0xd7, 0x23, 0x22, 0xd6, 0xd3, 0x27, 0x26, 0xd2, 0x24, 0xd0, 0xd1, 0x25,
+	0xdb, 0x2f, 0x2e, 0xda, 0x2c, 0xd8, 0xd9, 0x2d, 0x28, 0xdc, 0xdd, 0x29, 0xdf, 0x2b, 0x2a, 0xde,
+	0x8b, 0x7f, 0x7e, 0x8a, 0x7c, 0x88, 0x89, 0x7d, 0x78, 0x8c, 0x8d, 0x79, 0x8f, 0x7b, 0x7a, 0x8e,
+	0x70, 0x84, 0x85, 0x71, 0x87, 0x73, 0x72, 0x86, 0x83, 0x77, 0x76, 0x82, 0x74, 0x80, 0x81, 0x75,
+	0x60, 0x94, 0x95, 0x61, 0x97, 0x63, 0x62, 0x96, 0x93, 0x67, 0x66, 0x92, 0x64, 0x90, 0x91, 0x65,
+	0x9b, 0x6f, 0x6e, 0x9a, 0x6c, 0x98, 0x99, 0x6d, 0x68, 0x9c, 0x9d, 0x69, 0x9f, 0x6b, 0x6a, 0x9e,
+	0x40, 0xb4, 0xb5, 0x41, 0xb7, 0x43, 0x42, 0xb6, 0xb3, 0x47, 0x46, 0xb2, 0x44, 0xb0, 0xb1, 0x45,
+	0xbb, 0x4f, 0x4e, 0xba, 0x4c, 0xb8, 0xb9, 0x4d, 0x48, 0xbc, 0xbd, 0x49, 0xbf, 0x4b, 0x4a, 0xbe,
+	0xab, 0x5f, 0x5e, 0xaa, 0x5c, 0xa8, 0xa9, 0x5d, 0x58, 0xac, 0xad, 0x59, 0xaf, 0x5b, 0x5a, 0xae,
+	0x50, 0xa4, 0xa5, 0x51, 0xa7, 0x53, 0x52, 0xa6, 0xa3, 0x57, 0x56, 0xa2, 0x54, 0xa0, 0xa1, 0x55
+};
+
+/**
+ * @brief   -------------------------------------------------
+ *            poffsets - each row represents the addresses used to calculate a byte of the ECC P
+ *            data 86 (*2) ECC P bytes, 24 values represented by each
+ *          -------------------------------------------------.
+ */
+
+static const uint16_t poffsets[ECC_P_NUM_BYTES][ECC_P_COMP] =
+{
+	{ 0x000,0x056,0x0ac,0x102,0x158,0x1ae,0x204,0x25a,0x2b0,0x306,0x35c,0x3b2,0x408,0x45e,0x4b4,0x50a,0x560,0x5b6,0x60c,0x662,0x6b8,0x70e,0x764,0x7ba },
+	{ 0x001,0x057,0x0ad,0x103,0x159,0x1af,0x205,0x25b,0x2b1,0x307,0x35d,0x3b3,0x409,0x45f,0x4b5,0x50b,0x561,0x5b7,0x60d,0x663,0x6b9,0x70f,0x765,0x7bb },
+	{ 0x002,0x058,0x0ae,0x104,0x15a,0x1b0,0x206,0x25c,0x2b2,0x308,0x35e,0x3b4,0x40a,0x460,0x4b6,0x50c,0x562,0x5b8,0x60e,0x664,0x6ba,0x710,0x766,0x7bc },
+	{ 0x003,0x059,0x0af,0x105,0x15b,0x1b1,0x207,0x25d,0x2b3,0x309,0x35f,0x3b5,0x40b,0x461,0x4b7,0x50d,0x563,0x5b9,0x60f,0x665,0x6bb,0x711,0x767,0x7bd },
+	{ 0x004,0x05a,0x0b0,0x106,0x15c,0x1b2,0x208,0x25e,0x2b4,0x30a,0x360,0x3b6,0x40c,0x462,0x4b8,0x50e,0x564,0x5ba,0x610,0x666,0x6bc,0x712,0x768,0x7be },
+	{ 0x005,0x05b,0x0b1,0x107,0x15d,0x1b3,0x209,0x25f,0x2b5,0x30b,0x361,0x3b7,0x40d,0x463,0x4b9,0x50f,0x565,0x5bb,0x611,0x667,0x6bd,0x713,0x769,0x7bf },
+	{ 0x006,0x05c,0x0b2,0x108,0x15e,0x1b4,0x20a,0x260,0x2b6,0x30c,0x362,0x3b8,0x40e,0x464,0x4ba,0x510,0x566,0x5bc,0x612,0x668,0x6be,0x714,0x76a,0x7c0 },
+	{ 0x007,0x05d,0x0b3,0x109,0x15f,0x1b5,0x20b,0x261,0x2b7,0x30d,0x363,0x3b9,0x40f,0x465,0x4bb,0x511,0x567,0x5bd,0x613,0x669,0x6bf,0x715,0x76b,0x7c1 },
+	{ 0x008,0x05e,0x0b4,0x10a,0x160,0x1b6,0x20c,0x262,0x2b8,0x30e,0x364,0x3ba,0x410,0x466,0x4bc,0x512,0x568,0x5be,0x614,0x66a,0x6c0,0x716,0x76c,0x7c2 },
+	{ 0x009,0x05f,0x0b5,0x10b,0x161,0x1b7,0x20d,0x263,0x2b9,0x30f,0x365,0x3bb,0x411,0x467,0x4bd,0x513,0x569,0x5bf,0x615,0x66b,0x6c1,0x717,0x76d,0x7c3 },
+	{ 0x00a,0x060,0x0b6,0x10c,0x162,0x1b8,0x20e,0x264,0x2ba,0x310,0x366,0x3bc,0x412,0x468,0x4be,0x514,0x56a,0x5c0,0x616,0x66c,0x6c2,0x718,0x76e,0x7c4 },
+	{ 0x00b,0x061,0x0b7,0x10d,0x163,0x1b9,0x20f,0x265,0x2bb,0x311,0x367,0x3bd,0x413,0x469,0x4bf,0x515,0x56b,0x5c1,0x617,0x66d,0x6c3,0x719,0x76f,0x7c5 },
+	{ 0x00c,0x062,0x0b8,0x10e,0x164,0x1ba,0x210,0x266,0x2bc,0x312,0x368,0x3be,0x414,0x46a,0x4c0,0x516,0x56c,0x5c2,0x618,0x66e,0x6c4,0x71a,0x770,0x7c6 },
+	{ 0x00d,0x063,0x0b9,0x10f,0x165,0x1bb,0x211,0x267,0x2bd,0x313,0x369,0x3bf,0x415,0x46b,0x4c1,0x517,0x56d,0x5c3,0x619,0x66f,0x6c5,0x71b,0x771,0x7c7 },
+	{ 0x00e,0x064,0x0ba,0x110,0x166,0x1bc,0x212,0x268,0x2be,0x314,0x36a,0x3c0,0x416,0x46c,0x4c2,0x518,0x56e,0x5c4,0x61a,0x670,0x6c6,0x71c,0x772,0x7c8 },
+	{ 0x00f,0x065,0x0bb,0x111,0x167,0x1bd,0x213,0x269,0x2bf,0x315,0x36b,0x3c1,0x417,0x46d,0x4c3,0x519,0x56f,0x5c5,0x61b,0x671,0x6c7,0x71d,0x773,0x7c9 },
+	{ 0x010,0x066,0x0bc,0x112,0x168,0x1be,0x214,0x26a,0x2c0,0x316,0x36c,0x3c2,0x418,0x46e,0x4c4,0x51a,0x570,0x5c6,0x61c,0x672,0x6c8,0x71e,0x774,0x7ca },
+	{ 0x011,0x067,0x0bd,0x113,0x169,0x1bf,0x215,0x26b,0x2c1,0x317,0x36d,0x3c3,0x419,0x46f,0x4c5,0x51b,0x571,0x5c7,0x61d,0x673,0x6c9,0x71f,0x775,0x7cb },
+	{ 0x012,0x068,0x0be,0x114,0x16a,0x1c0,0x216,0x26c,0x2c2,0x318,0x36e,0x3c4,0x41a,0x470,0x4c6,0x51c,0x572,0x5c8,0x61e,0x674,0x6ca,0x720,0x776,0x7cc },
+	{ 0x013,0x069,0x0bf,0x115,0x16b,0x1c1,0x217,0x26d,0x2c3,0x319,0x36f,0x3c5,0x41b,0x471,0x4c7,0x51d,0x573,0x5c9,0x61f,0x675,0x6cb,0x721,0x777,0x7cd },
+	{ 0x014,0x06a,0x0c0,0x116,0x16c,0x1c2,0x218,0x26e,0x2c4,0x31a,0x370,0x3c6,0x41c,0x472,0x4c8,0x51e,0x574,0x5ca,0x620,0x676,0x6cc,0x722,0x778,0x7ce },
+	{ 0x015,0x06b,0x0c1,0x117,0x16d,0x1c3,0x219,0x26f,0x2c5,0x31b,0x371,0x3c7,0x41d,0x473,0x4c9,0x51f,0x575,0x5cb,0x621,0x677,0x6cd,0x723,0x779,0x7cf },
+	{ 0x016,0x06c,0x0c2,0x118,0x16e,0x1c4,0x21a,0x270,0x2c6,0x31c,0x372,0x3c8,0x41e,0x474,0x4ca,0x520,0x576,0x5cc,0x622,0x678,0x6ce,0x724,0x77a,0x7d0 },
+	{ 0x017,0x06d,0x0c3,0x119,0x16f,0x1c5,0x21b,0x271,0x2c7,0x31d,0x373,0x3c9,0x41f,0x475,0x4cb,0x521,0x577,0x5cd,0x623,0x679,0x6cf,0x725,0x77b,0x7d1 },
+	{ 0x018,0x06e,0x0c4,0x11a,0x170,0x1c6,0x21c,0x272,0x2c8,0x31e,0x374,0x3ca,0x420,0x476,0x4cc,0x522,0x578,0x5ce,0x624,0x67a,0x6d0,0x726,0x77c,0x7d2 },
+	{ 0x019,0x06f,0x0c5,0x11b,0x171,0x1c7,0x21d,0x273,0x2c9,0x31f,0x375,0x3cb,0x421,0x477,0x4cd,0x523,0x579,0x5cf,0x625,0x67b,0x6d1,0x727,0x77d,0x7d3 },
+	{ 0x01a,0x070,0x0c6,0x11c,0x172,0x1c8,0x21e,0x274,0x2ca,0x320,0x376,0x3cc,0x422,0x478,0x4ce,0x524,0x57a,0x5d0,0x626,0x67c,0x6d2,0x728,0x77e,0x7d4 },
+	{ 0x01b,0x071,0x0c7,0x11d,0x173,0x1c9,0x21f,0x275,0x2cb,0x321,0x377,0x3cd,0x423,0x479,0x4cf,0x525,0x57b,0x5d1,0x627,0x67d,0x6d3,0x729,0x77f,0x7d5 },
+	{ 0x01c,0x072,0x0c8,0x11e,0x174,0x1ca,0x220,0x276,0x2cc,0x322,0x378,0x3ce,0x424,0x47a,0x4d0,0x526,0x57c,0x5d2,0x628,0x67e,0x6d4,0x72a,0x780,0x7d6 },
+	{ 0x01d,0x073,0x0c9,0x11f,0x175,0x1cb,0x221,0x277,0x2cd,0x323,0x379,0x3cf,0x425,0x47b,0x4d1,0x527,0x57d,0x5d3,0x629,0x67f,0x6d5,0x72b,0x781,0x7d7 },
+	{ 0x01e,0x074,0x0ca,0x120,0x176,0x1cc,0x222,0x278,0x2ce,0x324,0x37a,0x3d0,0x426,0x47c,0x4d2,0x528,0x57e,0x5d4,0x62a,0x680,0x6d6,0x72c,0x782,0x7d8 },
+	{ 0x01f,0x075,0x0cb,0x121,0x177,0x1cd,0x223,0x279,0x2cf,0x325,0x37b,0x3d1,0x427,0x47d,0x4d3,0x529,0x57f,0x5d5,0x62b,0x681,0x6d7,0x72d,0x783,0x7d9 },
+	{ 0x020,0x076,0x0cc,0x122,0x178,0x1ce,0x224,0x27a,0x2d0,0x326,0x37c,0x3d2,0x428,0x47e,0x4d4,0x52a,0x580,0x5d6,0x62c,0x682,0x6d8,0x72e,0x784,0x7da },
+	{ 0x021,0x077,0x0cd,0x123,0x179,0x1cf,0x225,0x27b,0x2d1,0x327,0x37d,0x3d3,0x429,0x47f,0x4d5,0x52b,0x581,0x5d7,0x62d,0x683,0x6d9,0x72f,0x785,0x7db },
+	{ 0x022,0x078,0x0ce,0x124,0x17a,0x1d0,0x226,0x27c,0x2d2,0x328,0x37e,0x3d4,0x42a,0x480,0x4d6,0x52c,0x582,0x5d8,0x62e,0x684,0x6da,0x730,0x786,0x7dc },
+	{ 0x023,0x079,0x0cf,0x125,0x17b,0x1d1,0x227,0x27d,0x2d3,0x329,0x37f,0x3d5,0x42b,0x481,0x4d7,0x52d,0x583,0x5d9,0x62f,0x685,0x6db,0x731,0x787,0x7dd },
+	{ 0x024,0x07a,0x0d0,0x126,0x17c,0x1d2,0x228,0x27e,0x2d4,0x32a,0x380,0x3d6,0x42c,0x482,0x4d8,0x52e,0x584,0x5da,0x630,0x686,0x6dc,0x732,0x788,0x7de },
+	{ 0x025,0x07b,0x0d1,0x127,0x17d,0x1d3,0x229,0x27f,0x2d5,0x32b,0x381,0x3d7,0x42d,0x483,0x4d9,0x52f,0x585,0x5db,0x631,0x687,0x6dd,0x733,0x789,0x7df },
+	{ 0x026,0x07c,0x0d2,0x128,0x17e,0x1d4,0x22a,0x280,0x2d6,0x32c,0x382,0x3d8,0x42e,0x484,0x4da,0x530,0x586,0x5dc,0x632,0x688,0x6de,0x734,0x78a,0x7e0 },
+	{ 0x027,0x07d,0x0d3,0x129,0x17f,0x1d5,0x22b,0x281,0x2d7,0x32d,0x383,0x3d9,0x42f,0x485,0x4db,0x531,0x587,0x5dd,0x633,0x689,0x6df,0x735,0x78b,0x7e1 },
+	{ 0x028,0x07e,0x0d4,0x12a,0x180,0x1d6,0x22c,0x282,0x2d8,0x32e,0x384,0x3da,0x430,0x486,0x4dc,0x532,0x588,0x5de,0x634,0x68a,0x6e0,0x736,0x78c,0x7e2 },
+	{ 0x029,0x07f,0x0d5,0x12b,0x181,0x1d7,0x22d,0x283,0x2d9,0x32f,0x385,0x3db,0x431,0x487,0x4dd,0x533,0x589,0x5df,0x635,0x68b,0x6e1,0x737,0x78d,0x7e3 },
+	{ 0x02a,0x080,0x0d6,0x12c,0x182,0x1d8,0x22e,0x284,0x2da,0x330,0x386,0x3dc,0x432,0x488,0x4de,0x534,0x58a,0x5e0,0x636,0x68c,0x6e2,0x738,0x78e,0x7e4 },
+	{ 0x02b,0x081,0x0d7,0x12d,0x183,0x1d9,0x22f,0x285,0x2db,0x331,0x387,0x3dd,0x433,0x489,0x4df,0x535,0x58b,0x5e1,0x637,0x68d,0x6e3,0x739,0x78f,0x7e5 },
+	{ 0x02c,0x082,0x0d8,0x12e,0x184,0x1da,0x230,0x286,0x2dc,0x332,0x388,0x3de,0x434,0x48a,0x4e0,0x536,0x58c,0x5e2,0x638,0x68e,0x6e4,0x73a,0x790,0x7e6 },
+	{ 0x02d,0x083,0x0d9,0x12f,0x185,0x1db,0x231,0x287,0x2dd,0x333,0x389,0x3df,0x435,0x48b,0x4e1,0x537,0x58d,0x5e3,0x639,0x68f,0x6e5,0x73b,0x791,0x7e7 },
+	{ 0x02e,0x084,0x0da,0x130,0x186,0x1dc,0x232,0x288,0x2de,0x334,0x38a,0x3e0,0x436,0x48c,0x4e2,0x538,0x58e,0x5e4,0x63a,0x690,0x6e6,0x73c,0x792,0x7e8 },
+	{ 0x02f,0x085,0x0db,0x131,0x187,0x1dd,0x233,0x289,0x2df,0x335,0x38b,0x3e1,0x437,0x48d,0x4e3,0x539,0x58f,0x5e5,0x63b,0x691,0x6e7,0x73d,0x793,0x7e9 },
+	{ 0x030,0x086,0x0dc,0x132,0x188,0x1de,0x234,0x28a,0x2e0,0x336,0x38c,0x3e2,0x438,0x48e,0x4e4,0x53a,0x590,0x5e6,0x63c,0x692,0x6e8,0x73e,0x794,0x7ea },
+	{ 0x031,0x087,0x0dd,0x133,0x189,0x1df,0x235,0x28b,0x2e1,0x337,0x38d,0x3e3,0x439,0x48f,0x4e5,0x53b,0x591,0x5e7,0x63d,0x693,0x6e9,0x73f,0x795,0x7eb },
+	{ 0x032,0x088,0x0de,0x134,0x18a,0x1e0,0x236,0x28c,0x2e2,0x338,0x38e,0x3e4,0x43a,0x490,0x4e6,0x53c,0x592,0x5e8,0x63e,0x694,0x6ea,0x740,0x796,0x7ec },
+	{ 0x033,0x089,0x0df,0x135,0x18b,0x1e1,0x237,0x28d,0x2e3,0x339,0x38f,0x3e5,0x43b,0x491,0x4e7,0x53d,0x593,0x5e9,0x63f,0x695,0x6eb,0x741,0x797,0x7ed },
+	{ 0x034,0x08a,0x0e0,0x136,0x18c,0x1e2,0x238,0x28e,0x2e4,0x33a,0x390,0x3e6,0x43c,0x492,0x4e8,0x53e,0x594,0x5ea,0x640,0x696,0x6ec,0x742,0x798,0x7ee },
+	{ 0x035,0x08b,0x0e1,0x137,0x18d,0x1e3,0x239,0x28f,0x2e5,0x33b,0x391,0x3e7,0x43d,0x493,0x4e9,0x53f,0x595,0x5eb,0x641,0x697,0x6ed,0x743,0x799,0x7ef },
+	{ 0x036,0x08c,0x0e2,0x138,0x18e,0x1e4,0x23a,0x290,0x2e6,0x33c,0x392,0x3e8,0x43e,0x494,0x4ea,0x540,0x596,0x5ec,0x642,0x698,0x6ee,0x744,0x79a,0x7f0 },
+	{ 0x037,0x08d,0x0e3,0x139,0x18f,0x1e5,0x23b,0x291,0x2e7,0x33d,0x393,0x3e9,0x43f,0x495,0x4eb,0x541,0x597,0x5ed,0x643,0x699,0x6ef,0x745,0x79b,0x7f1 },
+	{ 0x038,0x08e,0x0e4,0x13a,0x190,0x1e6,0x23c,0x292,0x2e8,0x33e,0x394,0x3ea,0x440,0x496,0x4ec,0x542,0x598,0x5ee,0x644,0x69a,0x6f0,0x746,0x79c,0x7f2 },
+	{ 0x039,0x08f,0x0e5,0x13b,0x191,0x1e7,0x23d,0x293,0x2e9,0x33f,0x395,0x3eb,0x441,0x497,0x4ed,0x543,0x599,0x5ef,0x645,0x69b,0x6f1,0x747,0x79d,0x7f3 },
+	{ 0x03a,0x090,0x0e6,0x13c,0x192,0x1e8,0x23e,0x294,0x2ea,0x340,0x396,0x3ec,0x442,0x498,0x4ee,0x544,0x59a,0x5f0,0x646,0x69c,0x6f2,0x748,0x79e,0x7f4 },
+	{ 0x03b,0x091,0x0e7,0x13d,0x193,0x1e9,0x23f,0x295,0x2eb,0x341,0x397,0x3ed,0x443,0x499,0x4ef,0x545,0x59b,0x5f1,0x647,0x69d,0x6f3,0x749,0x79f,0x7f5 },
+	{ 0x03c,0x092,0x0e8,0x13e,0x194,0x1ea,0x240,0x296,0x2ec,0x342,0x398,0x3ee,0x444,0x49a,0x4f0,0x546,0x59c,0x5f2,0x648,0x69e,0x6f4,0x74a,0x7a0,0x7f6 },
+	{ 0x03d,0x093,0x0e9,0x13f,0x195,0x1eb,0x241,0x297,0x2ed,0x343,0x399,0x3ef,0x445,0x49b,0x4f1,0x547,0x59d,0x5f3,0x649,0x69f,0x6f5,0x74b,0x7a1,0x7f7 },
+	{ 0x03e,0x094,0x0ea,0x140,0x196,0x1ec,0x242,0x298,0x2ee,0x344,0x39a,0x3f0,0x446,0x49c,0x4f2,0x548,0x59e,0x5f4,0x64a,0x6a0,0x6f6,0x74c,0x7a2,0x7f8 },
+	{ 0x03f,0x095,0x0eb,0x141,0x197,0x1ed,0x243,0x299,0x2ef,0x345,0x39b,0x3f1,0x447,0x49d,0x4f3,0x549,0x59f,0x5f5,0x64b,0x6a1,0x6f7,0x74d,0x7a3,0x7f9 },
+	{ 0x040,0x096,0x0ec,0x142,0x198,0x1ee,0x244,0x29a,0x2f0,0x346,0x39c,0x3f2,0x448,0x49e,0x4f4,0x54a,0x5a0,0x5f6,0x64c,0x6a2,0x6f8,0x74e,0x7a4,0x7fa },
+	{ 0x041,0x097,0x0ed,0x143,0x199,0x1ef,0x245,0x29b,0x2f1,0x347,0x39d,0x3f3,0x449,0x49f,0x4f5,0x54b,0x5a1,0x5f7,0x64d,0x6a3,0x6f9,0x74f,0x7a5,0x7fb },
+	{ 0x042,0x098,0x0ee,0x144,0x19a,0x1f0,0x246,0x29c,0x2f2,0x348,0x39e,0x3f4,0x44a,0x4a0,0x4f6,0x54c,0x5a2,0x5f8,0x64e,0x6a4,0x6fa,0x750,0x7a6,0x7fc },
+	{ 0x043,0x099,0x0ef,0x145,0x19b,0x1f1,0x247,0x29d,0x2f3,0x349,0x39f,0x3f5,0x44b,0x4a1,0x4f7,0x54d,0x5a3,0x5f9,0x64f,0x6a5,0x6fb,0x751,0x7a7,0x7fd },
+	{ 0x044,0x09a,0x0f0,0x146,0x19c,0x1f2,0x248,0x29e,0x2f4,0x34a,0x3a0,0x3f6,0x44c,0x4a2,0x4f8,0x54e,0x5a4,0x5fa,0x650,0x6a6,0x6fc,0x752,0x7a8,0x7fe },
+	{ 0x045,0x09b,0x0f1,0x147,0x19d,0x1f3,0x249,0x29f,0x2f5,0x34b,0x3a1,0x3f7,0x44d,0x4a3,0x4f9,0x54f,0x5a5,0x5fb,0x651,0x6a7,0x6fd,0x753,0x7a9,0x7ff },
+	{ 0x046,0x09c,0x0f2,0x148,0x19e,0x1f4,0x24a,0x2a0,0x2f6,0x34c,0x3a2,0x3f8,0x44e,0x4a4,0x4fa,0x550,0x5a6,0x5fc,0x652,0x6a8,0x6fe,0x754,0x7aa,0x800 },
