X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fbitstream.c;h=93047a2b9109b648161a380ce2a49dd523106b7b;hb=6b3ef7f080293956b2e5212b83135c6b051212e9;hp=067a58b836e87f4ee08f465e675a7549c5da2418;hpb=3224079956811c29f6698235122b593e2d520343;p=ffmpeg diff --git a/libavcodec/bitstream.c b/libavcodec/bitstream.c index 067a58b836e..93047a2b910 100644 --- a/libavcodec/bitstream.c +++ b/libavcodec/bitstream.c @@ -6,125 +6,131 @@ * * alternative bitstream reader & writer by Michael Niedermayer * - * This file is part of FFmpeg. + * This file is part of Libav. * - * FFmpeg is free software; you can redistribute it and/or + * Libav 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, + * Libav 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 + * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** - * @file libavcodec/bitstream.c + * @file * bitstream api. */ #include "avcodec.h" +#include "internal.h" +#include "mathops.h" #include "get_bits.h" #include "put_bits.h" -const uint8_t ff_log2_run[32]={ +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 + 8, 9,10,11,12,13,14,15, +16,17,18,19,20,21,22,23, +24, }; -void align_put_bits(PutBitContext *s) +void avpriv_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 + put_bits(s, s->bit_left & 7, 0); } -void ff_put_string(PutBitContext *pb, const char *string, int terminate_string) +void avpriv_put_string(PutBitContext *pb, const char *string, + int terminate_string) { - while(*string){ + while (*string) { put_bits(pb, 8, *string); string++; } - if(terminate_string) + if (terminate_string) put_bits(pb, 8, 0); } -void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length) +void avpriv_copy_bits(PutBitContext *pb, const uint8_t *src, int length) { - int words= length>>4; - int bits= length&15; + int words = length >> 4; + int bits = length & 15; int i; - if(length==0) return; + if (length == 0) + return; - if(CONFIG_SMALL || words < 16 || put_bits_count(pb)&7){ - for(i=0; i>(16-bits)); + put_bits(pb, bits, AV_RB16(src + 2 * words) >> (16 - bits)); } /* 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;\ - }\ +#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; + int index = vlc->table_size; + vlc->table_size += size; if (vlc->table_size > vlc->table_allocated) { - if(use_static) - abort(); //cant do anything, init_vlc() is used with too little memory + int err; + if (use_static) + return AVERROR_BUG; vlc->table_allocated += (1 << vlc->bits); - vlc->table = av_realloc(vlc->table, - sizeof(VLC_TYPE) * 2 * vlc->table_allocated); - if (!vlc->table) - return -1; + if ((err = av_reallocp(&vlc->table, + sizeof(VLC_TYPE) * 2 * + vlc->table_allocated)) < 0) { + vlc->table_allocated = 0; + vlc->table_size = 0; + return err; + } } return index; } -static av_always_inline uint32_t bitswap_32(uint32_t x) { - return av_reverse[x&0xFF]<<24 - | av_reverse[(x>>8)&0xFF]<<16 - | av_reverse[(x>>16)&0xFF]<<8 - | av_reverse[x>>24]; +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 { +typedef struct VLCcode { uint8_t bits; uint16_t symbol; /** codeword, with the first bit-to-be-read in the msb @@ -134,10 +140,9 @@ typedef struct { static int compare_vlcspec(const void *a, const void *b) { - const VLCcode *sa=a, *sb=b; + const VLCcode *sa = a, *sb = b; return (sa->code >> 1) - (sb->code >> 1); } - /** * Build VLC decoding tables suitable for use with get_vlc(). * @@ -162,82 +167,72 @@ static int build_table(VLC *vlc, int table_nb_bits, int nb_codes, table_size = 1 << table_nb_bits; table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_NEW_STATIC); -#ifdef DEBUG_VLC - av_log(NULL,AV_LOG_DEBUG,"new table index=%d size=%d\n", - table_index, table_size); -#endif + ff_dlog(NULL, "new table index=%d size=%d\n", table_index, table_size); if (table_index < 0) - return -1; + return table_index; table = &vlc->table[table_index]; - for(i=0;i> (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> (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; -#ifdef DEBUG_VLC - av_log(NULL,AV_LOG_DEBUG,"%4x: n=%d (subtable)\n", - j, codes[i].bits + table_nb_bits); -#endif - 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; + ff_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++) { + ff_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 AVERROR_INVALIDDATA; } + 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; + ff_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 index; + /* note: realloc has been done, so reload tables */ + table = &vlc->table[table_index]; + table[j][0] = index; //code + i = k-1; + } } return table_index; } @@ -267,51 +262,53 @@ static int build_table(VLC *vlc, int table_nb_bits, int nb_codes, (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 free_vlc() will be used. + with av_free_static(), 0 if ff_free_vlc() will be used. */ -int 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) +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[nb_codes]; - int i, j; + VLCcode *buf; + int i, j, ret; vlc->bits = nb_bits; - if(flags & INIT_VLC_USE_NEW_STATIC){ - if(vlc->table_size && vlc->table_size == vlc->table_allocated){ + if (flags & INIT_VLC_USE_NEW_STATIC) { + if (vlc->table_size && vlc->table_size == vlc->table_allocated) { return 0; - }else if(vlc->table_size){ - abort(); // fatal error, we are called on a partially initialized table + } else if (vlc->table_size) { + return AVERROR_BUG; } - }else { - vlc->table = NULL; + } else { + vlc->table = NULL; vlc->table_allocated = 0; - vlc->table_size = 0; + vlc->table_size = 0; } -#ifdef DEBUG_VLC - av_log(NULL,AV_LOG_DEBUG,"build table nb_codes=%d\n", nb_codes); -#endif + ff_dlog(NULL, "build table nb_codes=%d\n", nb_codes); + + buf = av_malloc((nb_codes + 1) * sizeof(VLCcode)); + if (!buf) + return AVERROR(ENOMEM); assert(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++;\ +#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 @@ -319,18 +316,22 @@ int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes, COPY(buf[j].bits && buf[j].bits <= nb_bits); nb_codes = j; - if (build_table(vlc, nb_bits, nb_codes, buf, flags) < 0) { + ret = build_table(vlc, nb_bits, nb_codes, buf, flags); + + av_free(buf); + if (ret < 0) { av_freep(&vlc->table); - return -1; + return ret; } - if((flags & INIT_VLC_USE_NEW_STATIC) && vlc->table_size != vlc->table_allocated) - av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", vlc->table_size, vlc->table_allocated); + if ((flags & INIT_VLC_USE_NEW_STATIC) && + vlc->table_size != vlc->table_allocated) + av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", + vlc->table_size, vlc->table_allocated); return 0; } -void free_vlc(VLC *vlc) +void ff_free_vlc(VLC *vlc) { av_freep(&vlc->table); } -