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Diffstat (limited to 'deps/flac-1.3.2/src/libFLAC/bitreader.c')
| -rw-r--r-- | deps/flac-1.3.2/src/libFLAC/bitreader.c | 1087 |
1 files changed, 1087 insertions, 0 deletions
diff --git a/deps/flac-1.3.2/src/libFLAC/bitreader.c b/deps/flac-1.3.2/src/libFLAC/bitreader.c new file mode 100644 index 0000000..ab62d41 --- /dev/null +++ b/deps/flac-1.3.2/src/libFLAC/bitreader.c @@ -0,0 +1,1087 @@ +/* libFLAC - Free Lossless Audio Codec library + * Copyright (C) 2000-2009 Josh Coalson + * Copyright (C) 2011-2016 Xiph.Org Foundation + * + * 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 of the Xiph.org Foundation 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``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 THE FOUNDATION OR + * CONTRIBUTORS 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. + */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <stdlib.h> +#include <string.h> +#include "private/bitmath.h" +#include "private/bitreader.h" +#include "private/crc.h" +#include "private/macros.h" +#include "FLAC/assert.h" +#include "share/compat.h" +#include "share/endswap.h" + +/* Things should be fastest when this matches the machine word size */ +/* WATCHOUT: if you change this you must also change the following #defines down to COUNT_ZERO_MSBS2 below to match */ +/* WATCHOUT: there are a few places where the code will not work unless brword is >= 32 bits wide */ +/* also, some sections currently only have fast versions for 4 or 8 bytes per word */ + +#if (ENABLE_64_BIT_WORDS == 0) + +typedef FLAC__uint32 brword; +#define FLAC__BYTES_PER_WORD 4 /* sizeof brword */ +#define FLAC__BITS_PER_WORD 32 +#define FLAC__WORD_ALL_ONES ((FLAC__uint32)0xffffffff) +/* SWAP_BE_WORD_TO_HOST swaps bytes in a brword (which is always big-endian) if necessary to match host byte order */ +#if WORDS_BIGENDIAN +#define SWAP_BE_WORD_TO_HOST(x) (x) +#else +#define SWAP_BE_WORD_TO_HOST(x) ENDSWAP_32(x) +#endif +/* counts the # of zero MSBs in a word */ +#define COUNT_ZERO_MSBS(word) FLAC__clz_uint32(word) +#define COUNT_ZERO_MSBS2(word) FLAC__clz2_uint32(word) + +#else + +typedef FLAC__uint64 brword; +#define FLAC__BYTES_PER_WORD 8 /* sizeof brword */ +#define FLAC__BITS_PER_WORD 64 +#define FLAC__WORD_ALL_ONES ((FLAC__uint64)FLAC__U64L(0xffffffffffffffff)) +/* SWAP_BE_WORD_TO_HOST swaps bytes in a brword (which is always big-endian) if necessary to match host byte order */ +#if WORDS_BIGENDIAN +#define SWAP_BE_WORD_TO_HOST(x) (x) +#else +#define SWAP_BE_WORD_TO_HOST(x) ENDSWAP_64(x) +#endif +/* counts the # of zero MSBs in a word */ +#define COUNT_ZERO_MSBS(word) FLAC__clz_uint64(word) +#define COUNT_ZERO_MSBS2(word) FLAC__clz2_uint64(word) + +#endif + +/* + * This should be at least twice as large as the largest number of words + * required to represent any 'number' (in any encoding) you are going to + * read. With FLAC this is on the order of maybe a few hundred bits. + * If the buffer is smaller than that, the decoder won't be able to read + * in a whole number that is in a variable length encoding (e.g. Rice). + * But to be practical it should be at least 1K bytes. + * + * Increase this number to decrease the number of read callbacks, at the + * expense of using more memory. Or decrease for the reverse effect, + * keeping in mind the limit from the first paragraph. The optimal size + * also depends on the CPU cache size and other factors; some twiddling + * may be necessary to squeeze out the best performance. + */ +static const unsigned FLAC__BITREADER_DEFAULT_CAPACITY = 65536u / FLAC__BITS_PER_WORD; /* in words */ + +struct FLAC__BitReader { + /* any partially-consumed word at the head will stay right-justified as bits are consumed from the left */ + /* any incomplete word at the tail will be left-justified, and bytes from the read callback are added on the right */ + brword *buffer; + unsigned capacity; /* in words */ + unsigned words; /* # of completed words in buffer */ + unsigned bytes; /* # of bytes in incomplete word at buffer[words] */ + unsigned