+	{ 0x047,0x09d,0x0f3,0x149,0x19f,0x1f5,0x24b,0x2a1,0x2f7,0x34d,0x3a3,0x3f9,0x44f,0x4a5,0x4fb,0x551,0x5a7,0x5fd,0x653,0x6a9,0x6ff,0x755,0x7ab,0x801 },
+	{ 0x048,0x09e,0x0f4,0x14a,0x1a0,0x1f6,0x24c,0x2a2,0x2f8,0x34e,0x3a4,0x3fa,0x450,0x4a6,0x4fc,0x552,0x5a8,0x5fe,0x654,0x6aa,0x700,0x756,0x7ac,0x802 },
+	{ 0x049,0x09f,0x0f5,0x14b,0x1a1,0x1f7,0x24d,0x2a3,0x2f9,0x34f,0x3a5,0x3fb,0x451,0x4a7,0x4fd,0x553,0x5a9,0x5ff,0x655,0x6ab,0x701,0x757,0x7ad,0x803 },
+	{ 0x04a,0x0a0,0x0f6,0x14c,0x1a2,0x1f8,0x24e,0x2a4,0x2fa,0x350,0x3a6,0x3fc,0x452,0x4a8,0x4fe,0x554,0x5aa,0x600,0x656,0x6ac,0x702,0x758,0x7ae,0x804 },
+	{ 0x04b,0x0a1,0x0f7,0x14d,0x1a3,0x1f9,0x24f,0x2a5,0x2fb,0x351,0x3a7,0x3fd,0x453,0x4a9,0x4ff,0x555,0x5ab,0x601,0x657,0x6ad,0x703,0x759,0x7af,0x805 },
+	{ 0x04c,0x0a2,0x0f8,0x14e,0x1a4,0x1fa,0x250,0x2a6,0x2fc,0x352,0x3a8,0x3fe,0x454,0x4aa,0x500,0x556,0x5ac,0x602,0x658,0x6ae,0x704,0x75a,0x7b0,0x806 },
+	{ 0x04d,0x0a3,0x0f9,0x14f,0x1a5,0x1fb,0x251,0x2a7,0x2fd,0x353,0x3a9,0x3ff,0x455,0x4ab,0x501,0x557,0x5ad,0x603,0x659,0x6af,0x705,0x75b,0x7b1,0x807 },
+	{ 0x04e,0x0a4,0x0fa,0x150,0x1a6,0x1fc,0x252,0x2a8,0x2fe,0x354,0x3aa,0x400,0x456,0x4ac,0x502,0x558,0x5ae,0x604,0x65a,0x6b0,0x706,0x75c,0x7b2,0x808 },
+	{ 0x04f,0x0a5,0x0fb,0x151,0x1a7,0x1fd,0x253,0x2a9,0x2ff,0x355,0x3ab,0x401,0x457,0x4ad,0x503,0x559,0x5af,0x605,0x65b,0x6b1,0x707,0x75d,0x7b3,0x809 },
+	{ 0x050,0x0a6,0x0fc,0x152,0x1a8,0x1fe,0x254,0x2aa,0x300,0x356,0x3ac,0x402,0x458,0x4ae,0x504,0x55a,0x5b0,0x606,0x65c,0x6b2,0x708,0x75e,0x7b4,0x80a },
+	{ 0x051,0x0a7,0x0fd,0x153,0x1a9,0x1ff,0x255,0x2ab,0x301,0x357,0x3ad,0x403,0x459,0x4af,0x505,0x55b,0x5b1,0x607,0x65d,0x6b3,0x709,0x75f,0x7b5,0x80b },
+	{ 0x052,0x0a8,0x0fe,0x154,0x1aa,0x200,0x256,0x2ac,0x302,0x358,0x3ae,0x404,0x45a,0x4b0,0x506,0x55c,0x5b2,0x608,0x65e,0x6b4,0x70a,0x760,0x7b6,0x80c },
+	{ 0x053,0x0a9,0x0ff,0x155,0x1ab,0x201,0x257,0x2ad,0x303,0x359,0x3af,0x405,0x45b,0x4b1,0x507,0x55d,0x5b3,0x609,0x65f,0x6b5,0x70b,0x761,0x7b7,0x80d },
+	{ 0x054,0x0aa,0x100,0x156,0x1ac,0x202,0x258,0x2ae,0x304,0x35a,0x3b0,0x406,0x45c,0x4b2,0x508,0x55e,0x5b4,0x60a,0x660,0x6b6,0x70c,0x762,0x7b8,0x80e },
+	{ 0x055,0x0ab,0x101,0x157,0x1ad,0x203,0x259,0x2af,0x305,0x35b,0x3b1,0x407,0x45d,0x4b3,0x509,0x55f,0x5b5,0x60b,0x661,0x6b7,0x70d,0x763,0x7b9,0x80f }
+};
+
+/**
+ * @brief   -------------------------------------------------
+ *            qoffsets - each row represents the addresses used to calculate a byte of the ECC Q
+ *            data 52 (*2) ECC Q bytes, 43 values represented by each
+ *          -------------------------------------------------.
+ */
+
+static const uint16_t qoffsets[ECC_Q_NUM_BYTES][ECC_Q_COMP] =
+{
+	{ 0x000,0x058,0x0b0,0x108,0x160,0x1b8,0x210,0x268,0x2c0,0x318,0x370,0x3c8,0x420,0x478,0x4d0,0x528,0x580,0x5d8,0x630,0x688,0x6e0,0x738,0x790,0x7e8,0x840,0x898,0x034,0x08c,0x0e4,0x13c,0x194,0x1ec,0x244,0x29c,0x2f4,0x34c,0x3a4,0x3fc,0x454,0x4ac,0x504,0x55c,0x5b4 },
+	{ 0x001,0x059,0x0b1,0x109,0x161,0x1b9,0x211,0x269,0x2c1,0x319,0x371,0x3c9,0x421,0x479,0x4d1,0x529,0x581,0x5d9,0x631,0x689,0x6e1,0x739,0x791,0x7e9,0x841,0x899,0x035,0x08d,0x0e5,0x13d,0x195,0x1ed,0x245,0x29d,0x2f5,0x34d,0x3a5,0x3fd,0x455,0x4ad,0x505,0x55d,0x5b5 },
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+	{ 0x60c,0x664,0x6bc,0x714,0x76c,0x7c4,0x81c,0x874,0x010,0x068,0x0c0,0x118,0x170,0x1c8,0x220,0x278,0x2d0,0x328,0x380,0x3d8,0x430,0x488,0x4e0,0x538,0x590,0x5e8,0x640,0x698,0x6f0,0x748,0x7a0,0x7f8,0x850,0x8a8,0x044,0x09c,0x0f4,0x14c,0x1a4,0x1fc,0x254,0x2ac,0x304 },
+	{ 0x60d,0x665,0x6bd,0x715,0x76d,0x7c5,0x81d,0x875,0x011,0x069,0x0c1,0x119,0x171,0x1c9,0x221,0x279,0x2d1,0x329,0x381,0x3d9,0x431,0x489,0x4e1,0x539,0x591,0x5e9,0x641,0x699,0x6f1,0x749,0x7a1,0x7f9,0x851,0x8a9,0x045,0x09d,0x0f5,0x14d,0x1a5,0x1fd,0x255,0x2ad,0x305 },
+	{ 0x662,0x6ba,0x712,0x76a,0x7c2,0x81a,0x872,0x00e,0x066,0x0be,0x116,0x16e,0x1c6,0x21e,0x276,0x2ce,0x326,0x37e,0x3d6,0x42e,0x486,0x4de,0x536,0x58e,0x5e6,0x63e,0x696,0x6ee,0x746,0x79e,0x7f6,0x84e,0x8a6,0x042,0x09a,0x0f2,0x14a,0x1a2,0x1fa,0x252,0x2aa,0x302,0x35a },
+	{ 0x663,0x6bb,0x713,0x76b,0x7c3,0x81b,0x873,0x00f,0x067,0x0bf,0x117,0x16f,0x1c7,0x21f,0x277,0x2cf,0x327,0x37f,0x3d7,0x42f,0x487,0x4df,0x537,0x58f,0x5e7,0x63f,0x697,0x6ef,0x747,0x79f,0x7f7,0x84f,0x8a7,0x043,0x09b,0x0f3,0x14b,0x1a3,0x1fb,0x253,0x2ab,0x303,0x35b },
+	{ 0x6b8,0x710,0x768,0x7c0,0x818,0x870,0x00c,0x064,0x0bc,0x114,0x16c,0x1c4,0x21c,0x274,0x2cc,0x324,0x37c,0x3d4,0x42c,0x484,0x4dc,0x534,0x58c,0x5e4,0x63c,0x694,0x6ec,0x744,0x79c,0x7f4,0x84c,0x8a4,0x040,0x098,0x0f0,0x148,0x1a0,0x1f8,0x250,0x2a8,0x300,0x358,0x3b0 },
+	{ 0x6b9,0x711,0x769,0x7c1,0x819,0x871,0x00d,0x065,0x0bd,0x115,0x16d,0x1c5,0x21d,0x275,0x2cd,0x325,0x37d,0x3d5,0x42d,0x485,0x4dd,0x535,0x58d,0x5e5,0x63d,0x695,0x6ed,0x745,0x79d,0x7f5,0x84d,0x8a5,0x041,0x099,0x0f1,0x149,0x1a1,0x1f9,0x251,0x2a9,0x301,0x359,0x3b1 },
+	{ 0x70e,0x766,0x7be,0x816,0x86e,0x00a,0x062,0x0ba,0x112,0x16a,0x1c2,0x21a,0x272,0x2ca,0x322,0x37a,0x3d2,0x42a,0x482,0x4da,0x532,0x58a,0x5e2,0x63a,0x692,0x6ea,0x742,0x79a,0x7f2,0x84a,0x8a2,0x03e,0x096,0x0ee,0x146,0x19e,0x1f6,0x24e,0x2a6,0x2fe,0x356,0x3ae,0x406 },
+	{ 0x70f,0x767,0x7bf,0x817,0x86f,0x00b,0x063,0x0bb,0x113,0x16b,0x1c3,0x21b,0x273,0x2cb,0x323,0x37b,0x3d3,0x42b,0x483,0x4db,0x533,0x58b,0x5e3,0x63b,0x693,0x6eb,0x743,0x79b,0x7f3,0x84b,0x8a3,0x03f,0x097,0x0ef,0x147,0x19f,0x1f7,0x24f,0x2a7,0x2ff,0x357,0x3af,0x407 },
+	{ 0x764,0x7bc,0x814,0x86c,0x008,0x060,0x0b8,0x110,0x168,0x1c0,0x218,0x270,0x2c8,0x320,0x378,0x3d0,0x428,0x480,0x4d8,0x530,0x588,0x5e0,0x638,0x690,0x6e8,0x740,0x798,0x7f0,0x848,0x8a0,0x03c,0x094,0x0ec,0x144,0x19c,0x1f4,0x24c,0x2a4,0x2fc,0x354,0x3ac,0x404,0x45c },
+	{ 0x765,0x7bd,0x815,0x86d,0x009,0x061,0x0b9,0x111,0x169,0x1c1,0x219,0x271,0x2c9,0x321,0x379,0x3d1,0x429,0x481,0x4d9,0x531,0x589,0x5e1,0x639,0x691,0x6e9,0x741,0x799,0x7f1,0x849,0x8a1,0x03d,0x095,0x0ed,0x145,0x19d,0x1f5,0x24d,0x2a5,0x2fd,0x355,0x3ad,0x405,0x45d },
+	{ 0x7ba,0x812,0x86a,0x006,0x05e,0x0b6,0x10e,0x166,0x1be,0x216,0x26e,0x2c6,0x31e,0x376,0x3ce,0x426,0x47e,0x4d6,0x52e,0x586,0x5de,0x636,0x68e,0x6e6,0x73e,0x796,0x7ee,0x846,0x89e,0x03a,0x092,0x0ea,0x142,0x19a,0x1f2,0x24a,0x2a2,0x2fa,0x352,0x3aa,0x402,0x45a,0x4b2 },
+	{ 0x7bb,0x813,0x86b,0x007,0x05f,0x0b7,0x10f,0x167,0x1bf,0x217,0x26f,0x2c7,0x31f,0x377,0x3cf,0x427,0x47f,0x4d7,0x52f,0x587,0x5df,0x637,0x68f,0x6e7,0x73f,0x797,0x7ef,0x847,0x89f,0x03b,0x093,0x0eb,0x143,0x19b,0x1f3,0x24b,0x2a3,0x2fb,0x353,0x3ab,0x403,0x45b,0x4b3 },
+	{ 0x810,0x868,0x004,0x05c,0x0b4,0x10c,0x164,0x1bc,0x214,0x26c,0x2c4,0x31c,0x374,0x3cc,0x424,0x47c,0x4d4,0x52c,0x584,0x5dc,0x634,0x68c,0x6e4,0x73c,0x794,0x7ec,0x844,0x89c,0x038,0x090,0x0e8,0x140,0x198,0x1f0,0x248,0x2a0,0x2f8,0x350,0x3a8,0x400,0x458,0x4b0,0x508 },
+	{ 0x811,0x869,0x005,0x05d,0x0b5,0x10d,0x165,0x1bd,0x215,0x26d,0x2c5,0x31d,0x375,0x3cd,0x425,0x47d,0x4d5,0x52d,0x585,0x5dd,0x635,0x68d,0x6e5,0x73d,0x795,0x7ed,0x845,0x89d,0x039,0x091,0x0e9,0x141,0x199,0x1f1,0x249,0x2a1,0x2f9,0x351,0x3a9,0x401,0x459,0x4b1,0x509 },
+	{ 0x866,0x002,0x05a,0x0b2,0x10a,0x162,0x1ba,0x212,0x26a,0x2c2,0x31a,0x372,0x3ca,0x422,0x47a,0x4d2,0x52a,0x582,0x5da,0x632,0x68a,0x6e2,0x73a,0x792,0x7ea,0x842,0x89a,0x036,0x08e,0x0e6,0x13e,0x196,0x1ee,0x246,0x29e,0x2f6,0x34e,0x3a6,0x3fe,0x456,0x4ae,0x506,0x55e },
+	{ 0x867,0x003,0x05b,0x0b3,0x10b,0x163,0x1bb,0x213,0x26b,0x2c3,0x31b,0x373,0x3cb,0x423,0x47b,0x4d3,0x52b,0x583,0x5db,0x633,0x68b,0x6e3,0x73b,0x793,0x7eb,0x843,0x89b,0x037,0x08f,0x0e7,0x13f,0x197,0x1ef,0x247,0x29f,0x2f7,0x34f,0x3a7,0x3ff,0x457,0x4af,0x507,0x55f }
+};
+
+/*-------------------------------------------------
+ *  ecc_source_byte - return data from the sector
+ *  at the given offset, masking anything
+ *  particular to a mode
+ *-------------------------------------------------
+ */
+
+static inline uint8_t ecc_source_byte(const uint8_t *sector, uint32_t offset)
+{
+	/* in mode 2 always treat these as 0 bytes */
+	return (sector[MODE_OFFSET] == 2 && offset < 4) ? 0x00 : sector[SYNC_OFFSET + SYNC_NUM_BYTES + offset];
+}
+
+/**
+ * @fn  void ecc_compute_bytes(const uint8_t *sector, const uint16_t *row, int rowlen, uint8_t &val1, uint8_t &val2)
+ *
+ * @brief   -------------------------------------------------
+ *            ecc_compute_bytes - calculate an ECC value (P or Q)
+ *          -------------------------------------------------.
+ *
+ * @param   sector          The sector.
+ * @param   row             The row.
+ * @param   rowlen          The rowlen.
+ * @param [in,out]  val1    The first value.
+ * @param [in,out]  val2    The second value.
+ */
+
+void ecc_compute_bytes(const uint8_t *sector, const uint16_t *row, int rowlen, uint8_t *val1, uint8_t *val2)
+{
+	int component;
+	*val1 = *val2 = 0;
+	for (component = 0; component < rowlen; component++)
+	{
+		*val1 ^= ecc_source_byte(sector, row[component]);
+		*val2 ^= ecc_source_byte(sector, row[component]);
+		*val1 = ecclow[*val1];
+	}
+	*val1 = ecchigh[ecclow[*val1] ^ *val2];
+	*val2 ^= *val1;
+}
+
+/**
+ * @fn  int ecc_verify(const uint8_t *sector)
+ *
+ * @brief   -------------------------------------------------
+ *            ecc_verify - verify the P and Q ECC codes in a sector
+ *          -------------------------------------------------.
+ *
+ * @param   sector  The sector.
+ *
+ * @return  true if it succeeds, false if it fails.
+ */
+
+int ecc_verify(const uint8_t *sector)
+{
+	int byte;
+	/* first verify P bytes */
+	for (byte = 0; byte < ECC_P_NUM_BYTES; byte++)
+	{
+		uint8_t val1, val2;
+		ecc_compute_bytes(sector, poffsets[byte], ECC_P_COMP, &val1, &val2);
+		if (sector[ECC_P_OFFSET + byte] != val1 || sector[ECC_P_OFFSET + ECC_P_NUM_BYTES + byte] != val2)
+			return 0;
+	}
+
+	/* then verify Q bytes */
+	for (byte = 0; byte < ECC_Q_NUM_BYTES; byte++)
+	{
+		uint8_t val1, val2;
+		ecc_compute_bytes(sector, qoffsets[byte], ECC_Q_COMP, &val1, &val2);
+		if (sector[ECC_Q_OFFSET + byte] != val1 || sector[ECC_Q_OFFSET + ECC_Q_NUM_BYTES + byte] != val2)
+			return 0;
+	}
+	return 1;
+}
+
+/**
+ * @fn  void ecc_generate(uint8_t *sector)
+ *
+ * @brief   -------------------------------------------------
+ *            ecc_generate - generate the P and Q ECC codes for a sector, overwriting any
+ *            existing codes
+ *          -------------------------------------------------.
+ *
+ * @param [in,out]  sector  If non-null, the sector.
+ */
+
+void ecc_generate(uint8_t *sector)
+{
+	int byte;
+	/* first verify P bytes */
+	for (byte = 0; byte < ECC_P_NUM_BYTES; byte++)
+		ecc_compute_bytes(sector, poffsets[byte], ECC_P_COMP, &sector[ECC_P_OFFSET + byte], &sector[ECC_P_OFFSET + ECC_P_NUM_BYTES + byte]);
+
+	/* then verify Q bytes */
+	for (byte = 0; byte < ECC_Q_NUM_BYTES; byte++)
+		ecc_compute_bytes(sector, qoffsets[byte], ECC_Q_COMP, &sector[ECC_Q_OFFSET + byte], &sector[ECC_Q_OFFSET + ECC_Q_NUM_BYTES + byte]);
+}
+
+/**
+ * @fn  void ecc_clear(uint8_t *sector)
+ *
+ * @brief   -------------------------------------------------
+ *            ecc_clear - erase the ECC P and Q cods to 0 within a sector
+ *          -------------------------------------------------.
+ *
+ * @param [in,out]  sector  If non-null, the sector.
+ */
+
+void ecc_clear(uint8_t *sector)
+{
+	memset(&sector[ECC_P_OFFSET], 0, 2 * ECC_P_NUM_BYTES);
+	memset(&sector[ECC_Q_OFFSET], 0, 2 * ECC_Q_NUM_BYTES);
+}
+
+#endif /* WANT_RAW_DATA_SECTOR */
diff --git a/deps/libchdr/src/libchdr_chd.c b/deps/libchdr/src/libchdr_chd.c
new file mode 100644
index 0000000..913abaa
--- /dev/null
+++ b/deps/libchdr/src/libchdr_chd.c
@@ -0,0 +1,2672 @@
+/***************************************************************************
+
+    chd.c
+
+    MAME Compressed Hunks of Data file format
+
+****************************************************************************
+
+    Copyright Aaron Giles
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are
+    met:
+
+        * Redistributions of source code must retain the above copyright
+          notice, this list of conditions and the following disclaimer.
