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libavformat/flvdec.c

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00001 /*
00002  * FLV demuxer
00003  * Copyright (c) 2003 The FFmpeg Project
00004  *
00005  * This demuxer will generate a 1 byte extradata for VP6F content.
00006  * It is composed of:
00007  *  - upper 4bits: difference between encoded width and visible width
00008  *  - lower 4bits: difference between encoded height and visible height
00009  *
00010  * This file is part of FFmpeg.
00011  *
00012  * FFmpeg is free software; you can redistribute it and/or
00013  * modify it under the terms of the GNU Lesser General Public
00014  * License as published by the Free Software Foundation; either
00015  * version 2.1 of the License, or (at your option) any later version.
00016  *
00017  * FFmpeg is distributed in the hope that it will be useful,
00018  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00019  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00020  * Lesser General Public License for more details.
00021  *
00022  * You should have received a copy of the GNU Lesser General Public
00023  * License along with FFmpeg; if not, write to the Free Software
00024  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00025  */
00026 
00027 #include "libavutil/avstring.h"
00028 #include "libavutil/dict.h"
00029 #include "libavcodec/bytestream.h"
00030 #include "libavcodec/mpeg4audio.h"
00031 #include "avformat.h"
00032 #include "avio_internal.h"
00033 #include "flv.h"
00034 
00035 typedef struct {
00036     int wrong_dts; 
00037 } FLVContext;
00038 
00039 static int flv_probe(AVProbeData *p)
00040 {
00041     const uint8_t *d;
00042 
00043     d = p->buf;
00044     if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0 && AV_RB32(d+5)>8) {
00045         return AVPROBE_SCORE_MAX;
00046     }
00047     return 0;
00048 }
00049 
00050 static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, int flv_codecid) {
00051     AVCodecContext *acodec = astream->codec;
00052     switch(flv_codecid) {
00053         //no distinction between S16 and S8 PCM codec flags
00054         case FLV_CODECID_PCM:
00055             acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 :
00056 #if HAVE_BIGENDIAN
00057                                 CODEC_ID_PCM_S16BE;
00058 #else
00059                                 CODEC_ID_PCM_S16LE;
00060 #endif
00061             break;
00062         case FLV_CODECID_PCM_LE:
00063             acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 : CODEC_ID_PCM_S16LE; break;
00064         case FLV_CODECID_AAC  : acodec->codec_id = CODEC_ID_AAC;                                    break;
00065         case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF;                              break;
00066         case FLV_CODECID_SPEEX:
00067             acodec->codec_id = CODEC_ID_SPEEX;
00068             acodec->sample_rate = 16000;
00069             break;
00070         case FLV_CODECID_MP3  : acodec->codec_id = CODEC_ID_MP3      ; astream->need_parsing = AVSTREAM_PARSE_FULL; break;
00071         case FLV_CODECID_NELLYMOSER_8KHZ_MONO:
00072             acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate
00073             acodec->codec_id = CODEC_ID_NELLYMOSER;
00074             break;
00075         case FLV_CODECID_NELLYMOSER_16KHZ_MONO:
00076             acodec->sample_rate = 16000;
00077             acodec->codec_id = CODEC_ID_NELLYMOSER;
00078             break;
00079         case FLV_CODECID_NELLYMOSER:
00080             acodec->codec_id = CODEC_ID_NELLYMOSER;
00081             break;
00082         default:
00083             av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
00084             acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET;
00085     }
00086 }
00087 
00088 static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) {
00089     AVCodecContext *vcodec = vstream->codec;
00090     switch(flv_codecid) {
00091         case FLV_CODECID_H263  : vcodec->codec_id = CODEC_ID_FLV1   ; break;
00092         case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break;
00093         case FLV_CODECID_SCREEN2: vcodec->codec_id = CODEC_ID_FLASHSV2; break;
00094         case FLV_CODECID_VP6   : vcodec->codec_id = CODEC_ID_VP6F   ;
00095         case FLV_CODECID_VP6A  :
00096             if(flv_codecid == FLV_CODECID_VP6A)
00097                 vcodec->codec_id = CODEC_ID_VP6A;
00098             if(vcodec->extradata_size != 1) {
00099                 vcodec->extradata_size = 1;
00100                 vcodec->extradata = av_malloc(1);
00101             }