consumed_words; /* #words ... */ + unsigned consumed_bits; /* ... + (#bits of head word) already consumed from the front of buffer */ + unsigned read_crc16; /* the running frame CRC */ + unsigned crc16_align; /* the number of bits in the current consumed word that should not be CRC'd */ + FLAC__BitReaderReadCallback read_callback; + void *client_data; +}; + +static inline void crc16_update_word_(FLAC__BitReader *br, brword word) +{ + register unsigned crc = br->read_crc16; +#if FLAC__BYTES_PER_WORD == 4 + switch(br->crc16_align) { + case 0: crc = FLAC__CRC16_UPDATE((unsigned)(word >> 24), crc); + case 8: crc = FLAC__CRC16_UPDATE((unsigned)((word >> 16) & 0xff), crc); + case 16: crc = FLAC__CRC16_UPDATE((unsigned)((word >> 8) & 0xff), crc); + case 24: br->read_crc16 = FLAC__CRC16_UPDATE((unsigned)(word & 0xff), crc); + } +#elif FLAC__BYTES_PER_WORD == 8 + switch(br->crc16_align) { + case 0: crc = FLAC__CRC16_UPDATE((unsigned)(word >> 56), crc); + case 8: crc = FLAC__CRC16_UPDATE((unsigned)((word >> 48) & 0xff), crc); + case 16: crc = FLAC__CRC16_UPDATE((unsigned)((word >> 40) & 0xff), crc); + case 24: crc = FLAC__CRC16_UPDATE((unsigned)((word >> 32) & 0xff), crc); + case 32: crc = FLAC__CRC16_UPDATE((unsigned)((word >> 24) & 0xff), crc); + case 40: crc = FLAC__CRC16_UPDATE((unsigned)((word >> 16) & 0xff), crc); + case 48: crc = FLAC__CRC16_UPDATE((unsigned)((word >> 8) & 0xff), crc); + case 56: br->read_crc16 = FLAC__CRC16_UPDATE((unsigned)(word & 0xff), crc); + } +#else + for( ; br->crc16_align < FLAC__BITS_PER_WORD; br->crc16_align += 8) + crc = FLAC__CRC16_UPDATE((unsigned)((word >> (FLAC__BITS_PER_WORD-8-br->crc16_align)) & 0xff), crc); + br->read_crc16 = crc; +#endif + br->crc16_align = 0; +} + +static FLAC__bool bitreader_read_from_client_(FLAC__BitReader *br) +{ + unsigned start, end; + size_t bytes; + FLAC__byte *target; + + /* first shift the unconsumed buffer data toward the front as much as possible */ + if(br->consumed_words > 0) { + start = br->consumed_words; + end = br->words + (br->bytes? 1:0); + memmove(br->buffer, br->buffer+start, FLAC__BYTES_PER_WORD * (end - start)); + + br->words -= start; + br->consumed_words = 0; + } + + /* + * set the target for reading, taking into account word alignment and endianness + */ + bytes = (br->capacity - br->words) * FLAC__BYTES_PER_WORD - br->bytes; + if(bytes == 0) + return false; /* no space left, buffer is too small; see note for FLAC__BITREADER_DEFAULT_CAPACITY */ + target = ((FLAC__byte*)(br->buffer+br->words)) + br->bytes; + + /* before reading, if the existing reader looks like this (say brword is 32 bits wide) + * bitstream : 11 22 33 44 55 br->words=1 br->bytes=1 (partial tail word is left-justified) + * buffer[BE]: 11 22 33 44 55 ?? ?? ?? (shown layed out as bytes sequentially in memory) + * buffer[LE]: 44 33 22 11 ?? ?? ?? 55 (?? being don't-care) + * ^^-------target, bytes=3 + * on LE machines, have to byteswap the odd tail word so nothing is + * overwritten: + */ +#if WORDS_BIGENDIAN +#else + if(br->bytes) + br->buffer[br->words] = SWAP_BE_WORD_TO_HOST(br->buffer[br->words]); +#endif + + /* now it looks like: + * bitstream : 11 22 33 44 55 br->words=1 br->bytes=1 + * buffer[BE]: 11 22 33 44 55 ?? ?? ?? + * buffer[LE]: 44 33 22 11 55 ?? ?? ?? + * ^^-------target, bytes=3 + */ + + /* read in the data; note that the callback may return a smaller number of bytes */ + if(!br->read_callback(target, &bytes, br->client_data)) + return false; + + /* after reading bytes 66 77 88 99 AA BB CC DD EE FF from the client: + * bitstream : 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF + * buffer[BE]: 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF ?? + * buffer[LE]: 44 33 22 11 55 66 77 88 99 AA BB CC DD EE FF ?? + * now have to byteswap on LE machines: + */ +#if WORDS_BIGENDIAN +#else + end = (br->words*FLAC__BYTES_PER_WORD + br->bytes + (unsigned)bytes + (FLAC__BYTES_PER_WORD-1)) / FLAC__BYTES_PER_WORD; + for(start = br->words; start < end; start++) + br->buffer[start] = SWAP_BE_WORD_TO_HOST(br->buffer[start]); +#endif + + /* now it looks