+        * Redistributions in binary form must reproduce the above copyright
+          notice, this list of conditions and the following disclaimer in
+          the documentation and/or other materials provided with the
+          distribution.
+        * Neither the name 'MAME' nor the names of its contributors may be
+          used to endorse or promote products derived from this software
+          without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+    DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
+    INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+    IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+    POSSIBILITY OF SUCH DAMAGE.
+
+***************************************************************************/
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include <libchdr/chd.h>
+#include <libchdr/cdrom.h>
+#include <libchdr/flac.h>
+#include <libchdr/huffman.h>
+
+#include "LzmaEnc.h"
+#include "LzmaDec.h"
+#include "zlib.h"
+
+#undef TRUE
+#undef FALSE
+#define TRUE 1
+#define FALSE 0
+
+#undef MAX
+#undef MIN
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+#define SHA1_DIGEST_SIZE 20
+
+/***************************************************************************
+    DEBUGGING
+***************************************************************************/
+
+#define PRINTF_MAX_HUNK				(0)
+
+/***************************************************************************
+    CONSTANTS
+***************************************************************************/
+
+#define MAP_STACK_ENTRIES			512			/* max number of entries to use on the stack */
+#define MAP_ENTRY_SIZE				16			/* V3 and later */
+#define OLD_MAP_ENTRY_SIZE			8			/* V1-V2 */
+#define METADATA_HEADER_SIZE		16			/* metadata header size */
+
+#define MAP_ENTRY_FLAG_TYPE_MASK	0x0f		/* what type of hunk */
+#define MAP_ENTRY_FLAG_NO_CRC		0x10		/* no CRC is present */
+
+#define CHD_V1_SECTOR_SIZE			512			/* size of a "sector" in the V1 header */
+
+#define COOKIE_VALUE				0xbaadf00d
+#define MAX_ZLIB_ALLOCS				64
+
+#define END_OF_LIST_COOKIE			"EndOfListCookie"
+
+#define NO_MATCH					(~0)
+
+#ifdef WANT_RAW_DATA_SECTOR
+static const uint8_t s_cd_sync_header[12] = { 0x00,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x00 };
+#endif
+
+/* V3-V4 entry types */
+enum
+{
+	V34_MAP_ENTRY_TYPE_INVALID = 0,             /* invalid type */
+	V34_MAP_ENTRY_TYPE_COMPRESSED = 1,          /* standard compression */
+	V34_MAP_ENTRY_TYPE_UNCOMPRESSED = 2,        /* uncompressed data */
+	V34_MAP_ENTRY_TYPE_MINI = 3,                /* mini: use offset as raw data */
+	V34_MAP_ENTRY_TYPE_SELF_HUNK = 4,           /* same as another hunk in this file */
+	V34_MAP_ENTRY_TYPE_PARENT_HUNK = 5,         /* same as a hunk in the parent file */
+	V34_MAP_ENTRY_TYPE_2ND_COMPRESSED = 6       /* compressed with secondary algorithm (usually FLAC CDDA) */
+};
+
+/* V5 compression types */
+enum
+{
+	/* codec #0
+	 * these types are live when running */
+	COMPRESSION_TYPE_0 = 0,
+	/* codec #1 */
+	COMPRESSION_TYPE_1 = 1,
+	/* codec #2 */
+	COMPRESSION_TYPE_2 = 2,
+	/* codec #3 */
+	COMPRESSION_TYPE_3 = 3,
+	/* no compression; implicit length = hunkbytes */
+	COMPRESSION_NONE = 4,
+	/* same as another block in this chd */
+	COMPRESSION_SELF = 5,
+	/* same as a hunk's worth of units in the parent chd */
+	COMPRESSION_PARENT = 6,
+
+	/* start of small RLE run (4-bit length)
+	 * these additional pseudo-types are used for compressed encodings: */
+	COMPRESSION_RLE_SMALL,
+	/* start of large RLE run (8-bit length) */
+	COMPRESSION_RLE_LARGE,
+	/* same as the last COMPRESSION_SELF block */
+	COMPRESSION_SELF_0,
+	/* same as the last COMPRESSION_SELF block + 1 */
+	COMPRESSION_SELF_1,
+	/* same block in the parent */
+	COMPRESSION_PARENT_SELF,
+	/* same as the last COMPRESSION_PARENT block */
+	COMPRESSION_PARENT_0,
+	/* same as the last COMPRESSION_PARENT block + 1 */
+	COMPRESSION_PARENT_1
+};
+
+/***************************************************************************
+    MACROS
+***************************************************************************/
+
+#define EARLY_EXIT(x)				do { (void)(x); goto cleanup; } while (0)
+
+/***************************************************************************
+    TYPE DEFINITIONS
+***************************************************************************/
+
+/* interface to a codec */
+typedef struct _codec_interface codec_interface;
+struct _codec_interface
+{
+	UINT32		compression;								/* type of compression */
+	const char *compname;									/* name of the algorithm */
+	UINT8		lossy;										/* is this a lossy algorithm? */
+	chd_error	(*init)(void *codec, UINT32 hunkbytes);		/* codec initialize */
+	void		(*free)(void *codec);						/* codec free */
+	chd_error	(*decompress)(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen); /* decompress data */
+	chd_error	(*config)(void *codec, int param, void *config); /* configure */
+};
+
+/* a single map entry */
+typedef struct _map_entry map_entry;
+struct _map_entry
+{
+	UINT64					offset;			/* offset within the file of the data */
+	UINT32					crc;			/* 32-bit CRC of the data */
+	UINT32					length;			/* length of the data */
+	UINT8					flags;			/* misc flags */
+};
+
+/* a single metadata entry */
+typedef struct _metadata_entry metadata_entry;
+struct _metadata_entry
+{
+	UINT64					offset;			/* offset within the file of the header */
+	UINT64					next;			/* offset within the file of the next header */
+	UINT64					prev;			/* offset within the file of the previous header */
+	UINT32					length;			/* length of the metadata */
+	UINT32					metatag;		/* metadata tag */
+	UINT8					flags;			/* flag bits */
+};
+
+/* codec-private data for the ZLIB codec */
+
+typedef struct _zlib_allocator zlib_allocator;
+struct _zlib_allocator
+{
+	UINT32 *				allocptr[MAX_ZLIB_ALLOCS];
+	UINT32 *				allocptr2[MAX_ZLIB_ALLOCS];
+};
+
+typedef struct _zlib_codec_data zlib_codec_data;
+struct _zlib_codec_data
+{
+	z_stream				inflater;
+	zlib_allocator			allocator;
+};
+
+/* codec-private data for the LZMA codec */
+#define MAX_LZMA_ALLOCS 64
+
+typedef struct _lzma_allocator lzma_allocator;
+struct _lzma_allocator
+{
+	void *(*Alloc)(void *p, size_t size);
+ 	void (*Free)(void *p, void *address); /* address can be 0 */
+	void (*FreeSz)(void *p, void *address, size_t size); /* address can be 0 */
+	uint32_t*	allocptr[MAX_LZMA_ALLOCS];
+	uint32_t*	allocptr2[MAX_LZMA_ALLOCS];
+};
+
+typedef struct _lzma_codec_data lzma_codec_data;
+struct _lzma_codec_data
+{
+	CLzmaDec		decoder;
+	lzma_allocator	allocator;
+};
+
+/* codec-private data for the CDZL codec */
+typedef struct _cdzl_codec_data cdzl_codec_data;
+struct _cdzl_codec_data {
+	/* internal state */
+	zlib_codec_data		base_decompressor;
+#ifdef WANT_SUBCODE
+	zlib_codec_data		subcode_decompressor;
+#endif
+	uint8_t*			buffer;
+};
+
+/* codec-private data for the CDLZ codec */
+typedef struct _cdlz_codec_data cdlz_codec_data;
+struct _cdlz_codec_data {
+	/* internal state */
+	lzma_codec_data		base_decompressor;
+#ifdef WANT_SUBCODE
+	zlib_codec_data		subcode_decompressor;
+#endif
+	uint8_t*			buffer;
+};
+
+/* codec-private data for the CDFL codec */
+typedef struct _cdfl_codec_data cdfl_codec_data;
+struct _cdfl_codec_data {
+	/* internal state */
+	int		swap_endian;
+	flac_decoder	decoder;
+#ifdef WANT_SUBCODE
+	zlib_codec_data		subcode_decompressor;
+#endif
+	uint8_t*	buffer;
+};
+
+/* internal representation of an open CHD file */
+struct _chd_file
+{
+	UINT32					cookie;			/* cookie, should equal COOKIE_VALUE */
+
+	core_file *				file;			/* handle to the open core file */
+	UINT8					owns_file;		/* flag indicating if this file should be closed on chd_close() */
+	chd_header				header;			/* header, extracted from file */
+
+	chd_file *				parent;			/* pointer to parent file, or NULL */
+
+	map_entry *				map;			/* array of map entries */
+
+#ifdef NEED_CACHE_HUNK
+	UINT8 *					cache;			/* hunk cache pointer */
+	UINT32					cachehunk;		/* index of currently cached hunk */
+
+	UINT8 *					compare;		/* hunk compare pointer */
+	UINT32					comparehunk;	/* index of current compare data */
+#endif
+
+	UINT8 *					compressed;		/* pointer to buffer for compressed data */
+	const codec_interface *	codecintf[4];	/* interface to the codec */
+
+	zlib_codec_data			zlib_codec_data;		/* zlib codec data */
+	cdzl_codec_data			cdzl_codec_data;		/* cdzl codec data */
+	cdlz_codec_data			cdlz_codec_data;		/* cdlz codec data */
+	cdfl_codec_data			cdfl_codec_data;		/* cdfl codec data */
+
+#ifdef NEED_CACHE_HUNK
+	UINT32					maxhunk;		/* maximum hunk accessed */
+#endif
+
+	UINT8 *					file_cache;		/* cache of underlying file */
+};
+
+
+/***************************************************************************
+    GLOBAL VARIABLES
+***************************************************************************/
+
+static const UINT8 nullmd5[CHD_MD5_BYTES] = { 0 };
+static const UINT8 nullsha1[CHD_SHA1_BYTES] = { 0 };
+
+/***************************************************************************
+    PROTOTYPES
+***************************************************************************/
+
+/* internal header operations */
+static chd_error header_validate(const chd_header *header);
+static chd_error header_read(chd_file *chd, chd_header *header);
+
+/* internal hunk read/write */
+#ifdef NEED_CACHE_HUNK
+static chd_error hunk_read_into_cache(chd_file *chd, UINT32 hunknum);
+#endif
+static chd_error hunk_read_into_memory(chd_file *chd, UINT32 hunknum, UINT8 *dest);
+
+/* internal map access */
+static chd_error map_read(chd_file *chd);
+
+/* metadata management */
+static chd_error metadata_find_entry(chd_file *chd, UINT32 metatag, UINT32 metaindex, metadata_entry *metaentry);
+
+/* zlib compression codec */
+static chd_error zlib_codec_init(void *codec, uint32_t hunkbytes);
+static void zlib_codec_free(void *codec);
+static chd_error zlib_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen);
+static voidpf zlib_fast_alloc(voidpf opaque, uInt items, uInt size);
+static void zlib_fast_free(voidpf opaque, voidpf address);
+static void zlib_allocator_free(voidpf opaque);
+
+/* lzma compression codec */
+static chd_error lzma_codec_init(void *codec, uint32_t hunkbytes);
+static void lzma_codec_free(void *codec);
+static chd_error lzma_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen);
+
+/* cdzl compression codec */
+static chd_error cdzl_codec_init(void* codec, uint32_t hunkbytes);
+static void cdzl_codec_free(void* codec);
+static chd_error cdzl_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen);
+
+/* cdlz compression codec */
+static chd_error cdlz_codec_init(void* codec, uint32_t hunkbytes);
+static void cdlz_codec_free(void* codec);
+static chd_error cdlz_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen);
+
+/* cdfl compression codec */
+static chd_error cdfl_codec_init(void* codec, uint32_t hunkbytes);
+static void cdfl_codec_free(void* codec);
+static chd_error cdfl_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen);
+
+/***************************************************************************
+ *  LZMA ALLOCATOR HELPER
+ ***************************************************************************
+ */
+
+static void *lzma_fast_alloc(void *p, size_t size);
+static void lzma_fast_free(void *p, void *address);
+
+/*-------------------------------------------------
+ *  lzma_allocator_init
+ *-------------------------------------------------
+ */
+
+static void lzma_allocator_init(void* p)
+{
+	lzma_allocator *codec = (lzma_allocator *)(p);
+
+	/* reset pointer list */
+	memset(codec->allocptr, 0, sizeof(codec->allocptr));
+	memset(codec->allocptr2, 0, sizeof(codec->allocptr2));
+	codec->Alloc = lzma_fast_alloc;
+	codec->Free = lzma_fast_free;
+}
+
+/*-------------------------------------------------
+ *  lzma_allocator_free
+ *-------------------------------------------------
+ */
+
+static void lzma_allocator_free(void* p )
+{
+	int i;
+	lzma_allocator *codec = (lzma_allocator *)(p);
+
+	/* free our memory */
+	for (i = 0 ; i < MAX_LZMA_ALLOCS ; i++)
+	{
+		if (codec->allocptr[i] != NULL)
+			free(codec->allocptr[i]);
+	}
+}
+
+/*-------------------------------------------------
+ *  lzma_fast_alloc - fast malloc for lzma, which
+ *  allocates and frees memory frequently
+ *-------------------------------------------------
+ */
+
+/* Huge alignment values for possible SIMD optimization by compiler (NEON, SSE, AVX) */
+#define LZMA_MIN_ALIGNMENT_BITS 512
+#define LZMA_MIN_ALIGNMENT_BYTES (LZMA_MIN_ALIGNMENT_BITS / 8)
+
+static void *lzma_fast_alloc(void *p, size_t size)
+{
+	int scan;
+	uint32_t *addr        = NULL;
+	lzma_allocator *codec = (lzma_allocator *)(p);
+	uintptr_t vaddr = 0;
+
+	/* compute the size, rounding to the nearest 1k */
+	size = (size + 0x3ff) & ~0x3ff;
+
+	/* reuse a hunk if we can */
+	for (scan = 0; scan < MAX_LZMA_ALLOCS; scan++)
+	{
+		uint32_t *ptr = codec->allocptr[scan];
+		if (ptr != NULL && size == *ptr)
+		{
+			/* set the low bit of the size so we don't match next time */
+			*ptr |= 1;
+
+			/* return aligned address of the block */
+			return codec->allocptr2[scan];
+		}
+	}
+
+	/* alloc a new one and put it into the list */
+	addr = (uint32_t *)malloc(size + sizeof(uint32_t) + LZMA_MIN_ALIGNMENT_BYTES);
+	if (addr==NULL)
+		return NULL;
+	for (scan = 0; scan < MAX_LZMA_ALLOCS; scan++)
+	{
+		if (codec->allocptr[scan] == NULL)
+		{
+			/* store block address */
+			codec->allocptr[scan] = addr;
+
+			/* compute aligned address, store it */
+			vaddr = (uintptr_t)addr;
+			vaddr = (vaddr + sizeof(uint32_t) + (LZMA_MIN_ALIGNMENT_BYTES-1)) & (~(LZMA_MIN_ALIGNMENT_BYTES-1));
+			codec->allocptr2[scan] = (uint32_t*)vaddr;
+			break;
+		}
+	}
+
+	/* set the low bit of the size so we don't match next time */
+	*addr = size | 1;
+
+	/* return aligned address */
+	return (void*)vaddr;
+}
+
+/*-------------------------------------------------
+ *  lzma_fast_free - fast free for lzma, which
+ *  allocates and frees memory frequently
+ *-------------------------------------------------
+ */
+
+static void lzma_fast_free(void *p, void *address)
+{
+	int scan;
+	uint32_t *ptr = NULL;
+	lzma_allocator *codec = NULL;
+
+	if (address == NULL)
+		return;
+
+	codec = (lzma_allocator *)(p);
+
+	/* find the hunk */
+	ptr = (uint32_t *)address;
+	for (scan = 0; scan < MAX_LZMA_ALLOCS; scan++)
+	{
+		if (ptr == codec->allocptr2[scan])
+		{
+			/* clear the low bit of the size to allow matches */
+			*codec->allocptr[scan] &= ~1;
+			return;
+		}
+	}
+}
+
+/***************************************************************************
+ *  LZMA DECOMPRESSOR
+ ***************************************************************************
+ */
+
+/*-------------------------------------------------
+ *  lzma_codec_init - constructor
+ *-------------------------------------------------
+ */
+
+static chd_error lzma_codec_init(void* codec, uint32_t hunkbytes)
+{
+	CLzmaEncHandle enc;
+	CLzmaEncProps encoder_props;
+	Byte decoder_props[LZMA_PROPS_SIZE];
+	SizeT props_size;
+	lzma_allocator* alloc;
+	lzma_codec_data* lzma_codec = (lzma_codec_data*) codec;
+
+	/* construct the decoder */
+	LzmaDec_Construct(&lzma_codec->decoder);
+
+	/* FIXME: this code is written in a way that makes it impossible to safely upgrade the LZMA SDK
+	 * This code assumes that the current version of the encoder imposes the same requirements on the
+	 * decoder as the encoder used to produce the file.  This is not necessarily true.  The format
+	 * needs to be changed so the encoder properties are written to the file.
