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libavcodec/parser.c

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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 Libav.
00007  *
00008  * Libav 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  * Libav 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 Libav; 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     if (parser->priv_data_size) {
00062         s->priv_data = av_mallocz(parser->priv_data_size);
00063         if (!s->priv_data) {
00064             av_free(s);
00065             return NULL;
00066         }
00067     }
00068     if (parser->parser_init) {
00069         ret = parser->parser_init(s);
00070         if (ret != 0) {
00071             av_free(s->priv_data);
00072             av_free(s);
00073             return NULL;
00074         }
00075     }
00076     s->fetch_timestamp=1;
00077     s->pict_type = AV_PICTURE_TYPE_I;
00078     s->key_frame = -1;
00079     s->convergence_duration = 0;
00080     s->dts_sync_point       = INT_MIN;
00081     s->dts_ref_dts_delta    = INT_MIN;
00082     s->pts_dts_delta        = INT_MIN;
00083     return s;
00084 }
00085 
00086 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove){
00087     int i;
00088 
00089     s->dts= s->pts= AV_NOPTS_VALUE;
00090     s->pos= -1;
00091     s->offset= 0;
00092     for(i = 0; i < AV_PARSER_PTS_NB; i++) {
00093         if (   s->cur_offset + off >= s->cur_frame_offset[i]
00094             && (s->frame_offset < s->cur_frame_offset[i] ||
00095               (!s->frame_offset && !s->next_frame_offset)) // first field/frame
00096             //check is disabled  because mpeg-ts doesnt send complete PES packets
00097             && /*s->next_frame_offset + off <*/  s->cur_frame_end[i]){
00098             s->dts= s->cur_frame_dts[i];
00099             s->pts= s->cur_frame_pts[i];
00100             s->pos= s->cur_frame_pos[i];
00101             s->offset = s->next_frame_offset - s->cur_frame_offset[i];
00102             if(remove)
00103                 s->cur_frame_offset[i]= INT64_MAX;
00104             if(s->cur_offset + off < s->cur_frame_end[i])
00105                 break;
00106         }
00107     }
00108 }
00109 
00110 int av_parser_parse2(AVCodecParserContext *s,
00111                      AVCodecContext *avctx,
00112                      uint8_t **poutbuf, int *poutbuf_size,
00113                      const uint8_t *buf, int buf_size,
00114                      int64_t pts, int64_t dts,
00115                      int64_t pos)
00116 {
00117     int index, i;
00118     uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
00119 
00120     if(!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
00121         s->next_frame_offset =
00122         s->cur_offset        = pos;
00123         s->flags |= PARSER_FLAG_FETCHED_OFFSET;
00124     }
00125 
00126     if (buf_size == 0) {
00127         /* padding is always necessary even if EOF, so we add it here */
00128         memset(dummy_buf, 0, sizeof(dummy_buf));
00129         buf = dummy_buf;
00130     } else if (s->cur_offset + buf_size !=
00131                s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
00132         /* add a new packet descriptor */
00133             i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
00134             s->cur_frame_start_index = i;
00135             s->cur_frame_offset[i] = s->cur_offset;
00136             s->cur_frame_end[i] = s->cur_offset + buf_size;
00137             s->cur_frame_pts[i] = pts;
00138             s->cur_frame_dts[i] = dts;
00139             s->cur_frame_pos[i] = pos;
00140     }
00141 
00142     if (s->fetch_timestamp){
00143         s->fetch_timestamp=0;
00144         s->last_pts = s->pts;
00145         s->last_dts = s->dts;
00146         s->last_pos = s->pos;
00147         ff_fetch_timestamp(s, 0, 0);
00148     }
00149 
00150     /* WARNING: the returned index can be negative */
00151     index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size);
00152 //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);
00153     /* update the file pointer */
00154     if (*poutbuf_size) {
00155         /* fill the data for the current frame */
00156         s->frame_offset = s->next_frame_offset;
00157 
00158         /* offset of the next frame */
00159         s->next_frame_offset = s->cur_offset + index;
00160         s->fetch_timestamp=1;
00161     }
00162     if (index < 0)
00163         index = 0;
00164     s->cur_offset += index;
00165     return index;
00166 }
00167 
00173 int av_parser_change(AVCodecParserContext *s,
00174                      AVCodecContext *avctx,