like: + * bitstream : 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF + * buffer[BE]: 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF ?? + * buffer[LE]: 44 33 22 11 88 77 66 55 CC BB AA 99 ?? FF EE DD + * finally we'll update the reader values: + */ + end = br->words*FLAC__BYTES_PER_WORD + br->bytes + (unsigned)bytes; + br->words = end / FLAC__BYTES_PER_WORD; + br->bytes = end % FLAC__BYTES_PER_WORD; + + return true; +} + +/*********************************************************************** + * + * Class constructor/destructor + * + ***********************************************************************/ + +FLAC__BitReader *FLAC__bitreader_new(void) +{ + FLAC__BitReader *br = calloc(1, sizeof(FLAC__BitReader)); + + /* calloc() implies: + memset(br, 0, sizeof(FLAC__BitReader)); + br->buffer = 0; + br->capacity = 0; + br->words = br->bytes = 0; + br->consumed_words = br->consumed_bits = 0; + br->read_callback = 0; + br->client_data = 0; + */ + return br; +} + +void FLAC__bitreader_delete(FLAC__BitReader *br) +{ + FLAC__ASSERT(0 != br); + + FLAC__bitreader_free(br); + free(br); +} + +/*********************************************************************** + * + * Public class methods + * + ***********************************************************************/ + +FLAC__bool FLAC__bitreader_init(FLAC__BitReader *br, FLAC__BitReaderReadCallback rcb, void *cd) +{ + FLAC__ASSERT(0 != br); + + br->words = br->bytes = 0; + br->consumed_words = br->consumed_bits = 0; + br->capacity = FLAC__BITREADER_DEFAULT_CAPACITY; + br->buffer = malloc(sizeof(brword) * br->capacity); + if(br->buffer == 0) + return false; + br->read_callback = rcb; + br->client_data = cd; + + return true; +} + +void FLAC__bitreader_free(FLAC__BitReader *br) +{ + FLAC__ASSERT(0 != br); + + if(0 != br->buffer) + free(br->buffer); + br->buffer = 0; + br->capacity = 0; + br->words = br->bytes = 0; + br->consumed_words = br->consumed_bits = 0; + br->read_callback = 0; + br->client_data = 0; +} + +FLAC__bool FLAC__bitreader_clear(FLAC__BitReader *br) +{ + br->words = br->bytes = 0; + br->consumed_words = br->consumed_bits = 0; + return true; +} + +void FLAC__bitreader_dump(const FLAC__BitReader *br, FILE *out) +{ + unsigned i, j; + if(br == 0) { + fprintf(out, "bitreader is NULL\n"); + } + else { + fprintf(out, "bitreader: capacity=%u words=%u bytes=%u consumed: words=%u, bits=%u\n", br->capacity, br->words, br->bytes, br->consumed_words, br->consumed_bits); + + for(i = 0; i < br->words; i++) { + fprintf(out, "%08X: ", i); + for(j = 0; j < FLAC__BITS_PER_WORD; j++) + if(i < br->consumed_words || (i == br->consumed_words && j < br->consumed_bits)) + fprintf(out, "."); + else + fprintf(out, "%01u", br->buffer[i] & ((brword)1 << (FLAC__BITS_PER_WORD-j-1)) ? 1:0); + fprintf(out, "\n"); + } + if(br->bytes > 0) { + fprintf(out, "%08X: ", i); + for(j = 0; j < br->bytes*8; j++) + if(i < br->consumed_words || (i == br->consumed_words && j < br->consumed_bits)) + fprintf(out, "."); + else + fprintf(out, "%01u", br->buffer[i] & ((brword)1 << (br->bytes*8-j-1)) ? 1:0); + fprintf(out, "\n"); + } + } +} + +void FLAC__bitreader_reset_read_crc16(FLAC__BitReader *br, FLAC__uint16 seed) +{ + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + FLAC__ASSERT((br->consumed_bits & 7) == 0); + + br->read_crc16 = (unsigned)seed; + br->crc16_align = br->consumed_bits; +} + +FLAC__uint16 FLAC__bitreader_get_read_crc16(FLAC__BitReader *br) +{ + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + FLAC__ASSERT((br->consumed_bits & 7) == 0); + FLAC__ASSERT(br->crc16_align <= br->consumed_bits); + + /* CRC any tail bytes in a partially-consumed word */ + if(br->consumed_bits) { + const brword tail = br->buffer[br->consumed_words]; + for( ; br->crc16_align < br->consumed_bits; br->crc16_align += 8) + br->read_crc16 = FLAC__CRC16_UPDATE((unsigned)((tail >> (FLAC__BITS_PER_WORD-8-br->crc16_align)) & 0xff), br->read_crc16); + } + return br->read_crc16; +} + +inline FLAC__bool FLAC__bitreader_is_consumed_byte_aligned(const FLAC__BitReader *br) +{ + return ((br->consumed_bits & 7) == 0); +} + +inline unsigned FLAC__bitreader_bits_left_for_byte_alignment(const FLAC__BitReader *br) +{ + return 8 - (br->consumed_bits & 7); +} + +inline unsigned FLAC__bitreader_get_input_bits_unconsumed(const FLAC__BitReader *br) +{ + return (br->words-br->consumed_words)*FLAC__BITS_PER_WORD + br->bytes*8 - br->consumed_bits; +} + +FLAC__bool FLAC__bitreader_read_raw_uint32(FLAC__BitReader *br, FLAC__uint32 *val, unsigned bits) +{ + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + + FLAC__ASSERT(bits <= 32); + FLAC__ASSERT((br->capacity*FLAC__BITS_PER_WORD) * 2 >= bits); + FLAC__ASSERT(br->consumed_words <= br->words); + + /* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */ + FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32); + + if(bits == 0) { /* OPT: investigate if this can ever happen, maybe change to assertion */ + *val = 0; + return true; + } + + while((br->words-br->consumed_words)*FLAC__BITS_PER_WORD + br->bytes*8 - br->consumed_bits < bits) { + if(!bitreader_read_from_client_(br)) + return false; + } + if(br->consumed_words < br->words) { /* if we've not consumed up to a partial tail word... */ + /* OPT: taking out the consumed_bits==0 "else" case below might make things faster if less code allows the compiler to inline this function */ + if(br->consumed_bits) { + /* this also works when consumed_bits==0, it's just a little slower than necessary for that case */ + const unsigned n = FLAC__BITS_PER_WORD - br->consumed_bits; + const brword word = br->buffer[br->consumed_words]; + if(bits < n) { + *val = (FLAC__uint32)((word & (FLAC__WORD_ALL_ONES >> br->consumed_bits)) >> (n-bits)); /* The result has <= 32 non-zero bits */ + br->consumed_bits += bits; + return true; + } + /* (FLAC__BITS_PER_WORD - br->consumed_bits <= bits) ==> (FLAC__WORD_ALL_ONES >> br->consumed_bits) has no more than 'bits' non-zero bits */ + *val = (FLAC__uint32)(word & (FLAC__WORD_ALL_ONES >> br->consumed_bits)); + bits -= n; + crc16_update_word_(br, word); + br->consumed_words++; + br->consumed_bits = 0; + if(bits) { /* if there are still bits left to read, there have to be less than 32 so they will all be in the next word */ + *val <<= bits; + *val |= (FLAC__uint32)(br->buffer[br->consumed_words] >> (FLAC__BITS_PER_WORD-bits)); + br->consumed_bits = bits; + } + return true; + } + else { /* br->consumed_bits == 0 */ + const brword word = br->buffer[br->consumed_words]; + if(bits < FLAC__BITS_PER_WORD) { + *val = (FLAC__uint32)(word >> (FLAC__BITS_PER_WORD-bits)); + br->consumed_bits = bits; + return true; + } + /* at this point bits == FLAC__BITS_PER_WORD == 32; because of previous assertions, it can't be larger */ + *val = (FLAC__uint32)word; + crc16_update_word_(br, word); + br->consumed_words++; + return true; + } + } + else { + /* in this case we're starting our read at a partial tail word; + * the reader has guaranteed that we have at least 'bits' bits + * available to read, which makes this case simpler. + */ + /* OPT: taking out the consumed_bits==0 "else" case below might make things faster if less code allows the compiler to inline this function */ + if(br->consumed_bits) { + /* this also works when consumed_bits==0, it's just a little slower than necessary for that case */ + FLAC__ASSERT(br->consumed_bits + bits <= br->bytes*8); + *val = (FLAC__uint32)((br->buffer[br->consumed_words] & (FLAC__WORD_ALL_ONES >> br->consumed_bits)) >> (FLAC__BITS_PER_WORD-br->consumed_bits-bits)); + br->consumed_bits += bits; + return true; + } + else { + *val = (FLAC__uint32)(br->buffer[br->consumed_words] >> (FLAC__BITS_PER_WORD-bits)); + br->consumed_bits += bits; + return true; + } + } +} + +FLAC__bool FLAC__bitreader_read_raw_int32(FLAC__BitReader *br, FLAC__int32 *val, unsigned bits) +{ + FLAC__uint32 uval, mask; + /* OPT: inline raw uint32 code here, or make into a macro if possible in the .h file */ + if(!FLAC__bitreader_read_raw_uint32(br, &uval, bits)) + return false; + /* sign-extend *val assuming it is currently bits wide. */ + /* From: https://graphics.stanford.edu/~seander/bithacks.html#FixedSignExtend */ + mask = 1u << (bits - 1); + *val = (uval ^ mask) - mask; + return true; +} + +FLAC__bool FLAC__bitreader_read_raw_uint64(FLAC__BitReader *br, FLAC__uint64 *val, unsigned bits) +{ + FLAC__uint32 hi, lo; + + if(bits > 32) { + if(!FLAC__bitreader_read_raw_uint32(br, &hi, bits-32)) + return false; + if(!FLAC__bitreader_read_raw_uint32(br, &lo, 32)) + return false; + *val = hi; + *val <<= 32; + *val |= lo; + } + else { + if(!FLAC__bitreader_read_raw_uint32(br, &lo, bits)) + return false; + *val = lo; + } + return true; +} + +inline FLAC__bool FLAC__bitreader_read_uint32_little_endian(FLAC__BitReader *br, FLAC__uint32 *val) +{ + FLAC__uint32 x8, x32 = 0; + + /* this doesn't need to be that fast as currently it is only used for vorbis comments */ + + if(!FLAC__bitreader_read_raw_uint32(br, &x32, 8)) + return false; + + if(!FLAC__bitreader_read_raw_uint32(br, &x8, 8)) + return false; + x32 |= (x8 << 8); + + if(!FLAC__bitreader_read_raw_uint32(br, &x8, 8)) + return false; + x32 |= (x8 << 16); + + if(!FLAC__bitreader_read_raw_uint32(br, &x8, 8)) + return false; + x32 |= (x8 << 24); + + *val = x32; + return true; +} + +FLAC__bool FLAC__bitreader_skip_bits_no_crc(FLAC__BitReader *br, unsigned bits) +{ + /* + * OPT: a faster implementation is possible but probably not that useful + * since this is only called a couple of times in the metadata readers. + */ + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + + if(bits > 0) { + const unsigned n = br->consumed_bits & 7; + unsigned m; + FLAC__uint32 x; + + if(n != 0) { + m = flac_min(8-n, bits); + if(!FLAC__bitreader_read_raw_uint32(br, &x, m)) + return false; + bits -= m; + } + m = bits / 8; + if(m > 0) { + if(!FLAC__bitreader_skip_byte_block_aligned_no_crc(br, m)) + return false; + bits %= 8; + } + if(bits > 0) { + if(!FLAC__bitreader_read_raw_uint32(br, &x, bits)) + return false; + } + } + + return true; +} + +FLAC__bool FLAC__bitreader_skip_byte_block_aligned_no_crc(FLAC__BitReader *br, unsigned nvals) +{ + FLAC__uint32 x; + + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + FLAC__ASSERT(FLAC__bitreader_is_consumed_byte_aligned(br)); + + /* step 1: skip over partial head word to get word aligned */ + while(nvals && br->consumed_bits) { /* i.e. run until we read 'nvals' bytes or we hit the end of the head word */ + if(!FLAC__bitreader_read_raw_uint32(br, &x, 8)) + return false; + nvals--; + } + if(0 == nvals) + return true; + /* step 2: skip whole words in chunks */ + while(nvals >= FLAC__BYTES_PER_WORD) { + if(br->consumed_words < br->words) { + br->consumed_words++; + nvals -= FLAC__BYTES_PER_WORD; + } + else if(!bitreader_read_from_client_(br)) + return false; + } + /* step 3: skip any remainder from partial tail bytes */ + while(nvals) { + if(!FLAC__bitreader_read_raw_uint32(br, &x, 8)) + return false; + nvals--; + } + + return true; +} + +FLAC__bool FLAC__bitreader_read_byte_block_aligned_no_crc(FLAC__BitReader *br, FLAC__byte *val, unsigned nvals) +{ + FLAC__uint32 x; + + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + FLAC__ASSERT(FLAC__bitreader_is_consumed_byte_aligned(br)); + + /* step 1: read from partial head word to get word aligned */ + while(nvals && br->consumed_bits) { /* i.e. run until we read 'nvals' bytes or we hit the end of the head word */ + if(!FLAC__bitreader_read_raw_uint32(br, &x, 8)) + return false; + *val++ = (FLAC__byte)x; + nvals--; + } + if(0 == nvals) + return true; + /* step 2: read whole words in chunks */ + while(nvals >= FLAC__BYTES_PER_WORD) { + if(br->consumed_words < br->words) { + const brword word = br->buffer[br->consumed_words++]; +#if FLAC__BYTES_PER_WORD == 4 + val[0] = (FLAC__byte)(word >> 24); + val[1] = (FLAC__byte)(word >> 16); + val[2] = (FLAC__byte)(word >> 8); + val[3] = (FLAC__byte)word; +#elif FLAC__BYTES_PER_WORD == 8 + val[0] = (FLAC__byte)(word >> 56); + val[1] = (FLAC__byte)(word >> 48); + val[2] = (FLAC__byte)(word >> 40); + val[3] = (FLAC__byte)(word >> 32); + val[4] = (FLAC__byte)(word >> 24); + val[5] = (FLAC__byte)(word >> 16); + val[6] = (FLAC__byte)(word >> 