+
+	 * configure the properties like the compressor did */
+	LzmaEncProps_Init(&encoder_props);
+	encoder_props.level = 9;
+	encoder_props.reduceSize = hunkbytes;
+	LzmaEncProps_Normalize(&encoder_props);
+
+	/* convert to decoder properties */
+	alloc = &lzma_codec->allocator;
+	lzma_allocator_init(alloc);
+	enc = LzmaEnc_Create((ISzAlloc*)alloc);
+	if (!enc)
+		return CHDERR_DECOMPRESSION_ERROR;
+	if (LzmaEnc_SetProps(enc, &encoder_props) != SZ_OK)
+	{
+		LzmaEnc_Destroy(enc, (ISzAlloc*)&alloc, (ISzAlloc*)&alloc);
+		return CHDERR_DECOMPRESSION_ERROR;
+	}
+	props_size = sizeof(decoder_props);
+	if (LzmaEnc_WriteProperties(enc, decoder_props, &props_size) != SZ_OK)
+	{
+		LzmaEnc_Destroy(enc, (ISzAlloc*)alloc, (ISzAlloc*)alloc);
+		return CHDERR_DECOMPRESSION_ERROR;
+	}
+	LzmaEnc_Destroy(enc, (ISzAlloc*)alloc, (ISzAlloc*)alloc);
+
+	/* do memory allocations */
+	if (LzmaDec_Allocate(&lzma_codec->decoder, decoder_props, LZMA_PROPS_SIZE, (ISzAlloc*)alloc) != SZ_OK)
+		return CHDERR_DECOMPRESSION_ERROR;
+
+	/* Okay */
+	return CHDERR_NONE;
+}
+
+/*-------------------------------------------------
+ *  lzma_codec_free
+ *-------------------------------------------------
+ */
+
+static void lzma_codec_free(void* codec)
+{
+	lzma_codec_data* lzma_codec = (lzma_codec_data*) codec;
+
+	/* free memory */
+	LzmaDec_Free(&lzma_codec->decoder, (ISzAlloc*)&lzma_codec->allocator);
+	lzma_allocator_free(&lzma_codec->allocator);
+}
+
+/*-------------------------------------------------
+ *  decompress - decompress data using the LZMA
+ *  codec
+ *-------------------------------------------------
+ */
+
+static chd_error lzma_codec_decompress(void* codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen)
+{
+	ELzmaStatus status;
+	SRes res;
+	SizeT consumedlen, decodedlen;
+	/* initialize */
+	lzma_codec_data* lzma_codec = (lzma_codec_data*) codec;
+	LzmaDec_Init(&lzma_codec->decoder);
+
+	/* decode */
+	consumedlen = complen;
+	decodedlen = destlen;
+	res = LzmaDec_DecodeToBuf(&lzma_codec->decoder, dest, &decodedlen, src, &consumedlen, LZMA_FINISH_END, &status);
+	if ((res != SZ_OK && res != LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK) || consumedlen != complen || decodedlen != destlen)
+		return CHDERR_DECOMPRESSION_ERROR;
+	return CHDERR_NONE;
+}
+
+/* cdlz */
+static chd_error cdlz_codec_init(void* codec, uint32_t hunkbytes)
+{
+	chd_error ret;
+	cdlz_codec_data* cdlz = (cdlz_codec_data*) codec;
+
+	/* allocate buffer */
+	cdlz->buffer = (uint8_t*)malloc(sizeof(uint8_t) * hunkbytes);
+	if (cdlz->buffer == NULL)
+		return CHDERR_OUT_OF_MEMORY;
+
+	/* make sure the CHD's hunk size is an even multiple of the frame size */
+	ret = lzma_codec_init(&cdlz->base_decompressor, (hunkbytes / CD_FRAME_SIZE) * CD_MAX_SECTOR_DATA);
+	if (ret != CHDERR_NONE)
+		return ret;
+
+#ifdef WANT_SUBCODE
+	ret = zlib_codec_init(&cdlz->subcode_decompressor, (hunkbytes / CD_FRAME_SIZE) * CD_MAX_SUBCODE_DATA);
+	if (ret != CHDERR_NONE)
+		return ret;
+#endif
+
+	if (hunkbytes % CD_FRAME_SIZE != 0)
+		return CHDERR_CODEC_ERROR;
+
+	return CHDERR_NONE;
+}
+
+static void cdlz_codec_free(void* codec)
+{
+	cdlz_codec_data* cdlz = (cdlz_codec_data*) codec;
+	free(cdlz->buffer);
+	lzma_codec_free(&cdlz->base_decompressor);
+#ifdef WANT_SUBCODE
+	zlib_codec_free(&cdlz->subcode_decompressor);
+#endif
+}
+
+static chd_error cdlz_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen)
+{
+	uint32_t framenum;
+	cdlz_codec_data* cdlz = (cdlz_codec_data*)codec;
+
+	/* determine header bytes */
+	uint32_t frames = destlen / CD_FRAME_SIZE;
+	uint32_t complen_bytes = (destlen < 65536) ? 2 : 3;
+	uint32_t ecc_bytes = (frames + 7) / 8;
+	uint32_t header_bytes = ecc_bytes + complen_bytes;
+
+	/* extract compressed length of base */
+	uint32_t complen_base = (src[ecc_bytes + 0] << 8) | src[ecc_bytes + 1];
+	if (complen_bytes > 2)
+		complen_base = (complen_base << 8) | src[ecc_bytes + 2];
+
+	/* reset and decode */
+	lzma_codec_decompress(&cdlz->base_decompressor, &src[header_bytes], complen_base, &cdlz->buffer[0], frames * CD_MAX_SECTOR_DATA);
+#ifdef WANT_SUBCODE
+	zlib_codec_decompress(&cdlz->subcode_decompressor, &src[header_bytes + complen_base], complen - complen_base - header_bytes, &cdlz->buffer[frames * CD_MAX_SECTOR_DATA], frames * CD_MAX_SUBCODE_DATA);
+#endif
+
+	/* reassemble the data */
+	for (framenum = 0; framenum < frames; framenum++)
+	{
+		uint8_t *sector;
+
+		memcpy(&dest[framenum * CD_FRAME_SIZE], &cdlz->buffer[framenum * CD_MAX_SECTOR_DATA], CD_MAX_SECTOR_DATA);
+#ifdef WANT_SUBCODE
+		memcpy(&dest[framenum * CD_FRAME_SIZE + CD_MAX_SECTOR_DATA], &cdlz->buffer[frames * CD_MAX_SECTOR_DATA + framenum * CD_MAX_SUBCODE_DATA], CD_MAX_SUBCODE_DATA);
+#endif
+
+#ifdef WANT_RAW_DATA_SECTOR
+		/* reconstitute the ECC data and sync header */
+		sector = (uint8_t *)&dest[framenum * CD_FRAME_SIZE];
+		if ((src[framenum / 8] & (1 << (framenum % 8))) != 0)
+		{
+			memcpy(sector, s_cd_sync_header, sizeof(s_cd_sync_header));
+			ecc_generate(sector);
+		}
+#endif
+	}
+	return CHDERR_NONE;
+}
+
+/* cdzl */
+
+static chd_error cdzl_codec_init(void *codec, uint32_t hunkbytes)
+{
+	chd_error ret;
+	cdzl_codec_data* cdzl = (cdzl_codec_data*)codec;
+
+	/* make sure the CHD's hunk size is an even multiple of the frame size */
+	if (hunkbytes % CD_FRAME_SIZE != 0)
+		return CHDERR_CODEC_ERROR;
+
+	cdzl->buffer = (uint8_t*)malloc(sizeof(uint8_t) * hunkbytes);
+	if (cdzl->buffer == NULL)
+		return CHDERR_OUT_OF_MEMORY;
+
+	ret = zlib_codec_init(&cdzl->base_decompressor, (hunkbytes / CD_FRAME_SIZE) * CD_MAX_SECTOR_DATA);
+	if (ret != CHDERR_NONE)
+		return ret;
+
+#ifdef WANT_SUBCODE
+	ret = zlib_codec_init(&cdzl->subcode_decompressor, (hunkbytes / CD_FRAME_SIZE) * CD_MAX_SUBCODE_DATA);
+	if (ret != CHDERR_NONE)
+		return ret;
+#endif
+
+	return CHDERR_NONE;
+}
+
+static void cdzl_codec_free(void *codec)
+{
+	cdzl_codec_data* cdzl = (cdzl_codec_data*)codec;
+	zlib_codec_free(&cdzl->base_decompressor);
+#ifdef WANT_SUBCODE
+	zlib_codec_free(&cdzl->subcode_decompressor);
+#endif
+	free(cdzl->buffer);
+}
+
+static chd_error cdzl_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen)
+{
+	uint32_t framenum;
+	cdzl_codec_data* cdzl = (cdzl_codec_data*)codec;
+
+	/* determine header bytes */
+	uint32_t frames = destlen / CD_FRAME_SIZE;
+	uint32_t complen_bytes = (destlen < 65536) ? 2 : 3;
+	uint32_t ecc_bytes = (frames + 7) / 8;
+	uint32_t header_bytes = ecc_bytes + complen_bytes;
+
+	/* extract compressed length of base */
+	uint32_t complen_base = (src[ecc_bytes + 0] << 8) | src[ecc_bytes + 1];
+	if (complen_bytes > 2)
+		complen_base = (complen_base << 8) | src[ecc_bytes + 2];
+
+	/* reset and decode */
+	zlib_codec_decompress(&cdzl->base_decompressor, &src[header_bytes], complen_base, &cdzl->buffer[0], frames * CD_MAX_SECTOR_DATA);
+#ifdef WANT_SUBCODE
+	zlib_codec_decompress(&cdzl->subcode_decompressor, &src[header_bytes + complen_base], complen - complen_base - header_bytes, &cdzl->buffer[frames * CD_MAX_SECTOR_DATA], frames * CD_MAX_SUBCODE_DATA);
+#endif
+
+	/* reassemble the data */
+	for (framenum = 0; framenum < frames; framenum++)
+	{
+		uint8_t *sector;
+
+		memcpy(&dest[framenum * CD_FRAME_SIZE], &cdzl->buffer[framenum * CD_MAX_SECTOR_DATA], CD_MAX_SECTOR_DATA);
+#ifdef WANT_SUBCODE
+		memcpy(&dest[framenum * CD_FRAME_SIZE + CD_MAX_SECTOR_DATA], &cdzl->buffer[frames * CD_MAX_SECTOR_DATA + framenum * CD_MAX_SUBCODE_DATA], CD_MAX_SUBCODE_DATA);
+#endif
+
+#ifdef WANT_RAW_DATA_SECTOR
+		/* reconstitute the ECC data and sync header */
+		sector = (uint8_t *)&dest[framenum * CD_FRAME_SIZE];
+		if ((src[framenum / 8] & (1 << (framenum % 8))) != 0)
+		{
+			memcpy(sector, s_cd_sync_header, sizeof(s_cd_sync_header));
+			ecc_generate(sector);
+		}
+#endif
+	}
+	return CHDERR_NONE;
+}
+
+/***************************************************************************
+ *  CD FLAC DECOMPRESSOR
+ ***************************************************************************
+ */
+
+/*------------------------------------------------------
+ *  cdfl_codec_blocksize - return the optimal block size
+ *------------------------------------------------------
+ */
+
+static uint32_t cdfl_codec_blocksize(uint32_t bytes)
+{
+	/* determine FLAC block size, which must be 16-65535
+	 * clamp to 2k since that's supposed to be the sweet spot */
+	uint32_t hunkbytes = bytes / 4;
+	while (hunkbytes > 2048)
+		hunkbytes /= 2;
+	return hunkbytes;
+}
+
+static chd_error cdfl_codec_init(void *codec, uint32_t hunkbytes)
+{
+#ifdef WANT_SUBCODE
+	chd_error ret;
+#endif
+	uint16_t native_endian = 0;
+	cdfl_codec_data *cdfl = (cdfl_codec_data*)codec;
+
+	/* make sure the CHD's hunk size is an even multiple of the frame size */
+	if (hunkbytes % CD_FRAME_SIZE != 0)
+		return CHDERR_CODEC_ERROR;
+
+	cdfl->buffer = (uint8_t*)malloc(sizeof(uint8_t) * hunkbytes);
+	if (cdfl->buffer == NULL)
+		return CHDERR_OUT_OF_MEMORY;
+
+	/* determine whether we want native or swapped samples */
+	*(uint8_t *)(&native_endian) = 1;
+	cdfl->swap_endian = (native_endian & 1);
+
+#ifdef WANT_SUBCODE
+	/* init zlib inflater */
+	ret = zlib_codec_init(&cdfl->subcode_decompressor, (hunkbytes / CD_FRAME_SIZE) * CD_MAX_SECTOR_DATA);
+	if (ret != CHDERR_NONE)
+		return ret;
+#endif
+
+	/* flac decoder init */
+	if (flac_decoder_init(&cdfl->decoder))
+		return CHDERR_OUT_OF_MEMORY;
+
+	return CHDERR_NONE;
+}
+
+static void cdfl_codec_free(void *codec)
+{
+	cdfl_codec_data *cdfl = (cdfl_codec_data*)codec;
+	flac_decoder_free(&cdfl->decoder);
+#ifdef WANT_SUBCODE
+	zlib_codec_free(&cdfl->subcode_decompressor);
+#endif
+	if (cdfl->buffer)
+		free(cdfl->buffer);
+}
+
+static chd_error cdfl_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen)
+{
+	uint32_t framenum;
+	uint8_t *buffer;
+#ifdef WANT_SUBCODE
+	uint32_t offset;
+	chd_error ret;
+#endif
+	cdfl_codec_data *cdfl = (cdfl_codec_data*)codec;
+
+	/* reset and decode */
+	uint32_t frames = destlen / CD_FRAME_SIZE;
+
+	if (!flac_decoder_reset(&cdfl->decoder, 44100, 2, cdfl_codec_blocksize(frames * CD_MAX_SECTOR_DATA), src, complen))
+		return CHDERR_DECOMPRESSION_ERROR;
+	buffer = &cdfl->buffer[0];
+	if (!flac_decoder_decode_interleaved(&cdfl->decoder, (int16_t *)(buffer), frames * CD_MAX_SECTOR_DATA/4, cdfl->swap_endian))
+		return CHDERR_DECOMPRESSION_ERROR;
+
+#ifdef WANT_SUBCODE
+	/* inflate the subcode data */
+	offset = flac_decoder_finish(&cdfl->decoder);
+	ret = zlib_codec_decompress(&cdfl->subcode_decompressor, src + offset, complen - offset, &cdfl->buffer[frames * CD_MAX_SECTOR_DATA], frames * CD_MAX_SUBCODE_DATA);
+	if (ret != CHDERR_NONE)
+		return ret;
+#else
+	flac_decoder_finish(&cdfl->decoder);
+#endif
+
+	/* reassemble the data */
+	for (framenum = 0; framenum < frames; framenum++)
+	{
+		memcpy(&dest[framenum * CD_FRAME_SIZE], &cdfl->buffer[framenum * CD_MAX_SECTOR_DATA], CD_MAX_SECTOR_DATA);
+#ifdef WANT_SUBCODE
+		memcpy(&dest[framenum * CD_FRAME_SIZE + CD_MAX_SECTOR_DATA], &cdfl->buffer[frames * CD_MAX_SECTOR_DATA + framenum * CD_MAX_SUBCODE_DATA], CD_MAX_SUBCODE_DATA);
+#endif
+	}
+
+	return CHDERR_NONE;
+}
+/***************************************************************************
+    CODEC INTERFACES
+***************************************************************************/
+
+static const codec_interface codec_interfaces[] =
+{
+	/* "none" or no compression */
+	{
+		CHDCOMPRESSION_NONE,
+		"none",
+		FALSE,
+		NULL,
+		NULL,
+		NULL,
+		NULL
+	},
+
+	/* standard zlib compression */
+	{
+		CHDCOMPRESSION_ZLIB,
+		"zlib",
+		FALSE,
+		zlib_codec_init,
+		zlib_codec_free,
+		zlib_codec_decompress,
+		NULL
+	},
+
+	/* zlib+ compression */
+	{
+		CHDCOMPRESSION_ZLIB_PLUS,
+		"zlib+",
+		FALSE,
+		zlib_codec_init,
+		zlib_codec_free,
+		zlib_codec_decompress,
+		NULL
+	},
+
+	/* V5 zlib compression */
+	{
+		CHD_CODEC_ZLIB,
+		"zlib (Deflate)",
+		FALSE,
+		zlib_codec_init,
+		zlib_codec_free,
+		zlib_codec_decompress,
+		NULL
+	},
+
+	/* V5 CD zlib compression */
+	{
+		CHD_CODEC_CD_ZLIB,
+		"cdzl (CD Deflate)",
+		FALSE,
+		cdzl_codec_init,
+		cdzl_codec_free,
+		cdzl_codec_decompress,
+		NULL
+	},
+
+	/* V5 CD lzma compression */
+	{
+		CHD_CODEC_CD_LZMA,
+		"cdlz (CD LZMA)",
+		FALSE,
+		cdlz_codec_init,
+		cdlz_codec_free,
+		cdlz_codec_decompress,
+		NULL
+	},
+
+	/* V5 CD flac compression */
+	{
+		CHD_CODEC_CD_FLAC,
+		"cdfl (CD FLAC)",
+		FALSE,
+		cdfl_codec_init,
+		cdfl_codec_free,
+		cdfl_codec_decompress,
+		NULL
+	},
+};
+
+/***************************************************************************
+    INLINE FUNCTIONS
+***************************************************************************/
+
+/*-------------------------------------------------
+    get_bigendian_uint64 - fetch a UINT64 from
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline UINT64 get_bigendian_uint64(const UINT8 *base)
+{
+	return ((UINT64)base[0] << 56) | ((UINT64)base[1] << 48) | ((UINT64)base[2] << 40) | ((UINT64)base[3] << 32) |
+			((UINT64)base[4] << 24) | ((UINT64)base[5] << 16) | ((UINT64)base[6] << 8) | (UINT64)base[7];
+}
+
+/*-------------------------------------------------
+    put_bigendian_uint64 - write a UINT64 to
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline void put_bigendian_uint64(UINT8 *base, UINT64 value)
+{
+	base[0] = value >> 56;
+	base[1] = value >> 48;
+	base[2] = value >> 40;
+	base[3] = value >> 32;
+	base[4] = value >> 24;
+	base[5] = value >> 16;
+	base[6] = value >> 8;
+	base[7] = value;
+}
+
+/*-------------------------------------------------
+    get_bigendian_uint48 - fetch a UINT48 from
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline UINT64 get_bigendian_uint48(const UINT8 *base)
+{
+	return  ((UINT64)base[0] << 40) | ((UINT64)base[1] << 32) |
+			((UINT64)base[2] << 24) | ((UINT64)base[3] << 16) | ((UINT64)base[4] << 8) | (UINT64)base[5];
+}
+
+/*-------------------------------------------------
+    put_bigendian_uint48 - write a UINT48 to
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline void put_bigendian_uint48(UINT8 *base, UINT64 value)
+{
+	value &= 0xffffffffffff;
+	base[0] = value >> 40;
+	base[1] = value >> 32;
+	base[2] = value >> 24;
+	base[3] = value >> 16;
+	base[4] = value >> 8;
+	base[5] = value;
+}
+/*-------------------------------------------------
+    get_bigendian_uint32 - fetch a UINT32 from
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline UINT32 get_bigendian_uint32(const UINT8 *base)
+{
+	return (base[0] << 24) | (base[1] << 16) | (base[2] << 8) | base[3];
+}
+
+/*-------------------------------------------------
+    put_bigendian_uint32 - write a UINT32 to
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline void put_bigendian_uint32(UINT8 *base, UINT32 value)
+{
+	base[0] = value >> 24;
+	base[1] = value >> 16;
+	base[2] = value >> 8;
+	base[3] = value;
+}
+
+/*-------------------------------------------------
+    put_bigendian_uint24 - write a UINT24 to
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline void put_bigendian_uint24(UINT8 *base, UINT32 value)
+{
+	value &= 0xffffff;
+	base[0] = value >> 16;
+	base[1] = value >> 8;
+	base[2] = value;
+}
+
+/*-------------------------------------------------
+    get_bigendian_uint24 - fetch a UINT24 from
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline UINT32 get_bigendian_uint24(const UINT8 *base)
+{
+	return (base[0] << 16) | (base[1] << 8) | base[2];
+}
+
+/*-------------------------------------------------
+    get_bigendian_uint16 - fetch a UINT16 from
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline UINT16 get_bigendian_uint16(const UINT8 *base)
+{
+	return (base[0] << 8) | base[1];
+}
+
+/*-------------------------------------------------
+    put_bigendian_uint16 - write a UINT16 to
+    the data stream in bigendian order
+-------------------------------------------------*/
+
+static inline void put_bigendian_uint16(UINT8 *base, UINT16 value)
+{
+	base[0] = value >> 8;
+	base[1] = value;
+}
+
+/*-------------------------------------------------
+    map_extract - extract a single map
+    entry from the datastream
+-------------------------------------------------*/
+
+static inline void map_extract(const UINT8 *base, map_entry *entry)
+{
+	entry->offset = get_bigendian_uint64(&base[0]);
+	entry->crc = get_bigendian_uint32(&base[8]);
+	entry->length = get_bigendian_uint16(&base[12]) | (base[14] << 16);
+	entry->flags = base[15];
+}
+
+/*-------------------------------------------------
+    map_assemble - write a single map
+    entry to the datastream
+-------------------------------------------------*/
+
+static inline void map_assemble(UINT8 *base, map_entry *entry)
+{
+	put_bigendian_uint64(&base[0], entry->offset);
+	put_bigendian_uint32(&base[8], entry->crc);
+	put_bigendian_uint16(&base[12], entry->length);
+	base[14] = entry->length >> 16;
+	base[15] = entry->flags;
+}
+
+/*-------------------------------------------------
+    map_size_v5 - calculate CHDv5 map size
+-------------------------------------------------*/
+static inline int map_size_v5(chd_header* header)
+{
+	return header->hunkcount * header->mapentrybytes;
+}
+
+/*-------------------------------------------------
+    crc16 - calculate CRC16 (from hashing.cpp)
+-------------------------------------------------*/
+uint16_t crc16(const void *data, uint32_t length)
+{
+	uint16_t crc = 0xffff;
+
+	static const uint16_t s_table[256] =
+	{
+		0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
+		0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
+		0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
+		0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
+		0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
+		0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
+		0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
+		0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
+		0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
+		0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
+		0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
+		0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
+		0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
+		0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
+		0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
+		0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
+		0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
+		0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
+		0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
+		0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
+		0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
+		0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
+		0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
+		0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
+		0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
+		0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
+		0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
+		0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
+		0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
+		0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
+		0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
+		0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
+	};
+
+	const uint8_t *src = (uint8_t*)data;
+
+	/* fetch the current value into a local and rip through the source data */
+	while (length-- != 0)
+		crc = (crc << 8) ^ s_table[(crc >> 8) ^ *src++];
+	return crc;
+}
+
+/*-------------------------------------------------
+	compressed - test if CHD file is compressed
++-------------------------------------------------*/
+static inline int chd_compressed(chd_header* header) {