00102             vcodec->extradata[0] = avio_r8(s->pb);
00103             return 1; // 1 byte body size adjustment for flv_read_packet()
00104         case FLV_CODECID_H264:
00105             vcodec->codec_id = CODEC_ID_H264;
00106             return 3; // not 4, reading packet type will consume one byte
00107         default:
00108             av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid);
00109             vcodec->codec_tag = flv_codecid;
00110     }
00111 
00112     return 0;
00113 }
00114 
00115 static int amf_get_string(AVIOContext *ioc, char *buffer, int buffsize) {
00116     int length = avio_rb16(ioc);
00117     if(length >= buffsize) {
00118         avio_skip(ioc, length);
00119         return -1;
00120     }
00121 
00122     avio_read(ioc, buffer, length);
00123 
00124     buffer[length] = '\0';
00125 
00126     return length;
00127 }
00128 
00129 static int parse_keyframes_index(AVFormatContext *s, AVIOContext *ioc, AVStream *vstream, int64_t max_pos) {
00130     unsigned int timeslen = 0, fileposlen = 0, i;
00131     char str_val[256];
00132     int64_t *times = NULL;
00133     int64_t *filepositions = NULL;
00134     int ret = AVERROR(ENOSYS);
00135     int64_t initial_pos = avio_tell(ioc);
00136 
00137     while (avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
00138         int64_t** current_array;
00139         unsigned int arraylen;
00140 
00141         // Expect array object in context
00142         if (avio_r8(ioc) != AMF_DATA_TYPE_ARRAY)
00143             break;
00144 
00145         arraylen = avio_rb32(ioc);
00146         if(arraylen>>28)
00147             break;
00148 
00149         if       (!strcmp(KEYFRAMES_TIMESTAMP_TAG , str_val) && !times){
00150             current_array= &times;
00151             timeslen= arraylen;
00152         }else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) && !filepositions){
00153             current_array= &filepositions;
00154             fileposlen= arraylen;
00155         }else // unexpected metatag inside keyframes, will not use such metadata for indexing
00156             break;
00157 
00158         if (!(*current_array = av_mallocz(sizeof(**current_array) * arraylen))) {
00159             ret = AVERROR(ENOMEM);
00160             goto finish;
00161         }
00162 
00163         for (i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
00164             if (avio_r8(ioc) != AMF_DATA_TYPE_NUMBER)
00165                 goto finish;
00166             current_array[0][i] = av_int2dbl(avio_rb64(ioc));
00167         }
00168         if (times && filepositions) {
00169             // All done, exiting at a position allowing amf_parse_object
00170             // to finish parsing the object
00171             ret = 0;
00172             break;
00173         }
00174     }
00175 
00176     if (!ret && timeslen == fileposlen) {
00177          for (i = 0; i < fileposlen; i++)
00178              av_add_index_entry(vstream, filepositions[i], times[i]*1000, 0, 0, AVINDEX_KEYFRAME);
00179     } else
00180         av_log(s, AV_LOG_WARNING, "Invalid keyframes object, skipping.\n");
00181 
00182 finish:
00183     av_freep(&times);
00184     av_freep(&filepositions);
00185     avio_seek(ioc, initial_pos, SEEK_SET);
00186     return ret;
00187 }
00188 
00189 static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) {
00190     AVCodecContext *acodec, *vcodec;
00191     AVIOContext *ioc;
00192     AMFDataType amf_type;
00193     char str_val[256];
00194     double num_val;
00195 
00196     num_val = 0;
00197     ioc = s->pb;
00198 
00199     amf_type = avio_r8(ioc);
00200 
00201     switch(amf_type) {
00202         case AMF_DATA_TYPE_NUMBER:
00203             num_val = av_int2dbl(avio_rb64(ioc)); break;
00204         case AMF_DATA_TYPE_BOOL:
00205             num_val = avio_r8(ioc); break;
00206         case AMF_DATA_TYPE_STRING:
00207             if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
00208                 return -1;
00209             break;
00210         case AMF_DATA_TYPE_OBJECT: {
00211             unsigned int keylen;
00212 
00213             if (vstream && ioc->seekable && key && !strcmp(KEYFRAMES_TAG, key) && depth == 1)
00214                 if (parse_keyframes_index(s, ioc, vstream, max_pos) < 0)
00215                     av_log(s, AV_LOG_ERROR, "Keyframe index parsing failed\n");
00216 
00217             while(avio_tell(ioc) < max_pos - 2 && (keylen = avio_rb16(ioc))) {
00218                 avio_skip(ioc, keylen); //skip key string
00219                 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
00220                     return -1; //if we couldn't skip, bomb out.