8); + val[7] = (FLAC__byte)word; +#else + for(x = 0; x < FLAC__BYTES_PER_WORD; x++) + val[x] = (FLAC__byte)(word >> (8*(FLAC__BYTES_PER_WORD-x-1))); +#endif + val += FLAC__BYTES_PER_WORD; + nvals -= FLAC__BYTES_PER_WORD; + } + else if(!bitreader_read_from_client_(br)) + return false; + } + /* step 3: read any remainder from partial tail bytes */ + while(nvals) { + if(!FLAC__bitreader_read_raw_uint32(br, &x, 8)) + return false; + *val++ = (FLAC__byte)x; + nvals--; + } + + return true; +} + +FLAC__bool FLAC__bitreader_read_unary_unsigned(FLAC__BitReader *br, unsigned *val) +#if 0 /* slow but readable version */ +{ + unsigned bit; + + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + + *val = 0; + while(1) { + if(!FLAC__bitreader_read_bit(br, &bit)) + return false; + if(bit) + break; + else + *val++; + } + return true; +} +#else +{ + unsigned i; + + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + + *val = 0; + while(1) { + while(br->consumed_words < br->words) { /* if we've not consumed up to a partial tail word... */ + brword b = br->buffer[br->consumed_words] << br->consumed_bits; + if(b) { + i = COUNT_ZERO_MSBS(b); + *val += i; + i++; + br->consumed_bits += i; + if(br->consumed_bits >= FLAC__BITS_PER_WORD) { /* faster way of testing if(br->consumed_bits == FLAC__BITS_PER_WORD) */ + crc16_update_word_(br, br->buffer[br->consumed_words]); + br->consumed_words++; + br->consumed_bits = 0; + } + return true; + } + else { + *val += FLAC__BITS_PER_WORD - br->consumed_bits; + crc16_update_word_(br, br->buffer[br->consumed_words]); + br->consumed_words++; + br->consumed_bits = 0; + /* didn't find stop bit yet, have to keep going... */ + } + } + /* at this point we've eaten up all the whole words; have to try + * reading through any tail bytes before calling the read callback. + * this is a repeat of the above logic adjusted for the fact we + * don't have a whole word. note though if the client is feeding + * us data a byte at a time (unlikely), br->consumed_bits may not + * be zero. + */ + if(br->bytes*8 > br->consumed_bits) { + const unsigned end = br->bytes * 8; + brword b = (br->buffer[br->consumed_words] & (FLAC__WORD_ALL_ONES << (FLAC__BITS_PER_WORD-end))) << br->consumed_bits; + if(b) { + i = COUNT_ZERO_MSBS(b); + *val += i; + i++; + br->consumed_bits += i; + FLAC__ASSERT(br->consumed_bits < FLAC__BITS_PER_WORD); + return true; + } + else { + *val += end - br->consumed_bits; + br->consumed_bits = end; + FLAC__ASSERT(br->consumed_bits < FLAC__BITS_PER_WORD); + /* didn't find stop bit yet, have to keep going... */ + } + } + if(!bitreader_read_from_client_(br)) + return false; + } +} +#endif + +FLAC__bool FLAC__bitreader_read_rice_signed(FLAC__BitReader *br, int *val, unsigned parameter) +{ + FLAC__uint32 lsbs = 0, msbs = 0; + unsigned uval; + + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + FLAC__ASSERT(parameter <= 31); + + /* read the unary MSBs and end bit */ + if(!FLAC__bitreader_read_unary_unsigned(br, &msbs)) + return false; + + /* read the binary LSBs */ + if(!FLAC__bitreader_read_raw_uint32(br, &lsbs, parameter)) + return false; + + /* compose the value */ + uval = (msbs << parameter) | lsbs; + if(uval & 1) + *val = -((int)(uval >> 1)) - 1; + else + *val = (int)(uval >> 1); + + return true; +} + +/* this is by far the most heavily used reader call. it ain't pretty but it's fast */ +FLAC__bool FLAC__bitreader_read_rice_signed_block(FLAC__BitReader *br, int vals[], unsigned nvals, unsigned parameter) +{ + /* try and get br->consumed_words and br->consumed_bits into register; + * must remember to flush them back to *br before calling other + * bitreader functions that use them, and before returning */ + unsigned cwords, words, lsbs, msbs, x, y; + unsigned ucbits; /* keep track of the number of unconsumed bits in word */ + brword b; + int *val, *end; + + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + /* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */ + FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32); + FLAC__ASSERT(parameter < 32); + /* the above two asserts also guarantee