+	return header->compression[0] != CHD_CODEC_NONE;
+}
+
+/*-------------------------------------------------
+	decompress_v5_map - decompress the v5 map
+-------------------------------------------------*/
+
+static chd_error decompress_v5_map(chd_file* chd, chd_header* header)
+{
+	int result = 0;
+	int hunknum;
+	int repcount = 0;
+	uint8_t lastcomp = 0;
+	uint32_t last_self = 0;
+	uint64_t last_parent = 0;
+	struct bitstream* bitbuf;
+	uint32_t mapbytes;
+	uint64_t firstoffs;
+	uint16_t mapcrc;
+	uint8_t lengthbits;
+	uint8_t selfbits;
+	uint8_t parentbits;
+	uint8_t *compressed_ptr;
+	uint8_t rawbuf[16];
+	struct huffman_decoder* decoder;
+	enum huffman_error err;
+	uint64_t curoffset;	
+	int rawmapsize = map_size_v5(header);
+
+	if (!chd_compressed(header))
+	{
+		header->rawmap = (uint8_t*)malloc(rawmapsize);
+		core_fseek(chd->file, header->mapoffset, SEEK_SET);
+		result = core_fread(chd->file, header->rawmap, rawmapsize);
+		return CHDERR_NONE;
+	}
+
+	/* read the reader */
+	core_fseek(chd->file, header->mapoffset, SEEK_SET);
+	result = core_fread(chd->file, rawbuf, sizeof(rawbuf));
+	mapbytes = get_bigendian_uint32(&rawbuf[0]);
+	firstoffs = get_bigendian_uint48(&rawbuf[4]);
+	mapcrc = get_bigendian_uint16(&rawbuf[10]);
+	lengthbits = rawbuf[12];
+	selfbits = rawbuf[13];
+	parentbits = rawbuf[14];
+
+	/* now read the map */
+	compressed_ptr = (uint8_t*)malloc(sizeof(uint8_t) * mapbytes);
+	core_fseek(chd->file, header->mapoffset + 16, SEEK_SET);
+	result = core_fread(chd->file, compressed_ptr, mapbytes);
+	bitbuf = create_bitstream(compressed_ptr, sizeof(uint8_t) * mapbytes);
+	header->rawmap = (uint8_t*)malloc(rawmapsize);
+
+	/* first decode the compression types */
+	decoder = create_huffman_decoder(16, 8);
+	if (decoder == NULL)
+	{
+		free(compressed_ptr);
+		free(bitbuf);
+		return CHDERR_OUT_OF_MEMORY;
+	}
+
+	err = huffman_import_tree_rle(decoder, bitbuf);
+	if (err != HUFFERR_NONE)
+	{
+		free(compressed_ptr);
+		free(bitbuf);
+		delete_huffman_decoder(decoder);
+		return CHDERR_DECOMPRESSION_ERROR;
+	}
+
+	for (hunknum = 0; hunknum < header->hunkcount; hunknum++)
+	{
+		uint8_t *rawmap = header->rawmap + (hunknum * 12);
+		if (repcount > 0)
+			rawmap[0] = lastcomp, repcount--;
+		else
+		{
+			uint8_t val = huffman_decode_one(decoder, bitbuf);
+			if (val == COMPRESSION_RLE_SMALL)
+				rawmap[0] = lastcomp, repcount = 2 + huffman_decode_one(decoder, bitbuf);
+			else if (val == COMPRESSION_RLE_LARGE)
+				rawmap[0] = lastcomp, repcount = 2 + 16 + (huffman_decode_one(decoder, bitbuf) << 4), repcount += huffman_decode_one(decoder, bitbuf);
+			else
+				rawmap[0] = lastcomp = val;
+		}
+	}
+
+	/* then iterate through the hunks and extract the needed data */
+	curoffset = firstoffs;
+	for (hunknum = 0; hunknum < header->hunkcount; hunknum++)
+	{
+		uint8_t *rawmap = header->rawmap + (hunknum * 12);
+		uint64_t offset = curoffset;
+		uint32_t length = 0;
+		uint16_t crc = 0;
+		switch (rawmap[0])
+		{
+			/* base types */
+			case COMPRESSION_TYPE_0:
+			case COMPRESSION_TYPE_1:
+			case COMPRESSION_TYPE_2:
+			case COMPRESSION_TYPE_3:
+				curoffset += length = bitstream_read(bitbuf, lengthbits);
+				crc = bitstream_read(bitbuf, 16);
+				break;
+
+			case COMPRESSION_NONE:
+				curoffset += length = header->hunkbytes;
+				crc = bitstream_read(bitbuf, 16);
+				break;
+
+			case COMPRESSION_SELF:
+				last_self = offset = bitstream_read(bitbuf, selfbits);
+				break;
+
+			case COMPRESSION_PARENT:
+				offset = bitstream_read(bitbuf, parentbits);
+				last_parent = offset;
+				break;
+
+			/* pseudo-types; convert into base types */
+			case COMPRESSION_SELF_1:
+				last_self++;
+			case COMPRESSION_SELF_0:
+				rawmap[0] = COMPRESSION_SELF;
+				offset = last_self;
+				break;
+
+			case COMPRESSION_PARENT_SELF:
+				rawmap[0] = COMPRESSION_PARENT;
+				last_parent = offset = ( ((uint64_t)hunknum) * ((uint64_t)header->hunkbytes) ) / header->unitbytes;
+				break;
+
+			case COMPRESSION_PARENT_1:
+				last_parent += header->hunkbytes / header->unitbytes;
+			case COMPRESSION_PARENT_0:
+				rawmap[0] = COMPRESSION_PARENT;
+				offset = last_parent;
+				break;
+		}
+		/* UINT24 length */
+		put_bigendian_uint24(&rawmap[1], length);
+
+		/* UINT48 offset */
+		put_bigendian_uint48(&rawmap[4], offset);
+
+		/* crc16 */
+		put_bigendian_uint16(&rawmap[10], crc);
+	}
+
+	/* free memory */
+	free(compressed_ptr);
+	free(bitbuf);
+	delete_huffman_decoder(decoder);
+
+	/* verify the final CRC */
+	if (crc16(&header->rawmap[0], header->hunkcount * 12) != mapcrc)
+		return CHDERR_DECOMPRESSION_ERROR;
+
+	return CHDERR_NONE;
+}
+
+/*-------------------------------------------------
+    map_extract_old - extract a single map
+    entry in old format from the datastream
+-------------------------------------------------*/
+
+static inline void map_extract_old(const UINT8 *base, map_entry *entry, UINT32 hunkbytes)
+{
+	entry->offset = get_bigendian_uint64(&base[0]);
+	entry->crc = 0;
+	entry->length = entry->offset >> 44;
+	entry->flags = MAP_ENTRY_FLAG_NO_CRC | ((entry->length == hunkbytes) ? V34_MAP_ENTRY_TYPE_UNCOMPRESSED : V34_MAP_ENTRY_TYPE_COMPRESSED);
+#ifdef __MWERKS__
+	entry->offset = entry->offset & 0x00000FFFFFFFFFFFLL;
+#else
+	entry->offset = (entry->offset << 20) >> 20;
+#endif
+}
+
+/***************************************************************************
+    CHD FILE MANAGEMENT
+***************************************************************************/
+
+/*-------------------------------------------------
+    chd_open_file - open a CHD file for access
+-------------------------------------------------*/
+
+CHD_EXPORT chd_error chd_open_file(core_file *file, int mode, chd_file *parent, chd_file **chd)
+{
+	chd_file *newchd = NULL;
+	chd_error err;
+	int intfnum;
+
+	/* verify parameters */
+	if (file == NULL)
+		EARLY_EXIT(err = CHDERR_INVALID_PARAMETER);
+
+	/* punt if invalid parent */
+	if (parent != NULL && parent->cookie != COOKIE_VALUE)
+		EARLY_EXIT(err = CHDERR_INVALID_PARAMETER);
+
+	/* allocate memory for the final result */
+	newchd = (chd_file *)malloc(sizeof(**chd));
+	if (newchd == NULL)
+		EARLY_EXIT(err = CHDERR_OUT_OF_MEMORY);
+	memset(newchd, 0, sizeof(*newchd));
+	newchd->cookie = COOKIE_VALUE;
+	newchd->parent = parent;
+	newchd->file = file;
+
+	/* now attempt to read the header */
+	err = header_read(newchd, &newchd->header);
+	if (err != CHDERR_NONE)
+		EARLY_EXIT(err);
+
+	/* validate the header */
+	err = header_validate(&newchd->header);
+	if (err != CHDERR_NONE)
+		EARLY_EXIT(err);
+
+	/* make sure we don't open a read-only file writeable */
+	if (mode == CHD_OPEN_READWRITE && !(newchd->header.flags & CHDFLAGS_IS_WRITEABLE))
+		EARLY_EXIT(err = CHDERR_FILE_NOT_WRITEABLE);
+
+	/* also, never open an older version writeable */
+	if (mode == CHD_OPEN_READWRITE && newchd->header.version < CHD_HEADER_VERSION)
+		EARLY_EXIT(err = CHDERR_UNSUPPORTED_VERSION);
+
+	/* if we need a parent, make sure we have one */
+	if (parent == NULL && (newchd->header.flags & CHDFLAGS_HAS_PARENT))
+		EARLY_EXIT(err = CHDERR_REQUIRES_PARENT);
+
+	/* make sure we have a valid parent */
+	if (parent != NULL)
+	{
+		/* check MD5 if it isn't empty */
+		if (memcmp(nullmd5, newchd->header.parentmd5, sizeof(newchd->header.parentmd5)) != 0 &&
+			memcmp(nullmd5, newchd->parent->header.md5, sizeof(newchd->parent->header.md5)) != 0 &&
+			memcmp(newchd->parent->header.md5, newchd->header.parentmd5, sizeof(newchd->header.parentmd5)) != 0)
+			EARLY_EXIT(err = CHDERR_INVALID_PARENT);
+
+		/* check SHA1 if it isn't empty */
+		if (memcmp(nullsha1, newchd->header.parentsha1, sizeof(newchd->header.parentsha1)) != 0 &&
+			memcmp(nullsha1, newchd->parent->header.sha1, sizeof(newchd->parent->header.sha1)) != 0 &&
+			memcmp(newchd->parent->header.sha1, newchd->header.parentsha1, sizeof(newchd->header.parentsha1)) != 0)
+			EARLY_EXIT(err = CHDERR_INVALID_PARENT);
+	}
+
+	/* now read the hunk map */
+	if (newchd->header.version < 5)
+	{
+		err = map_read(newchd);
+		if (err != CHDERR_NONE)
+			EARLY_EXIT(err);
+	}
+	else
+	{
+		err = decompress_v5_map(newchd, &(newchd->header));
+	}
+	if (err != CHDERR_NONE)
+		EARLY_EXIT(err);
+
+#ifdef NEED_CACHE_HUNK
+	/* allocate and init the hunk cache */
+	newchd->cache = (UINT8 *)malloc(newchd->header.hunkbytes);
+	newchd->compare = (UINT8 *)malloc(newchd->header.hunkbytes);
+	if (newchd->cache == NULL || newchd->compare == NULL)
+		EARLY_EXIT(err = CHDERR_OUT_OF_MEMORY);
+	newchd->cachehunk = ~0;
+	newchd->comparehunk = ~0;
+#endif
+
+	/* allocate the temporary compressed buffer */
+	newchd->compressed = (UINT8 *)malloc(newchd->header.hunkbytes);
+	if (newchd->compressed == NULL)
+		EARLY_EXIT(err = CHDERR_OUT_OF_MEMORY);
+
+	/* find the codec interface */
+	if (newchd->header.version < 5)
+	{
+		for (intfnum = 0; intfnum < ARRAY_LENGTH(codec_interfaces); intfnum++)
+		{
+			if (codec_interfaces[intfnum].compression == newchd->header.compression[0])
+			{
+				newchd->codecintf[0] = &codec_interfaces[intfnum];
+				break;
+			}
+		}
+
+		if (intfnum == ARRAY_LENGTH(codec_interfaces))
+			EARLY_EXIT(err = CHDERR_UNSUPPORTED_FORMAT);
+
+		/* initialize the codec */
+		if (newchd->codecintf[0]->init != NULL)
+		{
+			err = (*newchd->codecintf[0]->init)(&newchd->zlib_codec_data, newchd->header.hunkbytes);
+			if (err != CHDERR_NONE)
+				EARLY_EXIT(err);
+		}
+	}
+	else
+	{
+		int decompnum;
+		/* verify the compression types and initialize the codecs */
+		for (decompnum = 0; decompnum < ARRAY_LENGTH(newchd->header.compression); decompnum++)
+		{
+			int i;
+			for (i = 0 ; i < ARRAY_LENGTH(codec_interfaces) ; i++)
+			{
+				if (codec_interfaces[i].compression == newchd->header.compression[decompnum])
+				{
+					newchd->codecintf[decompnum] = &codec_interfaces[i];
+					break;
+				}
+			}
+
+			if (newchd->codecintf[decompnum] == NULL && newchd->header.compression[decompnum] != 0)
+				EARLY_EXIT(err = CHDERR_UNSUPPORTED_FORMAT);
+
+			/* initialize the codec */
+			if (newchd->codecintf[decompnum]->init != NULL)
+			{
+				void* codec = NULL;
+				switch (newchd->header.compression[decompnum])
+				{
+					case CHD_CODEC_ZLIB:
+						codec = &newchd->zlib_codec_data;
+						break;
+
+					case CHD_CODEC_CD_ZLIB:
+						codec = &newchd->cdzl_codec_data;
+						break;
+
+					case CHD_CODEC_CD_LZMA:
+						codec = &newchd->cdlz_codec_data;
+						break;
+
+					case CHD_CODEC_CD_FLAC:
+						codec = &newchd->cdfl_codec_data;
+						break;
+				}
+
+				if (codec == NULL)
+					EARLY_EXIT(err = CHDERR_UNSUPPORTED_FORMAT);
+
+				err = (*newchd->codecintf[decompnum]->init)(codec, newchd->header.hunkbytes);
+				if (err != CHDERR_NONE)
+					EARLY_EXIT(err);
+			}
+		}
+	}
+
+	/* all done */
+	*chd = newchd;
+	return CHDERR_NONE;
+
+cleanup:
+	if (newchd != NULL)
+		chd_close(newchd);
+	return err;
+}
+
+/*-------------------------------------------------
+    chd_precache - precache underlying file in
+    memory
+-------------------------------------------------*/
+
+CHD_EXPORT chd_error chd_precache(chd_file *chd)
+{
+#ifdef _MSC_VER
+	size_t size, count;
+#else
+	ssize_t size, count;
+#endif
+
+	if (chd->file_cache == NULL)
+	{
+		core_fseek(chd->file, 0, SEEK_END);
+		size = core_ftell(chd->file);
+		if (size <= 0)
+			return CHDERR_INVALID_DATA;
+		chd->file_cache = malloc(size);
+		if (chd->file_cache == NULL)
+			return CHDERR_OUT_OF_MEMORY;
+		core_fseek(chd->file, 0, SEEK_SET);
+		count = core_fread(chd->file, chd->file_cache, size);
+		if (count != size)
+		{
+			free(chd->file_cache);
+			chd->file_cache = NULL;
+			return CHDERR_READ_ERROR;
+		}
+	}
+
+	return CHDERR_NONE;
+}
+
+/*-------------------------------------------------
+    chd_open - open a CHD file by
+    filename
+-------------------------------------------------*/
+
+CHD_EXPORT chd_error chd_open(const char *filename, int mode, chd_file *parent, chd_file **chd)
+{
+	chd_error err;
+	core_file *file = NULL;
+
+	/* choose the proper mode */
+	switch(mode)
+	{
+		case CHD_OPEN_READ:
+			break;
+
+		default:
+			err = CHDERR_INVALID_PARAMETER;
+			goto cleanup;
+	}
+
+	/* open the file */
+	file = core_fopen(filename);
+	if (file == 0)
+	{
+		err = CHDERR_FILE_NOT_FOUND;
+		goto cleanup;
+	}
+
+	/* now open the CHD */
+	err = chd_open_file(file, mode, parent, chd);
+	if (err != CHDERR_NONE)
+		goto cleanup;
+
+	/* we now own this file */
+	(*chd)->owns_file = TRUE;
+
+cleanup:
+	if ((err != CHDERR_NONE) && (file != NULL))
+		core_fclose(file);
+	return err;
+}
+
+/*-------------------------------------------------
+    chd_close - close a CHD file for access
+-------------------------------------------------*/
+
+CHD_EXPORT void chd_close(chd_file *chd)
+{
+	/* punt if NULL or invalid */
+	if (chd == NULL || chd->cookie != COOKIE_VALUE)
+		return;
+
+	/* deinit the codec */
+	if (chd->header.version < 5)
+	{
+		if (chd->codecintf[0] != NULL && chd->codecintf[0]->free != NULL)
+			(*chd->codecintf[0]->free)(&chd->zlib_codec_data);
+	}
+	else
+	{
+		int i;
+		/* Free the codecs */
+		for (i = 0 ; i < ARRAY_LENGTH(chd->codecintf); i++)
+		{
+			void* codec = NULL;
+
+			if (chd->codecintf[i] == NULL)
+				continue;
+
+			switch (chd->codecintf[i]->compression)
+			{
+				case CHD_CODEC_CD_LZMA:
+					codec = &chd->cdlz_codec_data;
+					break;
+
+				case CHD_CODEC_ZLIB:
+					codec = &chd->zlib_codec_data;
+					break;
+
+				case CHD_CODEC_CD_ZLIB:
+					codec = &chd->cdzl_codec_data;
+					break;
+
+				case CHD_CODEC_CD_FLAC:
+					codec = &chd->cdfl_codec_data;
+					break;
+			}
+
+			if (codec)
+			{
+				(*chd->codecintf[i]->free)(codec);
+			}
+		}
+
+		/* Free the raw map */
+		if (chd->header.rawmap != NULL)
+			free(chd->header.rawmap);
+	}
+
+	/* free the compressed data buffer */
+	if (chd->compressed != NULL)
+		free(chd->compressed);
+
+#ifdef NEED_CACHE_HUNK
+	/* free the hunk cache and compare data */
+	if (chd->compare != NULL)
+		free(chd->compare);
+	if (chd->cache != NULL)
+		free(chd->cache);
+#endif
+
+	/* free the hunk map */
+	if (chd->map != NULL)
+		free(chd->map);
+
+	/* close the file */
+	if (chd->owns_file && chd->file != NULL)
+		core_fclose(chd->file);
+
+#ifdef NEED_CACHE_HUNK
+	if (PRINTF_MAX_HUNK) printf("Max hunk = %d/%d\n", chd->maxhunk, chd->header.totalhunks);
+#endif
+	if (chd->file_cache)
+		free(chd->file_cache);
+
+	/* free our memory */
+	free(chd);
+}
+
+/*-------------------------------------------------
+    chd_core_file - return the associated
+    core_file
+-------------------------------------------------*/
+
+CHD_EXPORT core_file *chd_core_file(chd_file *chd)
+{
+	return chd->file;
+}
+
+/*-------------------------------------------------
+    chd_error_string - return an error string for
+    the given CHD error
+-------------------------------------------------*/
+
+CHD_EXPORT const char *chd_error_string(chd_error err)
+{
+	switch (err)
+	{
+		case CHDERR_NONE:						return "no error";
+		case CHDERR_NO_INTERFACE:				return "no drive interface";
+		case CHDERR_OUT_OF_MEMORY:				return "out of memory";
+		case CHDERR_INVALID_FILE:				return "invalid file";
+		case CHDERR_INVALID_PARAMETER:			return "invalid parameter";
+		case CHDERR_INVALID_DATA:				return "invalid data";
+		case CHDERR_FILE_NOT_FOUND:				return "file not found";
+		case CHDERR_REQUIRES_PARENT:			return "requires parent";
+		case CHDERR_FILE_NOT_WRITEABLE:			return "file not writeable";
+		case CHDERR_READ_ERROR:					return "read error";
+		case CHDERR_WRITE_ERROR:				return "write error";
+		case CHDERR_CODEC_ERROR:				return "codec error";
+		case CHDERR_INVALID_PARENT:				return "invalid parent";
+		case CHDERR_HUNK_OUT_OF_RANGE:			return "hunk out of range";
+		case CHDERR_DECOMPRESSION_ERROR:		return "decompression error";
+		case CHDERR_COMPRESSION_ERROR:			return "compression error";
+		case CHDERR_CANT_CREATE_FILE:			return "can't create file";
+		case CHDERR_CANT_VERIFY:				return "can't verify file";
+		case CHDERR_NOT_SUPPORTED:				return "operation not supported";
+		case CHDERR_METADATA_NOT_FOUND:			return "can't find metadata";
+		case CHDERR_INVALID_METADATA_SIZE:		return "invalid metadata size";
+		case CHDERR_UNSUPPORTED_VERSION:		return "unsupported CHD version";
+		case CHDERR_VERIFY_INCOMPLETE:			return "incomplete verify";
+		case CHDERR_INVALID_METADATA:			return "invalid metadata";
+		case CHDERR_INVALID_STATE:				return "invalid state";
+		case CHDERR_OPERATION_PENDING:			return "operation pending";
+		case CHDERR_NO_ASYNC_OPERATION:			return "no async operation in progress";
+		case CHDERR_UNSUPPORTED_FORMAT:			return "unsupported format";
+		default:								return "undocumented error";
+	}
+}
+
+/***************************************************************************
+    CHD HEADER MANAGEMENT
+***************************************************************************/
+
+/*-------------------------------------------------
+    chd_get_header - return a pointer to the
+    extracted header data
+-------------------------------------------------*/
+
+CHD_EXPORT const chd_header *chd_get_header(chd_file *chd)
+{
+	/* punt if NULL or invalid */
+	if (chd == NULL || chd->cookie != COOKIE_VALUE)
+		return NULL;
+
+	return &chd->header;
+}
+
+/***************************************************************************
+    CORE DATA READ/WRITE
+***************************************************************************/
+
+/*-------------------------------------------------
+    chd_read - read a single hunk from the CHD
+    file
+-------------------------------------------------*/
+
+CHD_EXPORT chd_error chd_read(chd_file *chd, UINT32 hunknum, void *buffer)
+{
+	/* punt if NULL or invalid */
+	if (chd == NULL || chd->cookie != COOKIE_VALUE)
+		return CHDERR_INVALID_PARAMETER;
+
+	/* if we're past the end, fail */
+	if (hunknum >= chd->header.totalhunks)
+		return CHDERR_HUNK_OUT_OF_RANGE;
+
+	/* perform the read */
+	return hunk_read_into_memory(chd, hunknum, (UINT8 *)buffer);
+}
+
+/***************************************************************************
+    METADATA MANAGEMENT
+***************************************************************************/
+
+/*-------------------------------------------------
+    chd_get_metadata - get the indexed metadata
+    of the given type
+-------------------------------------------------*/
+
+CHD_EXPORT chd_error chd_get_metadata(chd_file *chd, UINT32 searchtag, UINT32 searchindex, void *output, UINT32 outputlen, UINT32 *resultlen, UINT32 *resulttag, UINT8 *resultflags)
+{
+	metadata_entry metaentry;
+	chd_error err;
+	UINT32 count;
+
+	/* if we didn't find it, just return */
+	err = metadata_find_entry(chd, searchtag, searchindex, &metaentry);
+	if (err != CHDERR_NONE)
+	{
+		/* unless we're an old version and they are requesting hard disk metadata */
+		if (chd->header.version < 3 && (searchtag == HARD_DISK_METADATA_TAG || searchtag == CHDMETATAG_WILDCARD) && searchindex == 0)
+		{
+			char faux_metadata[256];
+			UINT32 faux_length;
+
+			/* fill in the faux metadata */
+			sprintf(faux_metadata, HARD_DISK_METADATA_FORMAT, chd->header.obsolete_cylinders, chd->header.obsolete_heads, chd->header.obsolete_sectors, chd->header.hunkbytes / chd->header.obsolete_hunksize);
+			faux_length = (UINT32)strlen(faux_metadata) + 1;
+
+			/* copy the metadata itself */
+			memcpy(output, faux_metadata, MIN(outputlen, faux_length));
+
+			/* return the length of the data and the tag */
+			if (resultlen != NULL)
+				*resultlen = faux_length;
+			if (resulttag != NULL)
+				*resulttag = HARD_DISK_METADATA_TAG;
+			return CHDERR_NONE;
+		}
+		return err;