00221             }
00222             if(avio_r8(ioc) != AMF_END_OF_OBJECT)
00223                 return -1;
00224         }
00225             break;
00226         case AMF_DATA_TYPE_NULL:
00227         case AMF_DATA_TYPE_UNDEFINED:
00228         case AMF_DATA_TYPE_UNSUPPORTED:
00229             break; //these take up no additional space
00230         case AMF_DATA_TYPE_MIXEDARRAY:
00231             avio_skip(ioc, 4); //skip 32-bit max array index
00232             while(avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
00233                 //this is the only case in which we would want a nested parse to not skip over the object
00234                 if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
00235                     return -1;
00236             }
00237             if(avio_r8(ioc) != AMF_END_OF_OBJECT)
00238                 return -1;
00239             break;
00240         case AMF_DATA_TYPE_ARRAY: {
00241             unsigned int arraylen, i;
00242 
00243             arraylen = avio_rb32(ioc);
00244             for(i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
00245                 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
00246                     return -1; //if we couldn't skip, bomb out.
00247             }
00248         }
00249             break;
00250         case AMF_DATA_TYPE_DATE:
00251             avio_skip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
00252             break;
00253         default: //unsupported type, we couldn't skip
00254             return -1;
00255     }
00256 
00257     if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
00258         acodec = astream ? astream->codec : NULL;
00259         vcodec = vstream ? vstream->codec : NULL;
00260 
00261         if(amf_type == AMF_DATA_TYPE_BOOL) {
00262             av_strlcpy(str_val, num_val > 0 ? "true" : "false", sizeof(str_val));
00263             av_dict_set(&s->metadata, key, str_val, 0);
00264         } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
00265             snprintf(str_val, sizeof(str_val), "%.f", num_val);
00266             av_dict_set(&s->metadata, key, str_val, 0);
00267             if(!strcmp(key, "duration")) s->duration = num_val * AV_TIME_BASE;
00268             else if(!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0))
00269                 vcodec->bit_rate = num_val * 1024.0;
00270             else if(!strcmp(key, "audiodatarate") && acodec && 0 <= (int)(num_val * 1024.0))
00271                 acodec->bit_rate = num_val * 1024.0;
00272         } else if(amf_type == AMF_DATA_TYPE_OBJECT){
00273             if(s->nb_streams==1 && ((!acodec && !strcmp(key, "audiocodecid")) || (!vcodec && !strcmp(key, "videocodecid")))){
00274                 s->ctx_flags &= ~AVFMTCTX_NOHEADER; //If there is either audio/video missing, codecid will be an empty object
00275             }
00276         } else if (amf_type == AMF_DATA_TYPE_STRING)
00277             av_dict_set(&s->metadata, key, str_val, 0);
00278     }
00279 
00280     return 0;
00281 }
00282 
00283 static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
00284     AMFDataType type;
00285     AVStream *stream, *astream, *vstream;
00286     AVIOContext *ioc;
00287     int i;
00288     char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
00289 
00290     astream = NULL;
00291     vstream = NULL;
00292     ioc = s->pb;
00293 
00294     //first object needs to be "onMetaData" string
00295     type = avio_r8(ioc);
00296     if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
00297         return -1;
00298 
00299     //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
00300     for(i = 0; i < s->nb_streams; i++) {
00301         stream = s->streams[i];
00302         if     (stream->codec->codec_type == AVMEDIA_TYPE_AUDIO) astream = stream;
00303         else if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) vstream = stream;
00304     }
00305 
00306     //parse the second object (we want a mixed array)
00307     if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
00308         return -1;
00309 
00310     return 0;
00311 }
00312 
00313 static AVStream *create_stream(AVFormatContext *s, int is_audio){
00314     AVStream *st = av_new_stream(s, is_audio);
00315     if (!st)
00316         return NULL;
00317     st->codec->codec_type = is_audio ? AVMEDIA_TYPE_AUDIO : AVMEDIA_TYPE_VIDEO;
00318     av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
00319     return st;
00320 }
00321 
00322 static int flv_read_header(AVFormatContext *s,
00323                            AVFormatParameters *ap)
00324 {
00325     int offset, flags;
00326 
00327     avio_skip(s->pb, 4);
00328     flags = avio_r8(s->pb);
00329     /* old flvtool cleared this field */
