Libav
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00001 /* 00002 * Audio and Video frame extraction 00003 * Copyright (c) 2003 Fabrice Bellard 00004 * Copyright (c) 2003 Michael Niedermayer 00005 * 00006 * This file is part of FFmpeg. 00007 * 00008 * FFmpeg is free software; you can redistribute it and/or 00009 * modify it under the terms of the GNU Lesser General Public 00010 * License as published by the Free Software Foundation; either 00011 * version 2.1 of the License, or (at your option) any later version. 00012 * 00013 * FFmpeg is distributed in the hope that it will be useful, 00014 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00016 * Lesser General Public License for more details. 00017 * 00018 * You should have received a copy of the GNU Lesser General Public 00019 * License along with FFmpeg; if not, write to the Free Software 00020 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00021 */ 00022 00023 #include "parser.h" 00024 00025 static AVCodecParser *av_first_parser = NULL; 00026 00027 AVCodecParser* av_parser_next(AVCodecParser *p){ 00028 if(p) return p->next; 00029 else return av_first_parser; 00030 } 00031 00032 void av_register_codec_parser(AVCodecParser *parser) 00033 { 00034 parser->next = av_first_parser; 00035 av_first_parser = parser; 00036 } 00037 00038 AVCodecParserContext *av_parser_init(int codec_id) 00039 { 00040 AVCodecParserContext *s; 00041 AVCodecParser *parser; 00042 int ret; 00043 00044 if(codec_id == CODEC_ID_NONE) 00045 return NULL; 00046 00047 for(parser = av_first_parser; parser != NULL; parser = parser->next) { 00048 if (parser->codec_ids[0] == codec_id || 00049 parser->codec_ids[1] == codec_id || 00050 parser->codec_ids[2] == codec_id || 00051 parser->codec_ids[3] == codec_id || 00052 parser->codec_ids[4] == codec_id) 00053 goto found; 00054 } 00055 return NULL; 00056 found: 00057 s = av_mallocz(sizeof(AVCodecParserContext)); 00058 if (!s) 00059 return NULL; 00060 s->parser = parser; 00061 s->priv_data = av_mallocz(parser->priv_data_size); 00062 if (!s->priv_data) { 00063 av_free(s); 00064 return NULL; 00065 } 00066 if (parser->parser_init) { 00067 ret = parser->parser_init(s); 00068 if (ret != 0) { 00069 av_free(s->priv_data); 00070 av_free(s); 00071 return NULL; 00072 } 00073 } 00074 s->fetch_timestamp=1; 00075 s->pict_type = FF_I_TYPE; 00076 s->key_frame = -1; 00077 s->convergence_duration = AV_NOPTS_VALUE; 00078 s->dts_sync_point = INT_MIN; 00079 s->dts_ref_dts_delta = INT_MIN; 00080 s->pts_dts_delta = INT_MIN; 00081 return s; 00082 } 00083 00084 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove){ 00085 int i; 00086 00087 s->dts= s->pts= AV_NOPTS_VALUE; 00088 s->pos= -1; 00089 s->offset= 0; 00090 for(i = 0; i < AV_PARSER_PTS_NB; i++) { 00091 if ( s->cur_offset + off >= s->cur_frame_offset[i] 00092 && (s->frame_offset < s->cur_frame_offset[i] || 00093 (!s->frame_offset && !s->next_frame_offset)) // first field/frame 00094 //check is disabled because mpeg-ts doesnt send complete PES packets 00095 && /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){ 00096 s->dts= s->cur_frame_dts[i]; 00097 s->pts= s->cur_frame_pts[i]; 00098 s->pos= s->cur_frame_pos[i]; 00099 s->offset = s->next_frame_offset - s->cur_frame_offset[i]; 00100 if(remove) 00101 s->cur_frame_offset[i]= INT64_MAX; 00102 if(s->cur_offset + off < s->cur_frame_end[i]) 00103 break; 00104 } 00105 } 00106 } 00107 00134 int av_parser_parse(AVCodecParserContext *s, 00135 AVCodecContext *avctx, 00136 uint8_t **poutbuf, int *poutbuf_size, 00137 const uint8_t *buf, int buf_size, 00138 int64_t pts, int64_t dts) 00139 { 00140 return av_parser_parse2(s, avctx, poutbuf, poutbuf_size, buf, buf_size, pts, dts, AV_NOPTS_VALUE); 00141 } 00142 00143 int av_parser_parse2(AVCodecParserContext *s, 00144 AVCodecContext *avctx, 00145 uint8_t **poutbuf, int *poutbuf_size, 00146 const uint8_t *buf, int buf_size, 00147 int64_t pts, int64_t dts, 00148 int64_t pos) 00149 { 00150 int index, i; 00151 uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE]; 00152 00153 if (buf_size == 0) { 00154 /* padding is always necessary even if EOF, so we add it here */ 00155 memset(dummy_buf, 0, sizeof(dummy_buf)); 00156 buf = dummy_buf; 00157 } else if (s->cur_offset + buf_size != 00158 s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */ 00159 /* add a new packet descriptor */ 00160 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1); 00161 s->cur_frame_start_index = i; 00162 s->cur_frame_offset[i] = s->cur_offset; 00163 s->cur_frame_end[i] = s->cur_offset + buf_size; 00164 s->cur_frame_pts[i] = pts; 00165 s->cur_frame_dts[i] = dts; 00166 s->cur_frame_pos[i] = pos; 00167 } 00168 00169 if (s->fetch_timestamp){ 00170 s->fetch_timestamp=0; 00171 