+	}
+
+	/* read the metadata */
+	outputlen = MIN(outputlen, metaentry.length);
+	core_fseek(chd->file, metaentry.offset + METADATA_HEADER_SIZE, SEEK_SET);
+	count = core_fread(chd->file, output, outputlen);
+	if (count != outputlen)
+		return CHDERR_READ_ERROR;
+
+	/* return the length of the data and the tag */
+	if (resultlen != NULL)
+		*resultlen = metaentry.length;
+	if (resulttag != NULL)
+		*resulttag = metaentry.metatag;
+	if (resultflags != NULL)
+		*resultflags = metaentry.flags;
+	return CHDERR_NONE;
+}
+
+/***************************************************************************
+    CODEC INTERFACES
+***************************************************************************/
+
+/*-------------------------------------------------
+    chd_codec_config - set internal codec
+    parameters
+-------------------------------------------------*/
+
+CHD_EXPORT chd_error chd_codec_config(chd_file *chd, int param, void *config)
+{
+	return CHDERR_INVALID_PARAMETER;
+}
+
+/*-------------------------------------------------
+    chd_get_codec_name - get the name of a
+    particular codec
+-------------------------------------------------*/
+
+CHD_EXPORT const char *chd_get_codec_name(UINT32 codec)
+{
+	return "Unknown";
+}
+
+/***************************************************************************
+    INTERNAL HEADER OPERATIONS
+***************************************************************************/
+
+/*-------------------------------------------------
+    header_validate - check the validity of a
+    CHD header
+-------------------------------------------------*/
+
+static chd_error header_validate(const chd_header *header)
+{
+	int intfnum;
+
+	/* require a valid version */
+	if (header->version == 0 || header->version > CHD_HEADER_VERSION)
+		return CHDERR_UNSUPPORTED_VERSION;
+
+	/* require a valid length */
+	if ((header->version == 1 && header->length != CHD_V1_HEADER_SIZE) ||
+		(header->version == 2 && header->length != CHD_V2_HEADER_SIZE) ||
+		(header->version == 3 && header->length != CHD_V3_HEADER_SIZE) ||
+		(header->version == 4 && header->length != CHD_V4_HEADER_SIZE) ||
+		(header->version == 5 && header->length != CHD_V5_HEADER_SIZE))
+		return CHDERR_INVALID_PARAMETER;
+
+	/* Do not validate v5 header */
+	if (header->version <= 4)
+	{
+		/* require valid flags */
+		if (header->flags & CHDFLAGS_UNDEFINED)
+			return CHDERR_INVALID_PARAMETER;
+
+		/* require a supported compression mechanism */
+		for (intfnum = 0; intfnum < ARRAY_LENGTH(codec_interfaces); intfnum++)
+			if (codec_interfaces[intfnum].compression == header->compression[0])
+				break;
+
+		if (intfnum == ARRAY_LENGTH(codec_interfaces))
+			return CHDERR_INVALID_PARAMETER;
+
+		/* require a valid hunksize */
+		if (header->hunkbytes == 0 || header->hunkbytes >= 65536 * 256)
+			return CHDERR_INVALID_PARAMETER;
+
+		/* require a valid hunk count */
+		if (header->totalhunks == 0)
+			return CHDERR_INVALID_PARAMETER;
+
+		/* require a valid MD5 and/or SHA1 if we're using a parent */
+		if ((header->flags & CHDFLAGS_HAS_PARENT) && memcmp(header->parentmd5, nullmd5, sizeof(nullmd5)) == 0 && memcmp(header->parentsha1, nullsha1, sizeof(nullsha1)) == 0)
+			return CHDERR_INVALID_PARAMETER;
+
+		/* if we're V3 or later, the obsolete fields must be 0 */
+		if (header->version >= 3 &&
+			(header->obsolete_cylinders != 0 || header->obsolete_sectors != 0 ||
+			 header->obsolete_heads != 0 || header->obsolete_hunksize != 0))
+			return CHDERR_INVALID_PARAMETER;
+
+		/* if we're pre-V3, the obsolete fields must NOT be 0 */
+		if (header->version < 3 &&
+			(header->obsolete_cylinders == 0 || header->obsolete_sectors == 0 ||
+			 header->obsolete_heads == 0 || header->obsolete_hunksize == 0))
+			return CHDERR_INVALID_PARAMETER;
+	}
+
+	return CHDERR_NONE;
+}
+
+/*-------------------------------------------------
+    header_guess_unitbytes - for older CHD formats,
+    guess at the bytes/unit based on metadata
+-------------------------------------------------*/
+
+static UINT32 header_guess_unitbytes(chd_file *chd)
+{
+	/* look for hard disk metadata; if found, then the unit size == sector size */
+	char metadata[512];
+	int i0, i1, i2, i3;
+	if (chd_get_metadata(chd, HARD_DISK_METADATA_TAG, 0, metadata, sizeof(metadata), NULL, NULL, NULL) == CHDERR_NONE &&
+		sscanf(metadata, HARD_DISK_METADATA_FORMAT, &i0, &i1, &i2, &i3) == 4)
+		return i3;
+
+	/* look for CD-ROM metadata; if found, then the unit size == CD frame size */
+	if (chd_get_metadata(chd, CDROM_OLD_METADATA_TAG, 0, metadata, sizeof(metadata), NULL, NULL, NULL) == CHDERR_NONE ||
+		chd_get_metadata(chd, CDROM_TRACK_METADATA_TAG, 0, metadata, sizeof(metadata), NULL, NULL, NULL) == CHDERR_NONE ||
+		chd_get_metadata(chd, CDROM_TRACK_METADATA2_TAG, 0, metadata, sizeof(metadata), NULL, NULL, NULL) == CHDERR_NONE ||
+		chd_get_metadata(chd, GDROM_OLD_METADATA_TAG, 0, metadata, sizeof(metadata), NULL, NULL, NULL) == CHDERR_NONE ||
+		chd_get_metadata(chd, GDROM_TRACK_METADATA_TAG, 0, metadata, sizeof(metadata), NULL, NULL, NULL) == CHDERR_NONE)
+		return CD_FRAME_SIZE;
+
+	/* otherwise, just map 1:1 with the hunk size */
+	return chd->header.hunkbytes;
+}
+
+/*-------------------------------------------------
+    header_read - read a CHD header into the
+    internal data structure
+-------------------------------------------------*/
+
+static chd_error header_read(chd_file *chd, chd_header *header)
+{
+	UINT8 rawheader[CHD_MAX_HEADER_SIZE];
+	UINT32 count;
+
+	/* punt if NULL */
+	if (header == NULL)
+		return CHDERR_INVALID_PARAMETER;
+
+	/* punt if invalid file */
+	if (chd->file == NULL)
+		return CHDERR_INVALID_FILE;
+
+	/* seek and read */
+	core_fseek(chd->file, 0, SEEK_SET);
+	count = core_fread(chd->file, rawheader, sizeof(rawheader));
+	if (count != sizeof(rawheader))
+		return CHDERR_READ_ERROR;
+
+	/* verify the tag */
+	if (strncmp((char *)rawheader, "MComprHD", 8) != 0)
+		return CHDERR_INVALID_DATA;
+
+	/* extract the direct data */
+	memset(header, 0, sizeof(*header));
+	header->length        = get_bigendian_uint32(&rawheader[8]);
+	header->version       = get_bigendian_uint32(&rawheader[12]);
+
+	/* make sure it's a version we understand */
+	if (header->version == 0 || header->version > CHD_HEADER_VERSION)
+		return CHDERR_UNSUPPORTED_VERSION;
+
+	/* make sure the length is expected */
+	if ((header->version == 1 && header->length != CHD_V1_HEADER_SIZE) ||
+		(header->version == 2 && header->length != CHD_V2_HEADER_SIZE) ||
+		(header->version == 3 && header->length != CHD_V3_HEADER_SIZE) ||
+		(header->version == 4 && header->length != CHD_V4_HEADER_SIZE) ||
+		(header->version == 5 && header->length != CHD_V5_HEADER_SIZE))
+
+		return CHDERR_INVALID_DATA;
+
+	/* extract the common data */
+	header->flags         	= get_bigendian_uint32(&rawheader[16]);
+	header->compression[0]	= get_bigendian_uint32(&rawheader[20]);
+	header->compression[1]	= CHD_CODEC_NONE;
+	header->compression[2]	= CHD_CODEC_NONE;
+	header->compression[3]	= CHD_CODEC_NONE;
+
+	/* extract the V1/V2-specific data */
+	if (header->version < 3)
+	{
+		int seclen = (header->version == 1) ? CHD_V1_SECTOR_SIZE : get_bigendian_uint32(&rawheader[76]);
+		header->obsolete_hunksize  = get_bigendian_uint32(&rawheader[24]);
+		header->totalhunks         = get_bigendian_uint32(&rawheader[28]);
+		header->obsolete_cylinders = get_bigendian_uint32(&rawheader[32]);
+		header->obsolete_heads     = get_bigendian_uint32(&rawheader[36]);
+		header->obsolete_sectors   = get_bigendian_uint32(&rawheader[40]);
+		memcpy(header->md5, &rawheader[44], CHD_MD5_BYTES);
+		memcpy(header->parentmd5, &rawheader[60], CHD_MD5_BYTES);
+		header->logicalbytes = (UINT64)header->obsolete_cylinders * (UINT64)header->obsolete_heads * (UINT64)header->obsolete_sectors * (UINT64)seclen;
+		header->hunkbytes = seclen * header->obsolete_hunksize;
+		header->unitbytes          = header_guess_unitbytes(chd);
+		header->unitcount          = (header->logicalbytes + header->unitbytes - 1) / header->unitbytes;
+		header->metaoffset = 0;
+	}
+
+	/* extract the V3-specific data */
+	else if (header->version == 3)
+	{
+		header->totalhunks   = get_bigendian_uint32(&rawheader[24]);
+		header->logicalbytes = get_bigendian_uint64(&rawheader[28]);
+		header->metaoffset   = get_bigendian_uint64(&rawheader[36]);
+		memcpy(header->md5, &rawheader[44], CHD_MD5_BYTES);
+		memcpy(header->parentmd5, &rawheader[60], CHD_MD5_BYTES);
+		header->hunkbytes    = get_bigendian_uint32(&rawheader[76]);
+		header->unitbytes    = header_guess_unitbytes(chd);
+		header->unitcount    = (header->logicalbytes + header->unitbytes - 1) / header->unitbytes;
+		memcpy(header->sha1, &rawheader[80], CHD_SHA1_BYTES);
+		memcpy(header->parentsha1, &rawheader[100], CHD_SHA1_BYTES);
+	}
+
+	/* extract the V4-specific data */
+	else if (header->version == 4)
+	{
+		header->totalhunks   = get_bigendian_uint32(&rawheader[24]);
+		header->logicalbytes = get_bigendian_uint64(&rawheader[28]);
+		header->metaoffset   = get_bigendian_uint64(&rawheader[36]);
+		header->hunkbytes    = get_bigendian_uint32(&rawheader[44]);
+		header->unitbytes    = header_guess_unitbytes(chd);
+		header->unitcount    = (header->logicalbytes + header->unitbytes - 1) / header->unitbytes;
+		memcpy(header->sha1, &rawheader[48], CHD_SHA1_BYTES);
+		memcpy(header->parentsha1, &rawheader[68], CHD_SHA1_BYTES);
+		memcpy(header->rawsha1, &rawheader[88], CHD_SHA1_BYTES);
+	}
+
+	/* extract the V5-specific data */
+	else if (header->version == 5)
+	{
+		/* TODO */
+		header->compression[0]  = get_bigendian_uint32(&rawheader[16]);
+		header->compression[1]  = get_bigendian_uint32(&rawheader[20]);
+		header->compression[2]  = get_bigendian_uint32(&rawheader[24]);
+		header->compression[3]  = get_bigendian_uint32(&rawheader[28]);
+		header->logicalbytes    = get_bigendian_uint64(&rawheader[32]);
+		header->mapoffset       = get_bigendian_uint64(&rawheader[40]);
+		header->metaoffset      = get_bigendian_uint64(&rawheader[48]);
+		header->hunkbytes       = get_bigendian_uint32(&rawheader[56]);
+		header->hunkcount       = (header->logicalbytes + header->hunkbytes - 1) / header->hunkbytes;
+		header->unitbytes       = get_bigendian_uint32(&rawheader[60]);
+		header->unitcount       = (header->logicalbytes + header->unitbytes - 1) / header->unitbytes;
+		memcpy(header->sha1, &rawheader[84], CHD_SHA1_BYTES);
+		memcpy(header->parentsha1, &rawheader[104], CHD_SHA1_BYTES);
+		memcpy(header->rawsha1, &rawheader[64], CHD_SHA1_BYTES);
+
+		/* determine properties of map entries */
+		header->mapentrybytes = chd_compressed(header) ? 12 : 4;
+
+		/* hack */
+		header->totalhunks 		= header->hunkcount;
+	}
+
+	/* Unknown version */
+	else
+	{
+		/* TODO */
+	}
+
+	/* guess it worked */
+	return CHDERR_NONE;
+}
+
+/***************************************************************************
+    INTERNAL HUNK READ/WRITE
+***************************************************************************/
+
+/*-------------------------------------------------
+    hunk_read_compressed - read a compressed
+    hunk
+-------------------------------------------------*/
+
+static UINT8* hunk_read_compressed(chd_file *chd, UINT64 offset, size_t size)
+{
+#ifdef _MSC_VER
+	size_t bytes;
+#else
+	ssize_t bytes;
+#endif
+	if (chd->file_cache != NULL)
+	{
+		return chd->file_cache + offset;
+	}
+	else
+	{
+		core_fseek(chd->file, offset, SEEK_SET);
+		bytes = core_fread(chd->file, chd->compressed, size);
+		if (bytes != size)
+			return NULL;
+		return chd->compressed;
+	}
+}
+
+/*-------------------------------------------------
+    hunk_read_uncompressed - read an uncompressed
+    hunk
+-------------------------------------------------*/
+
+static chd_error hunk_read_uncompressed(chd_file *chd, UINT64 offset, size_t size, UINT8 *dest)
+{
+#ifdef _MSC_VER
+	size_t bytes;
+#else
+	ssize_t bytes;
+#endif
+	if (chd->file_cache != NULL)
+	{
+		memcpy(dest, chd->file_cache + offset, size);
+	}
+	else
+	{
+		core_fseek(chd->file, offset, SEEK_SET);
+		bytes = core_fread(chd->file, dest, size);
+		if (bytes != size)
+			return CHDERR_READ_ERROR;
+	}
+	return CHDERR_NONE;
+}
+
+#ifdef NEED_CACHE_HUNK
+/*-------------------------------------------------
+    hunk_read_into_cache - read a hunk into
+    the CHD's hunk cache
+-------------------------------------------------*/
+
+static chd_error hunk_read_into_cache(chd_file *chd, UINT32 hunknum)
+{
+	chd_error err;
+
+	/* track the max */
+	if (hunknum > chd->maxhunk)
+		chd->maxhunk = hunknum;
+
+	/* if we're already in the cache, we're done */
+	if (chd->cachehunk == hunknum)
+		return CHDERR_NONE;
+	chd->cachehunk = ~0;
+
+	/* otherwise, read the data */
+	err = hunk_read_into_memory(chd, hunknum, chd->cache);
+	if (err != CHDERR_NONE)
+		return err;
+
+	/* mark the hunk successfully cached in */
+	chd->cachehunk = hunknum;
+	return CHDERR_NONE;
+}
+#endif
+
+/*-------------------------------------------------
+    hunk_read_into_memory - read a hunk into
+    memory at the given location
+-------------------------------------------------*/
+
+static chd_error hunk_read_into_memory(chd_file *chd, UINT32 hunknum, UINT8 *dest)
+{
+	chd_error err;
+
+	/* punt if no file */
+	if (chd->file == NULL)
+		return CHDERR_INVALID_FILE;
+
+	/* return an error if out of range */
+	if (hunknum >= chd->header.totalhunks)
+		return CHDERR_HUNK_OUT_OF_RANGE;
+
+	if (dest == NULL)
+		return CHDERR_INVALID_PARAMETER;
+
+	if (chd->header.version < 5)
+	{
+		map_entry *entry = &chd->map[hunknum];
+		UINT32 bytes;
+		UINT8* compressed_bytes;
+
+		/* switch off the entry type */
+		switch (entry->flags & MAP_ENTRY_FLAG_TYPE_MASK)
+		{
+			/* compressed data */
+			case V34_MAP_ENTRY_TYPE_COMPRESSED:
+            {
+               void *codec = NULL;
+
+				/* read it into the decompression buffer */
+				compressed_bytes = hunk_read_compressed(chd, entry->offset, entry->length);
+				if (compressed_bytes == NULL)
+					return CHDERR_READ_ERROR;
+
+				/* now decompress using the codec */
+				err = CHDERR_NONE;
+				codec = &chd->zlib_codec_data;
+				if (chd->codecintf[0]->decompress != NULL)
+					err = (*chd->codecintf[0]->decompress)(codec, compressed_bytes, entry->length, dest, chd->header.hunkbytes);
+				if (err != CHDERR_NONE)
+					return err;
+				break;
+			}
+
+			/* uncompressed data */
+			case V34_MAP_ENTRY_TYPE_UNCOMPRESSED:
+				err = hunk_read_uncompressed(chd, entry->offset, chd->header.hunkbytes, dest);
+				if (err != CHDERR_NONE)
+					return err;
+				break;
+
+			/* mini-compressed data */
+			case V34_MAP_ENTRY_TYPE_MINI:
+				put_bigendian_uint64(&dest[0], entry->offset);
+				for (bytes = 8; bytes < chd->header.hunkbytes; bytes++)
+					dest[bytes] = dest[bytes - 8];
+				break;
+
+			/* self-referenced data */
+			case V34_MAP_ENTRY_TYPE_SELF_HUNK:
+#ifdef NEED_CACHE_HUNK
+				if (chd->cachehunk == entry->offset && dest == chd->cache)
+					break;
+#endif
+				return hunk_read_into_memory(chd, entry->offset, dest);
+
+			/* parent-referenced data */
+			case V34_MAP_ENTRY_TYPE_PARENT_HUNK:
+				err = hunk_read_into_memory(chd->parent, entry->offset, dest);
+				if (err != CHDERR_NONE)
+					return err;
+				break;
+		}
+		return CHDERR_NONE;
+	}
+	else
+	{
+		void* codec = NULL;
+		/* get a pointer to the map entry */
+		uint64_t blockoffs;
+		uint32_t blocklen;
+#ifdef VERIFY_BLOCK_CRC
+		uint16_t blockcrc;
+#endif
+		uint8_t *rawmap = &chd->header.rawmap[chd->header.mapentrybytes * hunknum];
+		UINT8* compressed_bytes;
+
+		/* uncompressed case */
+		if (!chd_compressed(&chd->header))
+		{
+			blockoffs = (uint64_t)get_bigendian_uint32(rawmap) * (uint64_t)chd->header.hunkbytes;
+			if (blockoffs != 0) {
+				core_fseek(chd->file, blockoffs, SEEK_SET);
+				int result = core_fread(chd->file, dest, chd->header.hunkbytes);
+			/* TODO
+			else if (m_parent_missing)
+				throw CHDERR_REQUIRES_PARENT; */
+			} else if (chd->parent) {
+				err = hunk_read_into_memory(chd->parent, hunknum, dest);
+				if (err != CHDERR_NONE)
+					return err;
+			} else {
+				memset(dest, 0, chd->header.hunkbytes);
+			}
+
+			return CHDERR_NONE;
+		}
+
+		/* compressed case */
+		blocklen = get_bigendian_uint24(&rawmap[1]);
+		blockoffs = get_bigendian_uint48(&rawmap[4]);
+#ifdef VERIFY_BLOCK_CRC
+		blockcrc = get_bigendian_uint16(&rawmap[10]);
+#endif
+		codec = NULL;
+		switch (rawmap[0])
+		{
+			case COMPRESSION_TYPE_0:
+			case COMPRESSION_TYPE_1:
+			case COMPRESSION_TYPE_2:
+			case COMPRESSION_TYPE_3:
+				compressed_bytes = hunk_read_compressed(chd, blockoffs, blocklen);
+				if (compressed_bytes == NULL)
+					return CHDERR_READ_ERROR;
+				switch (chd->codecintf[rawmap[0]]->compression)
+				{
+					case CHD_CODEC_CD_LZMA:
+						codec = &chd->cdlz_codec_data;
+						break;
+
+					case CHD_CODEC_ZLIB:
+						codec = &chd->zlib_codec_data;
+						break;
+
+					case CHD_CODEC_CD_ZLIB:
+						codec = &chd->cdzl_codec_data;
+						break;
+
+					case CHD_CODEC_CD_FLAC:
+						codec = &chd->cdfl_codec_data;
+						break;
+				}
+				if (codec==NULL)
+					return CHDERR_CODEC_ERROR;
+				err = chd->codecintf[rawmap[0]]->decompress(codec, compressed_bytes, blocklen, dest, chd->header.hunkbytes);
+				if (err != CHDERR_NONE)
+					return err;
+#ifdef VERIFY_BLOCK_CRC
+				if (crc16(dest, chd->header.hunkbytes) != blockcrc)
+					return CHDERR_DECOMPRESSION_ERROR;
+#endif
+				return CHDERR_NONE;
+
+			case COMPRESSION_NONE:
+				err = hunk_read_uncompressed(chd, blockoffs, blocklen, dest);
+				if (err != CHDERR_NONE)
+					return err;
+#ifdef VERIFY_BLOCK_CRC
+				if (crc16(dest, chd->header.hunkbytes) != blockcrc)
+					return CHDERR_DECOMPRESSION_ERROR;
+#endif
+				return CHDERR_NONE;
+
+			case COMPRESSION_SELF:
+				return hunk_read_into_memory(chd, blockoffs, dest);
+
+			case COMPRESSION_PARENT:
+#if 0
+				/* TODO */
+				if (m_parent_missing)
+					return CHDERR_REQUIRES_PARENT;
+				return m_parent->read_bytes(uint64_t(blockoffs) * uint64_t(m_parent->unit_bytes()), dest, m_hunkbytes);
+#endif
+				return CHDERR_DECOMPRESSION_ERROR;
+		}
+		return CHDERR_NONE;
+	}
+
+	/* We should not reach this code */
+	return CHDERR_DECOMPRESSION_ERROR;
+}
+
+/***************************************************************************
+    INTERNAL MAP ACCESS
+***************************************************************************/
+
+/*-------------------------------------------------
+    map_read - read the initial sector map
+-------------------------------------------------*/
+
+static chd_error map_read(chd_file *chd)
+{
+	UINT32 entrysize = (chd->header.version < 3) ? OLD_MAP_ENTRY_SIZE : MAP_ENTRY_SIZE;
+	UINT8 raw_map_entries[MAP_STACK_ENTRIES * MAP_ENTRY_SIZE];
+	UINT64 fileoffset, maxoffset = 0;
+	UINT8 cookie[MAP_ENTRY_SIZE];
+	UINT32 count;
+	chd_error err;
+	int i;
+
+	/* first allocate memory */
+	chd->map = (map_entry *)malloc(sizeof(chd->map[0]) * chd->header.totalhunks);
+	if (!chd->map)
+		return CHDERR_OUT_OF_MEMORY;
+
+	/* read the map entries in in chunks and extract to the map list */
+	fileoffset = chd->header.length;
+	for (i = 0; i < chd->header.totalhunks; i += MAP_STACK_ENTRIES)
+	{
+		/* compute how many entries this time */
+		int entries = chd->header.totalhunks - i, j;
+		if (entries > MAP_STACK_ENTRIES)
+			entries = MAP_STACK_ENTRIES;
+
+		/* read that many */
+		core_fseek(chd->file, fileoffset, SEEK_SET);
+		count = core_fread(chd->file, raw_map_entries, entries * entrysize);
+		if (count != entries * entrysize)
+		{
+			err = CHDERR_READ_ERROR;
+			goto cleanup;
+		}
+		fileoffset += entries * entrysize;
+
+		/* process that many */
