summaryrefslogtreecommitdiff
path: root/src/libffmpeg/libavcodec/bitstream.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/libffmpeg/libavcodec/bitstream.c')
-rw-r--r--src/libffmpeg/libavcodec/bitstream.c254
1 files changed, 0 insertions, 254 deletions
diff --git a/src/libffmpeg/libavcodec/bitstream.c b/src/libffmpeg/libavcodec/bitstream.c
deleted file mode 100644
index 22d256df5..000000000
--- a/src/libffmpeg/libavcodec/bitstream.c
+++ /dev/null
@@ -1,254 +0,0 @@
-/*
- * Common bit i/o utils
- * Copyright (c) 2000, 2001 Fabrice Bellard.
- * Copyright (c) 2002-2004 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
- *
- * alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at>
- */
-
-/**
- * @file bitstream.c
- * bitstream api.
- */
-
-#include "avcodec.h"
-#include "bitstream.h"
-
-void align_put_bits(PutBitContext *s)
-{
-#ifdef ALT_BITSTREAM_WRITER
- put_bits(s,( - s->index) & 7,0);
-#else
- put_bits(s,s->bit_left & 7,0);
-#endif
-}
-
-void ff_put_string(PutBitContext * pbc, char *s, int put_zero)
-{
- while(*s){
- put_bits(pbc, 8, *s);
- s++;
- }
- if(put_zero)
- put_bits(pbc, 8, 0);
-}
-
-/* VLC decoding */
-
-//#define DEBUG_VLC
-
-#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) {
- vlc->table_allocated += (1 << vlc->bits);
- if(use_static)
- vlc->table = av_realloc_static(vlc->table,
- sizeof(VLC_TYPE) * 2 * vlc->table_allocated);
- else
- vlc->table = av_realloc(vlc->table,
- sizeof(VLC_TYPE) * 2 * vlc->table_allocated);
- if (!vlc->table)
- return -1;
- }
- return index;
-}
-
-static int build_table(VLC *vlc, int table_nb_bits,
- int nb_codes,
- const void *bits, int bits_wrap, int bits_size,
- const void *codes, int codes_wrap, int codes_size,
- uint32_t code_prefix, int n_prefix, int flags)
-{
- int i, j, k, n, table_size, table_index, nb, n1, index, code_prefix2;
- uint32_t code;
- VLC_TYPE (*table)[2];
-
- table_size = 1 << table_nb_bits;
- table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_STATIC);
-#ifdef DEBUG_VLC
- printf("new table index=%d size=%d code_prefix=%x n=%d\n",
- table_index, table_size, code_prefix, n_prefix);
-#endif
- 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 auxillary table sizes */
- for(i=0;i<nb_codes;i++) {
- GET_DATA(n, bits, i, bits_wrap, bits_size);
- GET_DATA(code, codes, i, codes_wrap, codes_size);
- /* we accept tables with holes */
- if (n <= 0)
- continue;
-#if defined(DEBUG_VLC) && 0
- printf("i=%d n=%d code=0x%x\n", i, n, code);
-#endif
- /* if code matches the prefix, it is in the table */
- n -= n_prefix;
- if(flags & INIT_VLC_LE)
- code_prefix2= code & (n_prefix>=32 ? 0xffffffff : (1 << n_prefix)-1);
- else
- code_prefix2= code >> n;
- if (n > 0 && code_prefix2 == code_prefix) {
- if (n <= table_nb_bits) {
- /* no need to add another table */
- j = (code << (table_nb_bits - n)) & (table_size - 1);
- nb = 1 << (table_nb_bits - n);
- for(k=0;k<nb;k++) {
- if(flags & INIT_VLC_LE)
- j = (code >> n_prefix) + (k<<n);
-#ifdef DEBUG_VLC
- av_log(NULL, AV_LOG_DEBUG, "%4x: code=%d n=%d\n",
- j, i, n);
-#endif
- 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] = i; //code
- j++;
- }
- } else {
- n -= table_nb_bits;
- j = (code >> ((flags & INIT_VLC_LE) ? n_prefix : n)) & ((1 << table_nb_bits) - 1);
-#ifdef DEBUG_VLC
- printf("%4x: n=%d (subtable)\n",
- j, n);
-#endif
- /* compute table size */
- n1 = -table[j][1]; //bits
- if (n > n1)
- n1 = n;
- table[j][1] = -n1; //bits
- }
- }
- }
-
- /* second pass : fill auxillary tables recursively */
- for(i=0;i<table_size;i++) {
- n = table[i][1]; //bits
- if (n < 0) {
- n = -n;
- if (n > table_nb_bits) {
- n = table_nb_bits;
- table[i][1] = -n; //bits
- }
- index = build_table(vlc, n, nb_codes,
- bits, bits_wrap, bits_size,
- codes, codes_wrap, codes_size,
- (flags & INIT_VLC_LE) ? (code_prefix | (i << n_prefix)) : ((code_prefix << table_nb_bits) | i),
- n_prefix + table_nb_bits, flags);
- if (index < 0)
- return -1;
- /* note: realloc has been done, so reload tables */
- table = &vlc->table[table_index];
- table[i][0] = index; //code
- }
- }
- 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.
-
- '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' and 'codes' tables.
-
- 'use_static' should be set to 1 for tables, which should be freed
- with av_free_static(), 0 if free_vlc() will be used.
-*/
-int init_vlc(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,
- int use_static)
-{
- vlc->bits = nb_bits;
- if(!use_static) {
- vlc->table = NULL;
- vlc->table_allocated = 0;
- vlc->table_size = 0;
- } else {
- /* Static tables are initially always NULL, return
- if vlc->table != NULL to avoid double allocation */
- if(vlc->table)
- return 0;
- }
-
-#ifdef DEBUG_VLC
- printf("build table nb_codes=%d\n", nb_codes);
-#endif
-
- if (build_table(vlc, nb_bits, nb_codes,
- bits, bits_wrap, bits_size,
- codes, codes_wrap, codes_size,
- 0, 0, use_static) < 0) {
- av_free(vlc->table);
- return -1;
- }
- return 0;
-}
-
-
-void free_vlc(VLC *vlc)
-{
- av_free(vlc->table);
-}
-
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-25 13:55:48 +0000