that the binary part never straddles more than 2 words, so we don't have to loop to read it */ + + val = vals; + end = vals + nvals; + + if(parameter == 0) { + while(val < end) { + /* read the unary MSBs and end bit */ + if(!FLAC__bitreader_read_unary_unsigned(br, &msbs)) + return false; + + *val++ = (int)(msbs >> 1) ^ -(int)(msbs & 1); + } + + return true; + } + + FLAC__ASSERT(parameter > 0); + + cwords = br->consumed_words; + words = br->words; + + /* if we've not consumed up to a partial tail word... */ + if(cwords >= words) { + x = 0; + goto process_tail; + } + + ucbits = FLAC__BITS_PER_WORD - br->consumed_bits; + b = br->buffer[cwords] << br->consumed_bits; /* keep unconsumed bits aligned to left */ + + while(val < end) { + /* read the unary MSBs and end bit */ + x = y = COUNT_ZERO_MSBS2(b); + if(x == FLAC__BITS_PER_WORD) { + x = ucbits; + do { + /* didn't find stop bit yet, have to keep going... */ + crc16_update_word_(br, br->buffer[cwords++]); + if (cwords >= words) + goto incomplete_msbs; + b = br->buffer[cwords]; + y = COUNT_ZERO_MSBS2(b); + x += y; + } while(y == FLAC__BITS_PER_WORD); + } + b <<= y; + b <<= 1; /* account for stop bit */ + ucbits = (ucbits - x - 1) % FLAC__BITS_PER_WORD; + msbs = x; + + /* read the binary LSBs */ + x = (FLAC__uint32)(b >> (FLAC__BITS_PER_WORD - parameter)); /* parameter < 32, so we can cast to 32-bit unsigned */ + if(parameter <= ucbits) { + ucbits -= parameter; + b <<= parameter; + } else { + /* there are still bits left to read, they will all be in the next word */ + crc16_update_word_(br, br->buffer[cwords++]); + if (cwords >= words) + goto incomplete_lsbs; + b = br->buffer[cwords]; + ucbits += FLAC__BITS_PER_WORD - parameter; + x |= (FLAC__uint32)(b >> ucbits); + b <<= FLAC__BITS_PER_WORD - ucbits; + } + lsbs = x; + + /* compose the value */ + x = (msbs << parameter) | lsbs; + *val++ = (int)(x >> 1) ^ -(int)(x & 1); + + continue; + + /* at this point we've eaten up all the whole words */ +process_tail: + do { + if(0) { +incomplete_msbs: + br->consumed_bits = 0; + br->consumed_words = cwords; + } + + /* read the unary MSBs and end bit */ + if(!FLAC__bitreader_read_unary_unsigned(br, &msbs)) + return false; + msbs += x; + x = ucbits = 0; + + if(0) { +incomplete_lsbs: + br->consumed_bits = 0; + br->consumed_words = cwords; + } + + /* read the binary LSBs */ + if(!FLAC__bitreader_read_raw_uint32(br, &lsbs, parameter - ucbits)) + return false; + lsbs = x | lsbs; + + /* compose the value */ + x = (msbs << parameter) | lsbs; + *val++ = (int)(x >> 1) ^ -(int)(x & 1); + x = 0; + + cwords = br->consumed_words; + words = br->words; + ucbits = FLAC__BITS_PER_WORD - br->consumed_bits; + b = br->buffer[cwords] << br->consumed_bits; + } while(cwords >= words && val < end); + } + + if(ucbits == 0 && cwords < words) { + /* don't leave the head word with no unconsumed bits */ + crc16_update_word_(br, br->buffer[cwords++]); + ucbits = FLAC__BITS_PER_WORD; + } + + br->consumed_bits = FLAC__BITS_PER_WORD - ucbits; + br->consumed_words = cwords; + + return true; +} + +#if 0 /* UNUSED */ +FLAC__bool FLAC__bitreader_read_golomb_signed(FLAC__BitReader *br, int *val, unsigned parameter) +{ + FLAC__uint32 lsbs = 0, msbs = 0; + unsigned bit, uval, k; + + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + + k = FLAC__bitmath_ilog2(parameter); + + /* read the unary MSBs and end bit */ + if(!FLAC__bitreader_read_unary_unsigned(br, &msbs)) + return false; + + /* read the binary LSBs */ + if(!FLAC__bitreader_read_raw_uint32(br, &lsbs, k)) + return false; + + if(parameter == 1u<<k) { + /* compose the value */ + uval = (msbs << k) | lsbs; + } + else { + unsigned d = (1 << (k+1)) - parameter; + if(lsbs >= d) { + if(!FLAC__bitreader_read_bit(br, &bit)) + return false; + lsbs <<= 1; + lsbs |= bit; + lsbs -= d; + } + /* compose the value */ + uval = msbs * parameter + lsbs; + } + + /* unfold unsigned to signed */ + if(uval & 1) + *val = -((int)(uval >> 1)) - 1; + else + *val = (int)(uval >> 1); + + return true; +} + +FLAC__bool FLAC__bitreader_read_golomb_unsigned(FLAC__BitReader *br, unsigned *val, unsigned parameter) +{ + FLAC__uint32 lsbs, msbs = 0; + unsigned bit, k; + + FLAC__ASSERT(0 != br); + FLAC__ASSERT(0 != br->buffer); + + k = FLAC__bitmath_ilog2(parameter); + + /* read the unary MSBs and end bit */ + if(!FLAC__bitreader_read_unary_unsigned(br, &msbs)) + return false; + + /* read the binary LSBs */ + if(!FLAC__bitreader_read_raw_uint32(br, &lsbs, k)) + return false; + + if(parameter == 1u<<k) { + /* compose the value */ + *val = (msbs << k) | lsbs; + } + else { + unsigned d = (1 << (k+1)) - parameter; + if(lsbs >= d) { + if(!FLAC__bitreader_read_bit(br, &bit)) + return false; + lsbs <<= 1; + lsbs |= bit; + lsbs -= d; + } + /* compose the value */ + *val = msbs * parameter + lsbs; + } + + return true; +} +#endif /* UNUSED */ + +/* on return, if *val == 0xffffffff then the utf-8 sequence was invalid, but the return value will be true */ +FLAC__bool FLAC__bitreader_read_utf8_uint32(FLAC__BitReader *br, FLAC__uint32 *val, FLAC__byte *raw, unsigned *rawlen) +{ + FLAC__uint32 v = 0; + FLAC__uint32 x; + unsigned i; + + if(!FLAC__bitreader_read_raw_uint32(br, &x, 8)) + return false; + if(raw) + raw[(*rawlen)++] = (FLAC__byte)x; + if(!(x & 0x80)) { /* 0xxxxxxx */ + v = x; + i = 0; + } + else if(x & 0xC0 && !(x & 0x20)) { /* 110xxxxx */ + v = x & 0x1F; + i = 1; + } + else if(x & 0xE0 && !(x & 0x10)) { /* 1110xxxx */ + v = x & 0x0F; + i = 2; + } + else if(x & 0xF0 && !(x & 0x08)) { /* 11110xxx */ + v = x & 0x07; + i = 3; + } + else if(x & 0xF8 && !(x & 0x04)) { /* 111110xx */ + v = x & 0x03; + i = 4; + } + else if(x & 0xFC && !(x & 0x02)) { /* 1111110x */ + v = x & 0x01; + i = 5; + } + else { + *val = 0xffffffff; + return true; + } + for( ; i; i--) { + if(!FLAC__bitreader_read_raw_uint32(br, &x, 8)) + return false; + if(raw) + raw[(*rawlen)++] = (FLAC__byte)x; + if(!(x & 0x80) || (x & 0x40)) { /* 10xxxxxx */ + *val = 0xffffffff; + return true; + } + v <<= 6; + v |= (x & 0x3F); + } + *val = v; + return true; +} + +/* on return, if *val == 0xffffffffffffffff then the utf-8 sequence was invalid, but the return value will be true */ +FLAC__bool FLAC__bitreader_read_utf8_uint64(FLAC__BitReader *br, FLAC__uint64 *val, FLAC__byte *raw, unsigned *rawlen) +{ + FLAC__uint64 v = 0; + FLAC__uint32 x; + unsigned i; + + if(!FLAC__bitreader_read_raw_uint32(br, &x, 8)) + return false; + if(raw) + raw[(*rawlen)++] = (FLAC__byte)x; + if(!(x & 0x80)) { /* 0xxxxxxx */ + v = x; + i = 0; + } + else if(x & 0xC0 && !(x & 0x20)) { /* 110xxxxx */ + v = x & 0x1F; + i = 1; + } + else if(x & 0xE0 && !(x & 0x10)) { /* 1110xxxx */ + v = x & 0x0F; + i = 2; + } + else if(x & 0xF0 && !(x & 0x08)) { /* 11110xxx */ + v = x & 0x07; + i = 3; + } + else if(x & 0xF8 && !(x & 0x04)) { /* 111110xx */ + v = x & 0x03; + i = 4; + } + else if(x & 0xFC && !(x & 0x02)) { /* 1111110x */ + v = x & 0x01; + i = 5; + } + else if(x & 0xFE && !(x & 0x01)) { /* 11111110 */ + v = 0; + i = 6; + } + else { + *val = FLAC__U64L(0xffffffffffffffff); + return true; + } + for( ; i; i--) { + if(!FLAC__bitreader_read_raw_uint32(br, &x, 8)) + return false; + if(raw) + raw[(*rawlen)++] = (FLAC__byte)x; + if(!(x & 0x80) || (x & 0x40)) { /* 10xxxxxx */ + *val = FLAC__U64L(0xffffffffffffffff); + return true; + } + v <<= 6; + v |= (x & 0x3F); + } + *val = v; + return true; +} + +/* These functions are declared inline in this file but are also callable as + * externs from elsewhere. + * According to the C99 spec, section 6.7.4, simply providing a function + * prototype in a header file without 'inline' and making the function inline + * in this file should be sufficient. + * Unfortunately, the Microsoft VS compiler doesn't pick them up externally. To + * fix that we add extern declarations here. + */ +extern FLAC__bool FLAC__bitreader_is_consumed_byte_aligned(const FLAC__BitReader *br); +extern unsigned FLAC__bitreader_bits_left_for_byte_alignment(const FLAC__BitReader *br); +extern unsigned FLAC__bitreader_get_input_bits_unconsumed(const FLAC__BitReader *br); +extern FLAC__bool FLAC__bitreader_read_uint32_little_endian(FLAC__BitReader *br, FLAC__uint32 *val); |