summaryrefslogtreecommitdiff
path: root/ffmpeg1/libavcodec/bitstream.c
diff options
context:
space:
mode:
Diffstat (limited to 'ffmpeg1/libavcodec/bitstream.c')
-rw-r--r--ffmpeg1/libavcodec/bitstream.c339
1 files changed, 0 insertions, 339 deletions
diff --git a/ffmpeg1/libavcodec/bitstream.c b/ffmpeg1/libavcodec/bitstream.c
deleted file mode 100644
index 6bcdadb..0000000
--- a/ffmpeg1/libavcodec/bitstream.c
+++ /dev/null
@@ -1,339 +0,0 @@
-/*
- * Common bit i/o utils
- * Copyright (c) 2000, 2001 Fabrice Bellard
- * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
- * Copyright (c) 2010 Loren Merritt
- *
- * alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at>
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/**
- * @file
- * bitstream api.
- */
-
-#include "libavutil/avassert.h"
-#include "avcodec.h"
-#include "mathops.h"
-#include "get_bits.h"
-#include "put_bits.h"
-
-const uint8_t ff_log2_run[41]={
- 0, 0, 0, 0, 1, 1, 1, 1,
- 2, 2, 2, 2, 3, 3, 3, 3,
- 4, 4, 5, 5, 6, 6, 7, 7,
- 8, 9,10,11,12,13,14,15,
-16,17,18,19,20,21,22,23,
-24,
-};
-
-void avpriv_align_put_bits(PutBitContext *s)
-{
- put_bits(s,s->bit_left & 7,0);
-}
-
-void avpriv_put_string(PutBitContext *pb, const char *string, int terminate_string)
-{
- while(*string){
- put_bits(pb, 8, *string);
- string++;
- }
- if(terminate_string)
- put_bits(pb, 8, 0);
-}
-
-void avpriv_copy_bits(PutBitContext *pb, const uint8_t *src, int length)
-{
- int words= length>>4;
- int bits= length&15;
- int i;
-
- if(length==0) return;
-
- if(CONFIG_SMALL || words < 16 || put_bits_count(pb)&7){
- for(i=0; i<words; i++) put_bits(pb, 16, AV_RB16(src + 2*i));
- }else{
- for(i=0; put_bits_count(pb)&31; i++)
- put_bits(pb, 8, src[i]);
- flush_put_bits(pb);
- memcpy(put_bits_ptr(pb), src+i, 2*words-i);
- skip_put_bytes(pb, 2*words-i);
- }
-
- put_bits(pb, bits, AV_RB16(src + 2*words)>>(16-bits));
-}
-
-/* VLC decoding */
-
-#define GET_DATA(v, table, i, wrap, size) \
-{\
- const uint8_t *ptr = (const uint8_t *)table + i * wrap;\
- switch(size) {\
- case 1:\
- v = *(const uint8_t *)ptr;\
- break;\
- case 2:\
- v = *(const uint16_t *)ptr;\
- break;\
- default:\
- v = *(const uint32_t *)ptr;\
- break;\
- }\
-}
-
-
-static int alloc_table(VLC *vlc, int size, int use_static)
-{
- int index;
- index = vlc->table_size;
- vlc->table_size += size;
- if (vlc->table_size > vlc->table_allocated) {
- if(use_static)
- abort(); // cannot do anything, init_vlc() is used with too little memory
- vlc->table_allocated += (1 << vlc->bits);
- vlc->table = av_realloc_f(vlc->table,
- vlc->table_allocated, sizeof(VLC_TYPE) * 2);
- if (!vlc->table)
- return -1;
- }
- return index;
-}
-
-static av_always_inline uint32_t bitswap_32(uint32_t x) {
- return (uint32_t)ff_reverse[x&0xFF]<<24
- | (uint32_t)ff_reverse[(x>>8)&0xFF]<<16
- | (uint32_t)ff_reverse[(x>>16)&0xFF]<<8
- | (uint32_t)ff_reverse[x>>24];
-}
-
-typedef struct {
- uint8_t bits;
- uint16_t symbol;
- /** codeword, with the first bit-to-be-read in the msb
- * (even if intended for a little-endian bitstream reader) */
- uint32_t code;
-} VLCcode;
-
-static int compare_vlcspec(const void *a, const void *b)
-{
- const VLCcode *sa=a, *sb=b;
- return (sa->code >> 1) - (sb->code >> 1);
-}
-
-/**
- * Build VLC decoding tables suitable for use with get_vlc().