00175                      uint8_t **poutbuf, int *poutbuf_size,
00176                      const uint8_t *buf, int buf_size, int keyframe){
00177 
00178     if(s && s->parser->split){
00179         if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){
00180             int i= s->parser->split(avctx, buf, buf_size);
00181             buf += i;
00182             buf_size -= i;
00183         }
00184     }
00185 
00186     /* cast to avoid warning about discarding qualifiers */
00187     *poutbuf= (uint8_t *) buf;
00188     *poutbuf_size= buf_size;
00189     if(avctx->extradata){
00190         if(  (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER))
00191             /*||(s->pict_type != AV_PICTURE_TYPE_I && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/
00192             /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
00193             int size= buf_size + avctx->extradata_size;
00194             *poutbuf_size= size;
00195             *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
00196 
00197             memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
00198             memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
00199             return 1;
00200         }
00201     }
00202 
00203     return 0;
00204 }
00205 
00206 void av_parser_close(AVCodecParserContext *s)
00207 {
00208     if(s){
00209         if (s->parser->parser_close)
00210             s->parser->parser_close(s);
00211         av_free(s->priv_data);
00212         av_free(s);
00213     }
00214 }
00215 
00216 /*****************************************************/
00217 
00222 int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
00223 {
00224     if(pc->overread){
00225         av_dlog(pc, "overread %d, state:%X next:%d index:%d o_index:%d\n",
00226                 pc->overread, pc->state, next, pc->index, pc->overread_index);
00227         av_dlog(pc, "%X %X %X %X\n", (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
00228     }
00229 
00230     /* Copy overread bytes from last frame into buffer. */
00231     for(; pc->overread>0; pc->overread--){
00232         pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
00233     }
00234 
00235     /* flush remaining if EOF */
00236     if(!*buf_size && next == END_NOT_FOUND){
00237         next= 0;
00238     }
00239 
00240     pc->last_index= pc->index;
00241 
00242     /* copy into buffer end return */
00243     if(next == END_NOT_FOUND){
00244         void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
00245 
00246         if(!new_buffer)
00247             return AVERROR(ENOMEM);
00248         pc->buffer = new_buffer;
00249         memcpy(&pc->buffer[pc->index], *buf, *buf_size);
00250         pc->index += *buf_size;
00251         return -1;
00252     }
00253 
00254     *buf_size=
00255     pc->overread_index= pc->index + next;
00256 
00257     /* append to buffer */
00258     if(pc->index){
00259         void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
00260 
00261         if(!new_buffer)
00262             return AVERROR(ENOMEM);
00263         pc->buffer = new_buffer;
00264         memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
00265         pc->index = 0;
00266         *buf= pc->buffer;
00267     }
00268 
00269     /* store overread bytes */
00270     for(;next < 0; next++){
00271         pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
00272         pc->state64 = (pc->state64<<8) | pc->buffer[pc->last_index + next];
00273         pc->overread++;
00274     }
00275 
00276     if(pc->overread){
00277         av_dlog(pc, "overread %d, state:%X next:%d index:%d o_index:%d\n",
00278                 pc->overread, pc->state, next, pc->index, pc->overread_index);
00279         av_dlog(pc, "%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
00280     }
00281 
00282     return 0;
00283 }
00284 
00285 void ff_parse_close(AVCodecParserContext *s)
00286 {
00287     ParseContext *pc = s->priv_data;
00288 
00289     av_freep(&pc->buffer);
00290 }
00291 
00292 void ff_parse1_close(AVCodecParserContext *s)
00293 {
00294     ParseContext1 *pc1 = s->priv_data;
00295 
00296     av_free(pc1->pc.buffer);
00297     av_free(pc1->enc);
00298 }
00299 
00300 /*************************/
00301 
00302 int ff_mpeg4video_split(AVCodecContext *avctx,
00303                            const uint8_t *buf, int buf_size)
00304 {
00305     int i;
00306     uint32_t state= -1;
00307 
00308     for(i=0; i<buf_size; i++){
00309         state= (state<<8) | buf[i];
00310         if(state == 0x1B3 || state == 0x1B6)
00311             return i-3;
00312     }
00313     return 0;
00314 }
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