s->last_pts = s->pts; 00172 s->last_dts = s->dts; 00173 s->last_pos = s->pos; 00174 ff_fetch_timestamp(s, 0, 0); 00175 } 00176 00177 /* WARNING: the returned index can be negative */ 00178 index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size); 00179 //av_log(NULL, AV_LOG_DEBUG, "parser: in:%"PRId64", %"PRId64", out:%"PRId64", %"PRId64", in:%d out:%d id:%d\n", pts, dts, s->last_pts, s->last_dts, buf_size, *poutbuf_size, avctx->codec_id); 00180 /* update the file pointer */ 00181 if (*poutbuf_size) { 00182 /* fill the data for the current frame */ 00183 s->frame_offset = s->next_frame_offset; 00184 00185 /* offset of the next frame */ 00186 s->next_frame_offset = s->cur_offset + index; 00187 s->fetch_timestamp=1; 00188 } 00189 if (index < 0) 00190 index = 0; 00191 s->cur_offset += index; 00192 return index; 00193 } 00194 00200 int av_parser_change(AVCodecParserContext *s, 00201 AVCodecContext *avctx, 00202 uint8_t **poutbuf, int *poutbuf_size, 00203 const uint8_t *buf, int buf_size, int keyframe){ 00204 00205 if(s && s->parser->split){ 00206 if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){ 00207 int i= s->parser->split(avctx, buf, buf_size); 00208 buf += i; 00209 buf_size -= i; 00210 } 00211 } 00212 00213 /* cast to avoid warning about discarding qualifiers */ 00214 *poutbuf= (uint8_t *) buf; 00215 *poutbuf_size= buf_size; 00216 if(avctx->extradata){ 00217 if( (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)) 00218 /*||(s->pict_type != FF_I_TYPE && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/ 00219 /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){ 00220 int size= buf_size + avctx->extradata_size; 00221 *poutbuf_size= size; 00222 *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE); 00223 00224 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size); 00225 memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); 00226 return 1; 00227 } 00228 } 00229 00230 return 0; 00231 } 00232 00233 void av_parser_close(AVCodecParserContext *s) 00234 { 00235 if(s){ 00236 if (s->parser->parser_close) 00237 s->parser->parser_close(s); 00238 av_free(s->priv_data); 00239 av_free(s); 00240 } 00241 } 00242 00243 /*****************************************************/ 00244 00249 int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size) 00250 { 00251 #if 0 00252 if(pc->overread){ 00253 printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index); 00254 printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]); 00255 } 00256 #endif 00257 00258 /* Copy overread bytes from last frame into buffer. */ 00259 for(; pc->overread>0; pc->overread--){ 00260 pc->buffer[pc->index++]= pc->buffer[pc->overread_index++]; 00261 } 00262 00263 /* flush remaining if EOF */ 00264 if(!*buf_size && next == END_NOT_FOUND){ 00265 next= 0; 00266 } 00267 00268 pc->last_index= pc->index; 00269 00270 /* copy into buffer end return */ 00271 if(next == END_NOT_FOUND){ 00272 void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE); 00273 00274 if(!new_buffer) 00275 return AVERROR(ENOMEM); 00276 pc->buffer = new_buffer; 00277 memcpy(&pc->buffer[pc->index], *buf, *buf_size); 00278 pc->index += *buf_size; 00279 return -1; 00280 } 00281 00282 *buf_size= 00283 pc->overread_index= pc->index + next; 00284 00285 /* append to buffer */ 00286 if(pc->index){ 00287 void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE); 00288 00289 if(!new_buffer) 00290 return AVERROR(ENOMEM); 00291 pc->buffer = new_buffer; 00292 memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE ); 00293 pc->index = 0; 00294 *buf= pc->buffer; 00295 } 00296 00297 /* store overread bytes */ 00298 for(;next < 0; next++){ 00299 pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next]; 00300 pc->state64 = (pc->state64<<8) | pc->buffer[pc->last_index + next]; 00301 pc->overread++; 00302 } 00303 00304 #if 0 00305 if(pc->overread){ 00306 printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index); 00307 printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]); 00308 } 00309 #endif 00310 00311 return 0; 00312 } 00313 00314 void ff_parse_close(AVCodecParserContext *s) 00315 { 00316 ParseContext *pc = s->priv_data; 00317 00318 av_freep(&pc->buffer); 00319 } 00320 00321 void ff_parse1_close(AVCodecParserContext *s) 00322 { 00323 ParseContext1 *pc1 = s->priv_data; 00324 00325 av_free(pc1->pc.buffer); 00326 av_free(pc1->enc); 00327 } 00328 00329 /*************************/ 00330 00331 int ff_mpeg4video_split(AVCodecContext *avctx, 00332 const uint8_t *buf, int buf_size) 00333 { 00334 int i; 00335 uint32_t state= -1; 00336 00337 for(i=0; i<buf_size; i++){ 00338 state= (state<<8) | buf[i]; 00339 if(state == 0x1B3 || state == 0x1B6) 00340 return i-3; 00341 } 00342 return 0; 00343 }