- *
- * @param vlc the context to be initted
- *
- * @param table_nb_bits max length of vlc codes to store directly in this table
- * (Longer codes are delegated to subtables.)
- *
- * @param nb_codes number of elements in codes[]
- *
- * @param codes descriptions of the vlc codes
- * These must be ordered such that codes going into the same subtable are contiguous.
- * Sorting by VLCcode.code is sufficient, though not necessary.
- */
-static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
- VLCcode *codes, int flags)
-{
- int table_size, table_index, index, code_prefix, symbol, subtable_bits;
- int i, j, k, n, nb, inc;
- uint32_t code;
- VLC_TYPE (*table)[2];
-
- table_size = 1 << table_nb_bits;
- if (table_nb_bits > 30)
- return -1;
- table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_NEW_STATIC);
- av_dlog(NULL, "new table index=%d size=%d\n", table_index, table_size);
- if (table_index < 0)
- return -1;
- table = &vlc->table[table_index];
-
- for (i = 0; i < table_size; i++) {
- table[i][1] = 0; //bits
- table[i][0] = -1; //codes
- }
-
- /* first pass: map codes and compute auxiliary table sizes */
- for (i = 0; i < nb_codes; i++) {
- n = codes[i].bits;
- code = codes[i].code;
- symbol = codes[i].symbol;
- av_dlog(NULL, "i=%d n=%d code=0x%x\n", i, n, code);
- if (n <= table_nb_bits) {
- /* no need to add another table */
- j = code >> (32 - table_nb_bits);
- nb = 1 << (table_nb_bits - n);
- inc = 1;
- if (flags & INIT_VLC_LE) {
- j = bitswap_32(code);
- inc = 1 << n;
- }
- for (k = 0; k < nb; k++) {
- av_dlog(NULL, "%4x: code=%d n=%d\n", j, i, n);
- if (table[j][1] /*bits*/ != 0) {
- av_log(NULL, AV_LOG_ERROR, "incorrect codes\n");
- return -1;
- }
- table[j][1] = n; //bits
- table[j][0] = symbol;
- j += inc;
- }
- } else {
- /* fill auxiliary table recursively */
- n -= table_nb_bits;
- code_prefix = code >> (32 - table_nb_bits);
- subtable_bits = n;
- codes[i].bits = n;
- codes[i].code = code << table_nb_bits;
- for (k = i+1; k < nb_codes; k++) {
- n = codes[k].bits - table_nb_bits;
- if (n <= 0)
- break;
- code = codes[k].code;
- if (code >> (32 - table_nb_bits) != code_prefix)
- break;
- codes[k].bits = n;
- codes[k].code = code << table_nb_bits;
- subtable_bits = FFMAX(subtable_bits, n);
- }
- subtable_bits = FFMIN(subtable_bits, table_nb_bits);
- j = (flags & INIT_VLC_LE) ? bitswap_32(code_prefix) >> (32 - table_nb_bits) : code_prefix;
- table[j][1] = -subtable_bits;
- av_dlog(NULL, "%4x: n=%d (subtable)\n",
- j, codes[i].bits + table_nb_bits);
- index = build_table(vlc, subtable_bits, k-i, codes+i, flags);
- if (index < 0)
- return -1;
- /* note: realloc has been done, so reload tables */
- table = &vlc->table[table_index];
- table[j][0] = index; //code
- i = k-1;
- }
- }
- return table_index;
-}
-
-
-/* Build VLC decoding tables suitable for use with get_vlc().