+		if (entrysize == MAP_ENTRY_SIZE)
+		{
+			for (j = 0; j < entries; j++)
+				map_extract(&raw_map_entries[j * MAP_ENTRY_SIZE], &chd->map[i + j]);
+		}
+		else
+		{
+			for (j = 0; j < entries; j++)
+				map_extract_old(&raw_map_entries[j * OLD_MAP_ENTRY_SIZE], &chd->map[i + j], chd->header.hunkbytes);
+		}
+
+		/* track the maximum offset */
+		for (j = 0; j < entries; j++)
+			if ((chd->map[i + j].flags & MAP_ENTRY_FLAG_TYPE_MASK) == V34_MAP_ENTRY_TYPE_COMPRESSED ||
+				(chd->map[i + j].flags & MAP_ENTRY_FLAG_TYPE_MASK) == V34_MAP_ENTRY_TYPE_UNCOMPRESSED)
+				maxoffset = MAX(maxoffset, chd->map[i + j].offset + chd->map[i + j].length);
+	}
+
+	/* verify the cookie */
+	core_fseek(chd->file, fileoffset, SEEK_SET);
+	count = core_fread(chd->file, &cookie, entrysize);
+	if (count != entrysize || memcmp(&cookie, END_OF_LIST_COOKIE, entrysize))
+	{
+		err = CHDERR_INVALID_FILE;
+		goto cleanup;
+	}
+
+	/* verify the length */
+	if (maxoffset > core_fsize(chd->file))
+	{
+		err = CHDERR_INVALID_FILE;
+		goto cleanup;
+	}
+	return CHDERR_NONE;
+
+cleanup:
+	if (chd->map)
+		free(chd->map);
+	chd->map = NULL;
+	return err;
+}
+
+/***************************************************************************
+    INTERNAL METADATA ACCESS
+***************************************************************************/
+
+/*-------------------------------------------------
+    metadata_find_entry - find a metadata entry
+-------------------------------------------------*/
+
+static chd_error metadata_find_entry(chd_file *chd, UINT32 metatag, UINT32 metaindex, metadata_entry *metaentry)
+{
+	/* start at the beginning */
+	metaentry->offset = chd->header.metaoffset;
+	metaentry->prev = 0;
+
+	/* loop until we run out of options */
+	while (metaentry->offset != 0)
+	{
+		UINT8	raw_meta_header[METADATA_HEADER_SIZE];
+		UINT32	count;
+
+		/* read the raw header */
+		core_fseek(chd->file, metaentry->offset, SEEK_SET);
+		count = core_fread(chd->file, raw_meta_header, sizeof(raw_meta_header));
+		if (count != sizeof(raw_meta_header))
+			break;
+
+		/* extract the data */
+		metaentry->metatag = get_bigendian_uint32(&raw_meta_header[0]);
+		metaentry->length = get_bigendian_uint32(&raw_meta_header[4]);
+		metaentry->next = get_bigendian_uint64(&raw_meta_header[8]);
+
+		/* flags are encoded in the high byte of length */
+		metaentry->flags = metaentry->length >> 24;
+		metaentry->length &= 0x00ffffff;
+
+		/* if we got a match, proceed */
+		if (metatag == CHDMETATAG_WILDCARD || metaentry->metatag == metatag)
+			if (metaindex-- == 0)
+				return CHDERR_NONE;
+
+		/* no match, fetch the next link */
+		metaentry->prev = metaentry->offset;
+		metaentry->offset = metaentry->next;
+	}
+
+	/* if we get here, we didn't find it */
+	return CHDERR_METADATA_NOT_FOUND;
+}
+
+/***************************************************************************
+    ZLIB COMPRESSION CODEC
+***************************************************************************/
+
+/*-------------------------------------------------
+    zlib_codec_init - initialize the ZLIB codec
+-------------------------------------------------*/
+
+static chd_error zlib_codec_init(void *codec, uint32_t hunkbytes)
+{
+	int zerr;
+	chd_error err;
+	zlib_codec_data *data = (zlib_codec_data*)codec;
+
+	/* clear the buffers */
+	memset(data, 0, sizeof(zlib_codec_data));
+
+	/* init the inflater first */
+	data->inflater.next_in = (Bytef *)data;	/* bogus, but that's ok */
+	data->inflater.avail_in = 0;
+	data->inflater.zalloc = zlib_fast_alloc;
+	data->inflater.zfree = zlib_fast_free;
+	data->inflater.opaque = &data->allocator;
+	zerr = inflateInit2(&data->inflater, -MAX_WBITS);
+
+	/* convert errors */
+	if (zerr == Z_MEM_ERROR)
+		err = CHDERR_OUT_OF_MEMORY;
+	else if (zerr != Z_OK)
+		err = CHDERR_CODEC_ERROR;
+	else
+		err = CHDERR_NONE;
+
+	/* handle an error */
+	if (err != CHDERR_NONE)
+		free(data);
+
+	return err;
+}
+
+/*-------------------------------------------------
+    zlib_codec_free - free data for the ZLIB
+    codec
+-------------------------------------------------*/
+
+static void zlib_codec_free(void *codec)
+{
+	zlib_codec_data *data = (zlib_codec_data *)codec;
+
+	/* deinit the streams */
+	if (data != NULL)
+	{
+		int i;
+
+		inflateEnd(&data->inflater);
+
+		/* free our fast memory */
+		zlib_allocator_free(&data->allocator);
+	}
+}
+
+/*-------------------------------------------------
+    zlib_codec_decompress - decompress data using
+    the ZLIB codec
+-------------------------------------------------*/
+
+static chd_error zlib_codec_decompress(void *codec, const uint8_t *src, uint32_t complen, uint8_t *dest, uint32_t destlen)
+{
+	zlib_codec_data *data = (zlib_codec_data *)codec;
+	int zerr;
+
+	/* reset the decompressor */
+	data->inflater.next_in = (Bytef *)src;
+	data->inflater.avail_in = complen;
+	data->inflater.total_in = 0;
+	data->inflater.next_out = (Bytef *)dest;
+	data->inflater.avail_out = destlen;
+	data->inflater.total_out = 0;
+	zerr = inflateReset(&data->inflater);
+	if (zerr != Z_OK)
+		return CHDERR_DECOMPRESSION_ERROR;
+
+	/* do it */
+	zerr = inflate(&data->inflater, Z_FINISH);
+	if (data->inflater.total_out != destlen)
+		return CHDERR_DECOMPRESSION_ERROR;
+
+	return CHDERR_NONE;
+}
+
+/*-------------------------------------------------
+    zlib_fast_alloc - fast malloc for ZLIB, which
+    allocates and frees memory frequently
+-------------------------------------------------*/
+
+/* Huge alignment values for possible SIMD optimization by compiler (NEON, SSE, AVX) */
+#define ZLIB_MIN_ALIGNMENT_BITS 512
+#define ZLIB_MIN_ALIGNMENT_BYTES (ZLIB_MIN_ALIGNMENT_BITS / 8)
+
+static voidpf zlib_fast_alloc(voidpf opaque, uInt items, uInt size)
+{
+	zlib_allocator *alloc = (zlib_allocator *)opaque;
+	uintptr_t paddr = 0;
+	UINT32 *ptr;
+	int i;
+
+	/* compute the size, rounding to the nearest 1k */
+	size = (size * items + 0x3ff) & ~0x3ff;
+
+	/* reuse a hunk if we can */
+	for (i = 0; i < MAX_ZLIB_ALLOCS; i++)
+	{
+		ptr = alloc->allocptr[i];
+		if (ptr && size == *ptr)
+		{
+			/* set the low bit of the size so we don't match next time */
+			*ptr |= 1;
+
+			/* return aligned block address */
+			return (voidpf)(alloc->allocptr2[i]);
+		}
+	}
+
+	/* alloc a new one */
+    ptr = (UINT32 *)malloc(size + sizeof(UINT32) + ZLIB_MIN_ALIGNMENT_BYTES);
+	if (!ptr)
+		return NULL;
+
+	/* put it into the list */
+	for (i = 0; i < MAX_ZLIB_ALLOCS; i++)
+		if (!alloc->allocptr[i])
+		{
+			alloc->allocptr[i] = ptr;
+			paddr = (((uintptr_t)ptr) + sizeof(UINT32) + (ZLIB_MIN_ALIGNMENT_BYTES-1)) & (~(ZLIB_MIN_ALIGNMENT_BYTES-1));
+			alloc->allocptr2[i] = (uint32_t*)paddr;
+			break;
+		}
+
+	/* set the low bit of the size so we don't match next time */
+	*ptr = size | 1;
+
+	/* return aligned block address */
+	return (voidpf)paddr;
+}
+
+/*-------------------------------------------------
+    zlib_fast_free - fast free for ZLIB, which
+    allocates and frees memory frequently
+-------------------------------------------------*/
+
+static void zlib_fast_free(voidpf opaque, voidpf address)
+{
+	zlib_allocator *alloc = (zlib_allocator *)opaque;
+	UINT32 *ptr = (UINT32 *)address;
+	int i;
+
+	/* find the hunk */
+	for (i = 0; i < MAX_ZLIB_ALLOCS; i++)
+		if (ptr == alloc->allocptr2[i])
+		{
+			/* clear the low bit of the size to allow matches */
+			*(alloc->allocptr[i]) &= ~1;
+			return;
+		}
+}
+
+/*-------------------------------------------------
+    zlib_allocator_free
+-------------------------------------------------*/
+static void zlib_allocator_free(voidpf opaque)
+{
+	zlib_allocator *alloc = (zlib_allocator *)opaque;
+	int i;
+
+	for (i = 0; i < MAX_ZLIB_ALLOCS; i++)
+		if (alloc->allocptr[i])
+			free(alloc->allocptr[i]);
+}
diff --git a/deps/libchdr/src/libchdr_flac.c b/deps/libchdr/src/libchdr_flac.c
new file mode 100644
index 0000000..54d374f
--- /dev/null
+++ b/deps/libchdr/src/libchdr_flac.c
@@ -0,0 +1,302 @@
+/* license:BSD-3-Clause
+ * copyright-holders:Aaron Giles
+***************************************************************************
+
+    flac.c
+
+    FLAC compression wrappers
+
+***************************************************************************/
+
+#include <assert.h>
+#include <string.h>
+
+#include <libchdr/flac.h>
+#define DR_FLAC_IMPLEMENTATION
+#include <dr_libs/dr_flac.h>
+
+/***************************************************************************
+ *  FLAC DECODER
+ ***************************************************************************
+ */
+
+static size_t flac_decoder_read_callback(void *userdata, void *buffer, size_t bytes);
+static drflac_bool32 flac_decoder_seek_callback(void *userdata, int offset, drflac_seek_origin origin);
+static void flac_decoder_metadata_callback(void *userdata, drflac_metadata *metadata);
+static void flac_decoder_write_callback(void *userdata, void *buffer, size_t len);
+
+
+/* getters (valid after reset) */
+static uint32_t sample_rate(flac_decoder *decoder)  { return decoder->sample_rate; }
+static uint8_t channels(flac_decoder *decoder)  { return decoder->channels; }
+static uint8_t bits_per_sample(flac_decoder *decoder) { return decoder->bits_per_sample; }
+
+/*-------------------------------------------------
+ *  flac_decoder - constructor
+ *-------------------------------------------------
+ */
+
+int flac_decoder_init(flac_decoder *decoder)
+{
+	decoder->decoder = NULL;
+	decoder->sample_rate = 0;
+	decoder->channels = 0;
+	decoder->bits_per_sample = 0;
+	decoder->compressed_offset = 0;
+	decoder->compressed_start = NULL;
+	decoder->compressed_length = 0;
+	decoder->compressed2_start = NULL;
+	decoder->compressed2_length = 0;
+	decoder->uncompressed_offset = 0;
+	decoder->uncompressed_length = 0;
+	decoder->uncompressed_swap = 0;
+	return 0;
+}
+
+/*-------------------------------------------------
+ *  flac_decoder - destructor
+ *-------------------------------------------------
+ */
+
+void flac_decoder_free(flac_decoder* decoder)
+{
+	if ((decoder != NULL) && (decoder->decoder != NULL))
+		drflac_close(decoder->decoder);
+	decoder->decoder = NULL;
+}
+
+/*-------------------------------------------------
+ *  reset - reset state with the original
+ *  parameters
+ *-------------------------------------------------
+ */
+
+static int flac_decoder_internal_reset(flac_decoder* decoder)
+{
+	decoder->compressed_offset = 0;
+	flac_decoder_free(decoder);
+	decoder->decoder = drflac_open_with_metadata(
+		flac_decoder_read_callback, flac_decoder_seek_callback,
+		flac_decoder_metadata_callback, decoder, NULL);
+	return (decoder->decoder != NULL);
+}
+
+/*-------------------------------------------------
+ *  reset - reset state with new memory parameters
+ *  and a custom-generated header
+ *-------------------------------------------------
+ */
+
+int flac_decoder_reset(flac_decoder* decoder, uint32_t sample_rate, uint8_t num_channels, uint32_t block_size, const void *buffer, uint32_t length)
+{
+	/* modify the template header with our parameters */
+	static const uint8_t s_header_template[0x2a] =
+	{
+		0x66, 0x4C, 0x61, 0x43,                         /* +00: 'fLaC' stream header */
+		0x80,                                           /* +04: metadata block type 0 (STREAMINFO), */
+								/*      flagged as last block */
+		0x00, 0x00, 0x22,                               /* +05: metadata block length = 0x22 */
+		0x00, 0x00,                                     /* +08: minimum block size */
+		0x00, 0x00,                                     /* +0A: maximum block size */
+		0x00, 0x00, 0x00,                               /* +0C: minimum frame size (0 == unknown) */
+		0x00, 0x00, 0x00,                               /* +0F: maximum frame size (0 == unknown) */
+		0x0A, 0xC4, 0x42, 0xF0, 0x00, 0x00, 0x00, 0x00, /* +12: sample rate (0x0ac44 == 44100), */
+								/*      numchannels (2), sample bits (16), */
+								/*      samples in stream (0 == unknown) */
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* +1A: MD5 signature (0 == none) */
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00  /* +2A: start of stream data */
+	};
+	memcpy(decoder->custom_header, s_header_template, sizeof(s_header_template));
+	decoder->custom_header[0x08] = decoder->custom_header[0x0a] = (block_size*num_channels) >> 8;
+	decoder->custom_header[0x09] = decoder->custom_header[0x0b] = (block_size*num_channels) & 0xff;
+	decoder->custom_header[0x12] = sample_rate >> 12;
+	decoder->custom_header[0x13] = sample_rate >> 4;
+	decoder->custom_header[0x14] = (sample_rate << 4) | ((num_channels - 1) << 1);
+
+	/* configure the header ahead of the provided buffer */
+	decoder->compressed_start = (const uint8_t *)(decoder->custom_header);
+	decoder->compressed_length = sizeof(decoder->custom_header);
+	decoder->compressed2_start = (const uint8_t *)(buffer);
+	decoder->compressed2_length = length;
+	return flac_decoder_internal_reset(decoder);
+}
+
+/*-------------------------------------------------
+ *  decode_interleaved - decode to an interleaved
+ *  sound stream
+ *-------------------------------------------------
+ */
+
+int flac_decoder_decode_interleaved(flac_decoder* decoder, int16_t *samples, uint32_t num_samples, int swap_endian)
+{
+	/* configure the uncompressed buffer */
+	memset(decoder->uncompressed_start, 0, sizeof(decoder->uncompressed_start));
+	decoder->uncompressed_start[0] = samples;
+	decoder->uncompressed_offset = 0;
+	decoder->uncompressed_length = num_samples;
+	decoder->uncompressed_swap = swap_endian;
+
+#define	BUFFER	2352	/* bytes per CD audio sector */
+	int16_t buffer[BUFFER];
+	uint32_t buf_samples = BUFFER / channels(decoder);
+	/* loop until we get everything we want */
+	while (decoder->uncompressed_offset < decoder->uncompressed_length) {
+		uint32_t frames = (num_samples < buf_samples ? num_samples : buf_samples);
+		if (!drflac_read_pcm_frames_s16(decoder->decoder, frames, buffer))
+			return 0;
+		flac_decoder_write_callback(decoder, buffer, frames*sizeof(*buffer)*channels(decoder));
+		num_samples -= frames;
+	}
+	return 1;
+}
+
+/*-------------------------------------------------
+ *  finish - finish up the decode
+ *-------------------------------------------------
+ */
+
+uint32_t flac_decoder_finish(flac_decoder* decoder)
+{
+	/* get the final decoding position and move forward */
+	drflac *flac = decoder->decoder;
+	uint64_t position = decoder->compressed_offset;
+
+	/* ugh... there's no function to obtain bytes used in drflac :-/ */
+	position -= DRFLAC_CACHE_L2_LINES_REMAINING(&flac->bs) * sizeof(drflac_cache_t);
+	position -= DRFLAC_CACHE_L1_BITS_REMAINING(&flac->bs) / 8;
+	position -= flac->bs.unalignedByteCount;
+
+	/* adjust position if we provided the header */
+	if (position == 0)
+		return 0;
+	if (decoder->compressed_start == (const uint8_t *)(decoder->custom_header))
+		position -= decoder->compressed_length;
+
+	flac_decoder_free(decoder);
+	return position;
+}
+
+/*-------------------------------------------------
+ *  read_callback - handle reads from the input
+ *  stream
+ *-------------------------------------------------
+ */
+
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
+
+static size_t flac_decoder_read_callback(void *userdata, void *buffer, size_t bytes)
+{
+	flac_decoder* decoder = (flac_decoder*)userdata;
+	uint8_t *dst = buffer;
+
+	/* copy from primary buffer first */
+	uint32_t outputpos = 0;
+	if (outputpos < bytes && decoder->compressed_offset < decoder->compressed_length)
+	{
+		uint32_t bytes_to_copy = MIN(bytes - outputpos, decoder->compressed_length - decoder->compressed_offset);
+		memcpy(&dst[outputpos], decoder->compressed_start + decoder->compressed_offset, bytes_to_copy);
+		outputpos += bytes_to_copy;
+		decoder->compressed_offset += bytes_to_copy;
+	}
+
+	/* once we're out of that, copy from the secondary buffer */
+	if (outputpos < bytes && decoder->compressed_offset < decoder->compressed_length + decoder->compressed2_length)
+	{
+		uint32_t bytes_to_copy = MIN(bytes - outputpos, decoder->compressed2_length - (decoder->compressed_offset - decoder->compressed_length));
+		memcpy(&dst[outputpos], decoder->compressed2_start + decoder->compressed_offset - decoder->compressed_length, bytes_to_copy);
+		outputpos += bytes_to_copy;
+		decoder->compressed_offset += bytes_to_copy;
+	}
+
+	return outputpos;
+}
+
+/*-------------------------------------------------
+ *  metadata_callback - handle STREAMINFO metadata
+ *-------------------------------------------------
+ */
+
+static void flac_decoder_metadata_callback(void *userdata, drflac_metadata *metadata)
+{
+	flac_decoder *decoder = userdata;
+
+	/* ignore all but STREAMINFO metadata */
+	if (metadata->type != DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO)
+		return;
+
+	/* parse out the data we care about */
+	decoder->sample_rate = metadata->data.streaminfo.sampleRate;
+	decoder->bits_per_sample = metadata->data.streaminfo.bitsPerSample;
+	decoder->channels = metadata->data.streaminfo.channels;
+}
+
+/*-------------------------------------------------
+ *  write_callback - handle writes to the output
+ *  stream
+ *-------------------------------------------------
+ */
+
+static void flac_decoder_write_callback(void *userdata, void *buffer, size_t bytes)
+{
+	int sampnum, chan;
+	int shift, blocksize;
+	flac_decoder * decoder = (flac_decoder *)userdata;
+	int16_t *sampbuf = (int16_t *)buffer;
+	int sampch = channels(decoder);
+	uint32_t offset = decoder->uncompressed_offset;
+	uint16_t usample;
+
+	/* interleaved case */
+	shift = decoder->uncompressed_swap ? 8 : 0;
+	blocksize = bytes / (sampch * sizeof(sampbuf[0]));
+	if (decoder->uncompressed_start[1] == NULL)
+	{
+		int16_t *dest = decoder->uncompressed_start[0] + offset * sampch;
+		for (sampnum = 0; sampnum < blocksize && offset < decoder->uncompressed_length; sampnum++, offset++)
+			for (chan = 0; chan < sampch; chan++) {
+				usample = (uint16_t)*sampbuf++;
+				*dest++ = (int16_t)((usample << shift) | (usample >> shift));
+			}
+	}
+
+	/* non-interleaved case */
+	else
+	{
+		for (sampnum = 0; sampnum < blocksize && offset < decoder->uncompressed_length; sampnum++, offset++)
+			for (chan = 0; chan < sampch; chan++) {
+				usample = (uint16_t)*sampbuf++;
+				if (decoder->uncompressed_start[chan] != NULL)
+					decoder->uncompressed_start[chan][offset] = (int16_t) ((usample << shift) | (usample >> shift));
+			}
+	}
+	decoder->uncompressed_offset = offset;
+}
+
+
+/*-------------------------------------------------
+ *  seek_callback - handle seeks on the output
+ *  stream
+ *-------------------------------------------------
+ */
+
+static drflac_bool32 flac_decoder_seek_callback(void *userdata, int offset, drflac_seek_origin origin)
+{
+	flac_decoder * decoder = (flac_decoder *)userdata;
+	uint32_t length = decoder->compressed_length + decoder->compressed2_length;
+
+	if (origin == drflac_seek_origin_start) {
+		uint32_t pos = offset;
+		if (pos <= length) {
+			decoder->compressed_offset = pos;
+			return 1;
+		}
+	} else if (origin == drflac_seek_origin_current) {
+		uint32_t pos = decoder->compressed_offset + offset;
+		if (pos <= length) {
+			decoder->compressed_offset = pos;
+			return 1;
+		}
+	}
+	return 0;
+}
+
diff --git a/deps/libchdr/src/libchdr_huffman.c b/deps/libchdr/src/libchdr_huffman.c
new file mode 100644
index 0000000..6a50f13
--- /dev/null
+++ b/deps/libchdr/src/libchdr_huffman.c
@@ -0,0 +1,544 @@
+/* license:BSD-3-Clause
+ * copyright-holders:Aaron Giles
+****************************************************************************
+
+    huffman.c
+
+    Static Huffman compression and decompression helpers.
