aboutsummaryrefslogtreecommitdiff
path: root/deps/libchdr/huffman.h
diff options
context:
space:
mode:
Diffstat (limited to 'deps/libchdr/huffman.h')
-rw-r--r--deps/libchdr/huffman.h176
1 files changed, 89 insertions, 87 deletions
diff --git a/deps/libchdr/huffman.h b/deps/libchdr/huffman.h
index 71de399..8bcc45a 100644
--- a/deps/libchdr/huffman.h
+++ b/deps/libchdr/huffman.h
@@ -1,87 +1,89 @@
-// license:BSD-3-Clause
-// copyright-holders:Aaron Giles
-/***************************************************************************
-
- huffman.h
-
- Static Huffman compression and decompression helpers.
-
-***************************************************************************/
-
-#pragma once
-
-#ifndef __HUFFMAN_H__
-#define __HUFFMAN_H__
-
-#include "bitstream.h"
-
-
-//**************************************************************************
-// CONSTANTS
-//**************************************************************************
-
-enum huffman_error
-{
- HUFFERR_NONE = 0,
- HUFFERR_TOO_MANY_BITS,
- HUFFERR_INVALID_DATA,
- HUFFERR_INPUT_BUFFER_TOO_SMALL,
- HUFFERR_OUTPUT_BUFFER_TOO_SMALL,
- HUFFERR_INTERNAL_INCONSISTENCY,
- HUFFERR_TOO_MANY_CONTEXTS
-};
-
-
-
-//**************************************************************************
-// TYPE DEFINITIONS
-//**************************************************************************
-
-typedef uint16_t lookup_value;
-
-// a node in the huffman tree
-struct node_t
-{
- struct node_t* parent; // pointer to parent node
- uint32_t count; // number of hits on this node
- uint32_t weight; // assigned weight of this node
- uint32_t bits; // bits used to encode the node
- uint8_t numbits; // number of bits needed for this node
-};
-
-// ======================> huffman_context_base
-
-// context class for decoding
-struct huffman_decoder
-{
- // internal state
- uint32_t numcodes; // number of total codes being processed
- uint8_t maxbits; // maximum bits per code
- uint8_t prevdata; // value of the previous data (for delta-RLE encoding)
- int rleremaining; // number of RLE bytes remaining (for delta-RLE encoding)
- lookup_value * lookup; // pointer to the lookup table
- struct node_t * huffnode; // array of nodes
- uint32_t * datahisto; // histogram of data values
-
- // array versions of the info we need
- //node_t* huffnode_array; //[_NumCodes];
- //lookup_value* lookup_array; //[1 << _MaxBits];
-};
-
-// ======================> huffman_decoder
-
-struct huffman_decoder* create_huffman_decoder(int numcodes, int maxbits);
-
-// single item operations
-uint32_t huffman_decode_one(struct huffman_decoder* decoder, struct bitstream* bitbuf);
-
-enum huffman_error huffman_import_tree_rle(struct huffman_decoder* decoder, struct bitstream* bitbuf);
-enum huffman_error huffman_import_tree_huffman(struct huffman_decoder* decoder, struct bitstream* bitbuf);
-
-int huffman_build_tree(struct huffman_decoder* decoder, uint32_t totaldata, uint32_t totalweight);
-enum huffman_error huffman_assign_canonical_codes(struct huffman_decoder* decoder);
-enum huffman_error huffman_compute_tree_from_histo(struct huffman_decoder* decoder);
-
-void huffman_build_lookup_table(struct huffman_decoder* decoder);
-
-#endif
+/* license:BSD-3-Clause
+ * copyright-holders:Aaron Giles
+ ***************************************************************************
+
+ huffman.h
+
+ Static Huffman compression and decompression helpers.
+
+***************************************************************************/
+
+#pragma once
+
+#ifndef __HUFFMAN_H__
+#define __HUFFMAN_H__
+
+#include "bitstream.h"
+
+
+/***************************************************************************
+ * CONSTANTS
+ ***************************************************************************
+ */
+
+enum huffman_error
+{
+ HUFFERR_NONE = 0,
+ HUFFERR_TOO_MANY_BITS,
+ HUFFERR_INVALID_DATA,
+ HUFFERR_INPUT_BUFFER_TOO_SMALL,
+ HUFFERR_OUTPUT_BUFFER_TOO_SMALL,
+ HUFFERR_INTERNAL_INCONSISTENCY,
+ HUFFERR_TOO_MANY_CONTEXTS
+};
+
+/***************************************************************************
+ * TYPE DEFINITIONS
+ ***************************************************************************
+ */
+
+typedef uint16_t lookup_value;
+
+/* a node in the huffman tree */
+struct node_t
+{
+ struct node_t* parent; /* pointer to parent node */
+ uint32_t count; /* number of hits on this node */
+ uint32_t weight; /* assigned weight of this node */
+ uint32_t bits; /* bits used to encode the node */
+ uint8_t numbits; /* number of bits needed for this node */
+};
+
+/* ======================> huffman_context_base */
+
+/* context class for decoding */
+struct huffman_decoder
+{
+ /* internal state */
+ uint32_t numcodes; /* number of total codes being processed */
+ uint8_t maxbits; /* maximum bits per code */
+ uint8_t prevdata; /* value of the previous data (for delta-RLE encoding) */
+ int rleremaining; /* number of RLE bytes remaining (for delta-RLE encoding) */
+ lookup_value * lookup; /* pointer to the lookup table */
+ struct node_t * huffnode; /* array of nodes */
+ uint32_t * datahisto; /* histogram of data values */
+
+ /* array versions of the info we need */
+#if 0
+ node_t* huffnode_array; /* [_NumCodes]; */
+ lookup_value* lookup_array; /* [1 << _MaxBits]; */
+#endif
+};
+
+/* ======================> huffman_decoder */
+
+struct huffman_decoder* create_huffman_decoder(int numcodes, int maxbits);
+
+/* single item operations */
+uint32_t huffman_decode_one(struct huffman_decoder* decoder, struct bitstream* bitbuf);
+
+enum huffman_error huffman_import_tree_rle(struct huffman_decoder* decoder, struct bitstream* bitbuf);
+enum huffman_error huffman_import_tree_huffman(struct huffman_decoder* decoder, struct bitstream* bitbuf);
+
+int huffman_build_tree(struct huffman_decoder* decoder, uint32_t totaldata, uint32_t totalweight);
+enum huffman_error huffman_assign_canonical_codes(struct huffman_decoder* decoder);
+enum huffman_error huffman_compute_tree_from_histo(struct huffman_decoder* decoder);
+
+void huffman_build_lookup_table(struct huffman_decoder* decoder);
+
+#endif