-
- 'nb_bits' set thee decoding table size (2^nb_bits) entries. The
- bigger it is, the faster is the decoding. But it should not be too
- big to save memory and L1 cache. '9' is a good compromise.
-
- 'nb_codes' : number of vlcs codes
-
- 'bits' : table which gives the size (in bits) of each vlc code.
-
- 'codes' : table which gives the bit pattern of of each vlc code.
-
- 'symbols' : table which gives the values to be returned from get_vlc().
-
- 'xxx_wrap' : give the number of bytes between each entry of the
- 'bits' or 'codes' tables.
-
- 'xxx_size' : gives the number of bytes of each entry of the 'bits'
- or 'codes' tables.
-
- 'wrap' and 'size' allows to use any memory configuration and types
- (byte/word/long) to store the 'bits', 'codes', and 'symbols' tables.
-
- 'use_static' should be set to 1 for tables, which should be freed
- with av_free_static(), 0 if ff_free_vlc() will be used.
-*/
-int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
- const void *bits, int bits_wrap, int bits_size,
- const void *codes, int codes_wrap, int codes_size,
- const void *symbols, int symbols_wrap, int symbols_size,
- int flags)
-{
- VLCcode *buf;
- int i, j, ret;
-
- vlc->bits = nb_bits;
- if(flags & INIT_VLC_USE_NEW_STATIC){
- VLC dyn_vlc = *vlc;
-
- if (vlc->table_size)
- return 0;
-
- ret = ff_init_vlc_sparse(&dyn_vlc, nb_bits, nb_codes,
- bits, bits_wrap, bits_size,
- codes, codes_wrap, codes_size,
- symbols, symbols_wrap, symbols_size,
- flags & ~INIT_VLC_USE_NEW_STATIC);
- av_assert0(ret >= 0);
- av_assert0(dyn_vlc.table_size <= vlc->table_allocated);
- if(dyn_vlc.table_size < vlc->table_allocated)
- av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", dyn_vlc.table_size, vlc->table_allocated);
- memcpy(vlc->table, dyn_vlc.table, dyn_vlc.table_size * sizeof(*vlc->table));
- vlc->table_size = dyn_vlc.table_size;
- ff_free_vlc(&dyn_vlc);
- return 0;
- }else {
- vlc->table = NULL;
- vlc->table_allocated = 0;
- vlc->table_size = 0;
- }
-
- av_dlog(NULL, "build table nb_codes=%d\n", nb_codes);
-
- buf = av_malloc((nb_codes+1)*sizeof(VLCcode));
-
- av_assert0(symbols_size <= 2 || !symbols);
- j = 0;
-#define COPY(condition)\
- for (i = 0; i < nb_codes; i++) {\
- GET_DATA(buf[j].bits, bits, i, bits_wrap, bits_size);\
- if (!(condition))\
- continue;\
- GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size);\
- if (flags & INIT_VLC_LE)\
- buf[j].code = bitswap_32(buf[j].code);\
- else\
- buf[j].code <<= 32 - buf[j].bits;\
- if (symbols)\
- GET_DATA(buf[j].symbol, symbols, i, symbols_wrap, symbols_size)\
- else\
- buf[j].symbol = i;\
- j++;\
- }
- COPY(buf[j].bits > nb_bits);
- // qsort is the slowest part of init_vlc, and could probably be improved or avoided
- qsort(buf, j, sizeof(VLCcode), compare_vlcspec);
- COPY(buf[j].bits && buf[j].bits <= nb_bits);
- nb_codes = j;
-
- ret = build_table(vlc, nb_bits, nb_codes, buf, flags);
-
- av_free(buf);
- if (ret < 0) {
- av_freep(&vlc->table);
- return -1;
- }
- return 0;
-}
-
-
-void ff_free_vlc(VLC *vlc)
-{
- av_freep(&vlc->table);
-}
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-06 21:12:53 +0000