+
+****************************************************************************
+
+    Maximum codelength is officially (alphabetsize - 1). This would be 255 bits
+    (since we use 1 byte values). However, it is also dependent upon the number
+    of samples used, as follows:
+
+         2 bits -> 3..4 samples
+         3 bits -> 5..7 samples
+         4 bits -> 8..12 samples
+         5 bits -> 13..20 samples
+         6 bits -> 21..33 samples
+         7 bits -> 34..54 samples
+         8 bits -> 55..88 samples
+         9 bits -> 89..143 samples
+        10 bits -> 144..232 samples
+        11 bits -> 233..376 samples
+        12 bits -> 377..609 samples
+        13 bits -> 610..986 samples
+        14 bits -> 987..1596 samples
+        15 bits -> 1597..2583 samples
+        16 bits -> 2584..4180 samples   -> note that a 4k data size guarantees codelength <= 16 bits
+        17 bits -> 4181..6764 samples
+        18 bits -> 6765..10945 samples
+        19 bits -> 10946..17710 samples
+        20 bits -> 17711..28656 samples
+        21 bits -> 28657..46367 samples
+        22 bits -> 46368..75024 samples
+        23 bits -> 75025..121392 samples
+        24 bits -> 121393..196417 samples
+        25 bits -> 196418..317810 samples
+        26 bits -> 317811..514228 samples
+        27 bits -> 514229..832039 samples
+        28 bits -> 832040..1346268 samples
+        29 bits -> 1346269..2178308 samples
+        30 bits -> 2178309..3524577 samples
+        31 bits -> 3524578..5702886 samples
+        32 bits -> 5702887..9227464 samples
+
+    Looking at it differently, here is where powers of 2 fall into these buckets:
+
+          256 samples -> 11 bits max
+          512 samples -> 12 bits max
+           1k samples -> 14 bits max
+           2k samples -> 15 bits max
+           4k samples -> 16 bits max
+           8k samples -> 18 bits max
+          16k samples -> 19 bits max
+          32k samples -> 21 bits max
+          64k samples -> 22 bits max
+         128k samples -> 24 bits max
+         256k samples -> 25 bits max
+         512k samples -> 27 bits max
+           1M samples -> 28 bits max
+           2M samples -> 29 bits max
+           4M samples -> 31 bits max
+           8M samples -> 32 bits max
+
+****************************************************************************
+
+    Delta-RLE encoding works as follows:
+
+    Starting value is assumed to be 0. All data is encoded as a delta
+    from the previous value, such that final[i] = final[i - 1] + delta.
+    Long runs of 0s are RLE-encoded as follows:
+
+        0x100 = repeat count of 8
+        0x101 = repeat count of 9
+        0x102 = repeat count of 10
+        0x103 = repeat count of 11
+        0x104 = repeat count of 12
+        0x105 = repeat count of 13
+        0x106 = repeat count of 14
+        0x107 = repeat count of 15
+        0x108 = repeat count of 16
+        0x109 = repeat count of 32
+        0x10a = repeat count of 64
+        0x10b = repeat count of 128
+        0x10c = repeat count of 256
+        0x10d = repeat count of 512
+        0x10e = repeat count of 1024
+        0x10f = repeat count of 2048
+
+    Note that repeat counts are reset at the end of a row, so if a 0 run
+    extends to the end of a row, a large repeat count may be used.
+
+    The reason for starting the run counts at 8 is that 0 is expected to
+    be the most common symbol, and is typically encoded in 1 or 2 bits.
+
+***************************************************************************/
+
+#include <stdlib.h>
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <libchdr/huffman.h>
+
+#define MAX(x,y) ((x) > (y) ? (x) : (y))
+
+/***************************************************************************
+ *  MACROS
+ ***************************************************************************
+ */
+
+#define MAKE_LOOKUP(code,bits)  (((code) << 5) | ((bits) & 0x1f))
+
+/***************************************************************************
+ *  IMPLEMENTATION
+ ***************************************************************************
+ */
+
+/*-------------------------------------------------
+ *  huffman_context_base - create an encoding/
+ *  decoding context
+ *-------------------------------------------------
+ */
+
+struct huffman_decoder* create_huffman_decoder(int numcodes, int maxbits)
+{
+	struct huffman_decoder* decoder = NULL;
+
+	/* limit to 24 bits */
+	if (maxbits > 24)
+		return NULL;
+
+	decoder = (struct huffman_decoder*)malloc(sizeof(struct huffman_decoder));
+	decoder->numcodes = numcodes;
+	decoder->maxbits = maxbits;
+	decoder->lookup = (lookup_value*)malloc(sizeof(lookup_value) * (1 << maxbits));
+	decoder->huffnode = (struct node_t*)malloc(sizeof(struct node_t) * numcodes);
+	decoder->datahisto = NULL;
+	decoder->prevdata = 0;
+	decoder->rleremaining = 0;
+	return decoder;
+}
+
+void delete_huffman_decoder(struct huffman_decoder* decoder)
+{
+	if (decoder != NULL)
+	{
+		if (decoder->lookup != NULL)
+			free(decoder->lookup);
+		if (decoder->huffnode != NULL)
+			free(decoder->huffnode);
+		free(decoder);
+	}
+}
+
+/*-------------------------------------------------
+ *  decode_one - decode a single code from the
+ *  huffman stream
+ *-------------------------------------------------
+ */
+
+uint32_t huffman_decode_one(struct huffman_decoder* decoder, struct bitstream* bitbuf)
+{
+	/* peek ahead to get maxbits worth of data */
+	uint32_t bits = bitstream_peek(bitbuf, decoder->maxbits);
+
+	/* look it up, then remove the actual number of bits for this code */
+	lookup_value lookup = decoder->lookup[bits];
+	bitstream_remove(bitbuf, lookup & 0x1f);
+
+	/* return the value */
+	return lookup >> 5;
+}
+
+/*-------------------------------------------------
+ *  import_tree_rle - import an RLE-encoded
+ *  huffman tree from a source data stream
+ *-------------------------------------------------
+ */
+
+enum huffman_error huffman_import_tree_rle(struct huffman_decoder* decoder, struct bitstream* bitbuf)
+{
+	int numbits, curnode;
+	enum huffman_error error;
+
+	/* bits per entry depends on the maxbits */
+	if (decoder->maxbits >= 16)
+		numbits = 5;
+	else if (decoder->maxbits >= 8)
+		numbits = 4;
+	else
+		numbits = 3;
+
+	/* loop until we read all the nodes */
+	for (curnode = 0; curnode < decoder->numcodes; )
+	{
+		/* a non-one value is just raw */
+		int nodebits = bitstream_read(bitbuf, numbits);
+		if (nodebits != 1)
+			decoder->huffnode[curnode++].numbits = nodebits;
+
+		/* a one value is an escape code */
+		else
+		{
+			/* a double 1 is just a single 1 */
+			nodebits = bitstream_read(bitbuf, numbits);
+			if (nodebits == 1)
+				decoder->huffnode[curnode++].numbits = nodebits;
+
+			/* otherwise, we need one for value for the repeat count */
+			else
+			{
+				int repcount = bitstream_read(bitbuf, numbits) + 3;
+				while (repcount--)
+					decoder->huffnode[curnode++].numbits = nodebits;
+			}
+		}
+	}
+
+	/* make sure we ended up with the right number */
+	if (curnode != decoder->numcodes)
+		return HUFFERR_INVALID_DATA;
+
+	/* assign canonical codes for all nodes based on their code lengths */
+	error = huffman_assign_canonical_codes(decoder);
+	if (error != HUFFERR_NONE)
+		return error;
+
+	/* build the lookup table */
+	huffman_build_lookup_table(decoder);
+
+	/* determine final input length and report errors */
+	return bitstream_overflow(bitbuf) ? HUFFERR_INPUT_BUFFER_TOO_SMALL : HUFFERR_NONE;
+}
+
+
+/*-------------------------------------------------
+ *  import_tree_huffman - import a huffman-encoded
+ *  huffman tree from a source data stream
+ *-------------------------------------------------
+ */
+
+enum huffman_error huffman_import_tree_huffman(struct huffman_decoder* decoder, struct bitstream* bitbuf)
+{
+	int start;
+	int last = 0;
+	int count = 0;
+	int index;
+	int curcode;
+	uint8_t rlefullbits = 0;
+	uint32_t temp;
+	enum huffman_error error;
+	/* start by parsing the lengths for the small tree */
+	struct huffman_decoder* smallhuff = create_huffman_decoder(24, 6);
+	smallhuff->huffnode[0].numbits = bitstream_read(bitbuf, 3);
+	start = bitstream_read(bitbuf, 3) + 1;
+	for (index = 1; index < 24; index++)
+	{
+		if (index < start || count == 7)
+			smallhuff->huffnode[index].numbits = 0;
+		else
+		{
+			count = bitstream_read(bitbuf, 3);
+			smallhuff->huffnode[index].numbits = (count == 7) ? 0 : count;
+		}
+	}
+
+	/* then regenerate the tree */
+	error = huffman_assign_canonical_codes(smallhuff);
+	if (error != HUFFERR_NONE)
+		return error;
+	huffman_build_lookup_table(smallhuff);
+
+	/* determine the maximum length of an RLE count */
+	temp = decoder->numcodes - 9;
+	while (temp != 0)
+		temp >>= 1, rlefullbits++;
+
+	/* now process the rest of the data */
+	for (curcode = 0; curcode < decoder->numcodes; )
+	{
+		int value = huffman_decode_one(smallhuff, bitbuf);
+		if (value != 0)
+			decoder->huffnode[curcode++].numbits = last = value - 1;
+		else
+		{
+			int count = bitstream_read(bitbuf, 3) + 2;
+			if (count == 7+2)
+				count += bitstream_read(bitbuf, rlefullbits);
+			for ( ; count != 0 && curcode < decoder->numcodes; count--)
+				decoder->huffnode[curcode++].numbits = last;
+		}
+	}
+
+	/* make sure we ended up with the right number */
+	if (curcode != decoder->numcodes)
+		return HUFFERR_INVALID_DATA;
+
+	/* assign canonical codes for all nodes based on their code lengths */
+	error = huffman_assign_canonical_codes(decoder);
+	if (error != HUFFERR_NONE)
+		return error;
+
+	/* build the lookup table */
+	huffman_build_lookup_table(decoder);
+
+	/* determine final input length and report errors */
+	return bitstream_overflow(bitbuf) ? HUFFERR_INPUT_BUFFER_TOO_SMALL : HUFFERR_NONE;
+}
+
+/*-------------------------------------------------
+ *  compute_tree_from_histo - common backend for
+ *  computing a tree based on the data histogram
+ *-------------------------------------------------
+ */
+
+enum huffman_error huffman_compute_tree_from_histo(struct huffman_decoder* decoder)
+{
+	int i;
+	uint32_t lowerweight;
+	uint32_t upperweight;
+	/* compute the number of data items in the histogram */
+	uint32_t sdatacount = 0;
+	for (i = 0; i < decoder->numcodes; i++)
+		sdatacount += decoder->datahisto[i];
+
+	/* binary search to achieve the optimum encoding */
+	lowerweight = 0;
+	upperweight = sdatacount * 2;
+	while (1)
+	{
+		/* build a tree using the current weight */
+		uint32_t curweight = (upperweight + lowerweight) / 2;
+		int curmaxbits = huffman_build_tree(decoder, sdatacount, curweight);
+
+		/* apply binary search here */
+		if (curmaxbits <= decoder->maxbits)
+		{
+			lowerweight = curweight;
+
+			/* early out if it worked with the raw weights, or if we're done searching */
+			if (curweight == sdatacount || (upperweight - lowerweight) <= 1)
+				break;
+		}
+		else
+			upperweight = curweight;
+	}
+
+	/* assign canonical codes for all nodes based on their code lengths */
+	return huffman_assign_canonical_codes(decoder);
+}
+
+/***************************************************************************
+ *  INTERNAL FUNCTIONS
+ ***************************************************************************
+ */
+
+/*-------------------------------------------------
+ *  tree_node_compare - compare two tree nodes
+ *  by weight
+ *-------------------------------------------------
+ */
+
+static int huffman_tree_node_compare(const void *item1, const void *item2)
+{
+	const struct node_t *node1 = *(const struct node_t **)item1;
+	const struct node_t *node2 = *(const struct node_t **)item2;
+	if (node2->weight != node1->weight)
+		return node2->weight - node1->weight;
+	if (node2->bits - node1->bits == 0)
+		fprintf(stderr, "identical node sort keys, should not happen!\n");
+	return (int)node1->bits - (int)node2->bits;
+}
+
+/*-------------------------------------------------
+ *  build_tree - build a huffman tree based on the
+ *  data distribution
+ *-------------------------------------------------
+ */
+
+int huffman_build_tree(struct huffman_decoder* decoder, uint32_t totaldata, uint32_t totalweight)
+{
+	int curcode;
+	int nextalloc;
+	int listitems = 0;
+	int maxbits = 0;
+	/* make a list of all non-zero nodes */
+	struct node_t** list = (struct node_t**)malloc(sizeof(struct node_t*) * decoder->numcodes * 2);
+	memset(decoder->huffnode, 0, decoder->numcodes * sizeof(decoder->huffnode[0]));
+	for (curcode = 0; curcode < decoder->numcodes; curcode++)
+		if (decoder->datahisto[curcode] != 0)
+		{
+			list[listitems++] = &decoder->huffnode[curcode];
+			decoder->huffnode[curcode].count = decoder->datahisto[curcode];
+			decoder->huffnode[curcode].bits = curcode;
+
+			/* scale the weight by the current effective length, ensuring we don't go to 0 */
+			decoder->huffnode[curcode].weight = ((uint64_t)decoder->datahisto[curcode]) * ((uint64_t)totalweight) / ((uint64_t)totaldata);
+			if (decoder->huffnode[curcode].weight == 0)
+				decoder->huffnode[curcode].weight = 1;
+		}
+
+#if 0
+        fprintf(stderr, "Pre-sort:\n");
+        for (int i = 0; i < listitems; i++) {
+            fprintf(stderr, "weight: %d code: %d\n", list[i]->m_weight, list[i]->m_bits);
+        }
+#endif
+
+	/* sort the list by weight, largest weight first */
+	qsort(&list[0], listitems, sizeof(list[0]), huffman_tree_node_compare);
+
+#if 0
+        fprintf(stderr, "Post-sort:\n");
+        for (int i = 0; i < listitems; i++) {
+            fprintf(stderr, "weight: %d code: %d\n", list[i]->m_weight, list[i]->m_bits);
+        }
+        fprintf(stderr, "===================\n");
+#endif
+
+	/* now build the tree */
+	nextalloc = decoder->numcodes;
+	while (listitems > 1)
+	{
+		int curitem;
+		/* remove lowest two items */
+		struct node_t* node1 = &(*list[--listitems]);
+		struct node_t* node0 = &(*list[--listitems]);
+
+		/* create new node */
+		struct node_t* newnode = &decoder->huffnode[nextalloc++];
+		newnode->parent = NULL;
+		node0->parent = node1->parent = newnode;
+		newnode->weight = node0->weight + node1->weight;
+
+		/* insert into list at appropriate location */
+		for (curitem = 0; curitem < listitems; curitem++)
+			if (newnode->weight > list[curitem]->weight)
+			{
+				memmove(&list[curitem+1], &list[curitem], (listitems - curitem) * sizeof(list[0]));
+				break;
+			}
+		list[curitem] = newnode;
+		listitems++;
+	}
+
+	/* compute the number of bits in each code, and fill in another histogram */
+	for (curcode = 0; curcode < decoder->numcodes; curcode++)
+	{
+		struct node_t *curnode;
+		struct node_t* node = &decoder->huffnode[curcode];
+		node->numbits = 0;
+		node->bits = 0;
+
+		/* if we have a non-zero weight, compute the number of bits */
+		if (node->weight > 0)
+		{
+			/* determine the number of bits for this node */
+			for (curnode = node; curnode->parent != NULL; curnode = curnode->parent)
+				node->numbits++;
+			if (node->numbits == 0)
+				node->numbits = 1;
+
+			/* keep track of the max */
+			maxbits = MAX(maxbits, ((int)node->numbits));
+		}
+	}
+	return maxbits;
+}
+
+/*-------------------------------------------------
+ *  assign_canonical_codes - assign canonical codes
+ *  to all the nodes based on the number of bits
+ *  in each
+ *-------------------------------------------------
+ */
+
+enum huffman_error huffman_assign_canonical_codes(struct huffman_decoder* decoder)
+{
+	int curcode, codelen;
+	uint32_t curstart = 0;
+	/* build up a histogram of bit lengths */
+	uint32_t bithisto[33] = { 0 };
+	for (curcode = 0; curcode < decoder->numcodes; curcode++)
+	{
+		struct node_t* node = &decoder->huffnode[curcode];
+		if (node->numbits > decoder->maxbits)
+			return HUFFERR_INTERNAL_INCONSISTENCY;
+		if (node->numbits <= 32)
+			bithisto[node->numbits]++;
+	}
+
+	/* for each code length, determine the starting code number */
+	for (codelen = 32; codelen > 0; codelen--)
+	{
+		uint32_t nextstart = (curstart + bithisto[codelen]) >> 1;
+		if (codelen != 1 && nextstart * 2 != (curstart + bithisto[codelen]))
+			return HUFFERR_INTERNAL_INCONSISTENCY;
+		bithisto[codelen] = curstart;
+		curstart = nextstart;
+	}
+
+	/* now assign canonical codes */
+	for (curcode = 0; curcode < decoder->numcodes; curcode++)
+	{
+		struct node_t* node = &decoder->huffnode[curcode];
+		if (node->numbits > 0)
+			node->bits = bithisto[node->numbits]++;
+	}
+	return HUFFERR_NONE;
+}
+
+/*-------------------------------------------------
+ *  build_lookup_table - build a lookup table for
+ *  fast decoding
+ *-------------------------------------------------
+ */
+
+void huffman_build_lookup_table(struct huffman_decoder* decoder)
+{
+	int curcode;
+	/* iterate over all codes */
+	for (curcode = 0; curcode < decoder->numcodes; curcode++)
+	{
+		/* process all nodes which have non-zero bits */
+		struct node_t* node = &decoder->huffnode[curcode];
+		if (node->numbits > 0)
+		{
+         int shift;
+         lookup_value *dest;
+         lookup_value *destend;
+			/* set up the entry */
+			lookup_value value = MAKE_LOOKUP(curcode, node->numbits);
+
+			/* fill all matching entries */
+			shift = decoder->maxbits - node->numbits;
+			dest = &decoder->lookup[node->bits << shift];
+			destend = &decoder->lookup[((node->bits + 1) << shift) - 1];
+			while (dest <= destend)
+				*dest++ = value;
+		}
+	}
+}
author	jdgleaver	2021-03-15 15:36:34 +0000
committer	jdgleaver	2021-03-15 15:36:34 +0000
commit	2ff0b5124f2e17a290121e1eeecf45db1d9e2c85 (patch)
tree	3cf574af74146252926490c2816d95e34a602a3c /deps/libchdr/src
parent	e3e1b865f7c06f57918b97f7293b5b2959fb7b7d (diff)
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