diff options
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, 0 insertions, 1087 deletions
diff --git a/deps/flac-1.3.2/src/libFLAC/bitreader.c b/deps/flac-1.3.2/src/libFLAC/bitreader.c deleted file mode 100644 index ab62d41..0000000 --- a/deps/flac-1.3.2/src/libFLAC/bitreader.c +++ /dev/null @@ -1,1087 +0,0 @@ -/* 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); |