00330     /* FIXME: better fix needed */
00331     if (!flags) {
00332         flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
00333         av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
00334     }
00335 
00336     if((flags & (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
00337              != (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
00338         s->ctx_flags |= AVFMTCTX_NOHEADER;
00339 
00340     if(flags & FLV_HEADER_FLAG_HASVIDEO){
00341         if(!create_stream(s, 0))
00342             return AVERROR(ENOMEM);
00343     }
00344     if(flags & FLV_HEADER_FLAG_HASAUDIO){
00345         if(!create_stream(s, 1))
00346             return AVERROR(ENOMEM);
00347     }
00348 
00349     offset = avio_rb32(s->pb);
00350     avio_seek(s->pb, offset, SEEK_SET);
00351     avio_skip(s->pb, 4);
00352 
00353     s->start_time = 0;
00354 
00355     return 0;
00356 }
00357 
00358 static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
00359 {
00360     av_free(st->codec->extradata);
00361     st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
00362     if (!st->codec->extradata)
00363         return AVERROR(ENOMEM);
00364     st->codec->extradata_size = size;
00365     avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
00366     return 0;
00367 }
00368 
00369 static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
00370 {
00371     FLVContext *flv = s->priv_data;
00372     int ret, i, type, size, flags, is_audio;
00373     int64_t next, pos;
00374     int64_t dts, pts = AV_NOPTS_VALUE;
00375     AVStream *st = NULL;
00376 
00377  for(;;avio_skip(s->pb, 4)){ /* pkt size is repeated at end. skip it */
00378     pos = avio_tell(s->pb);
00379     type = avio_r8(s->pb);
00380     size = avio_rb24(s->pb);
00381     dts = avio_rb24(s->pb);
00382     dts |= avio_r8(s->pb) << 24;
00383     av_dlog(s, "type:%d, size:%d, dts:%"PRId64"\n", type, size, dts);
00384     if (url_feof(s->pb))
00385         return AVERROR_EOF;
00386     avio_skip(s->pb, 3); /* stream id, always 0 */
00387     flags = 0;
00388 
00389     if(size == 0)
00390         continue;
00391 
00392     next= size + avio_tell(s->pb);
00393 
00394     if (type == FLV_TAG_TYPE_AUDIO) {
00395         is_audio=1;
00396         flags = avio_r8(s->pb);
00397         size--;
00398     } else if (type == FLV_TAG_TYPE_VIDEO) {
00399         is_audio=0;
00400         flags = avio_r8(s->pb);
00401         size--;
00402         if ((flags & 0xf0) == 0x50) /* video info / command frame */
00403             goto skip;
00404     } else {
00405         if (type == FLV_TAG_TYPE_META && size > 13+1+4)
00406             flv_read_metabody(s, next);
00407         else /* skip packet */
00408             av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
00409     skip:
00410         avio_seek(s->pb, next, SEEK_SET);
00411         continue;
00412     }
00413 
00414     /* skip empty data packets */
00415     if (!size)
00416         continue;
00417 
00418     /* now find stream */
00419     for(i=0;i<s->nb_streams;i++) {
00420         st = s->streams[i];
00421         if (st->id == is_audio)
00422             break;
00423     }
00424     if(i == s->nb_streams){
00425         av_log(s, AV_LOG_ERROR, "invalid stream\n");
00426         st= create_stream(s, is_audio);
00427         s->ctx_flags &= ~AVFMTCTX_NOHEADER;
00428     }
00429     av_dlog(s, "%d %X %d \n", is_audio, flags, st->discard);
00430     if(  (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY ||         is_audio))
00431        ||(st->discard >= AVDISCARD_BIDIR  &&  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio))
00432        || st->discard >= AVDISCARD_ALL
00433        ){
00434         avio_seek(s->pb, next, SEEK_SET);
00435         continue;
00436     }
00437     if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
00438         av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME);
00439     break;
00440  }
00441 
00442     // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
00443     if(s->pb->seekable && (!s->duration || s->duration==AV_NOPTS_VALUE)){
00444         int size;
00445         const int64_t pos= avio_tell(s->pb);
00446         const int64_t fsize= avio_size(s->pb);
00447         avio_seek(s->pb, fsize-4, SEEK_SET);
00448         size= avio_rb32(s->pb);
00449         avio_seek(s->pb, fsize-3-size, SEEK_SET);
00450         if(size == avio_rb24(s->pb) + 11){
00451             uint32_t ts = avio_rb24(s->pb);
00452             ts |= avio_r8(s->pb) << 24;
00453             s->duration = ts * (int64_t)AV_TIME_BASE / 1000;
00454         }
00455         avio_seek(s->pb, pos, SEEK_SET);
00456     }
00457 
00458     if(is_audio){
00459         if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) {
00460             st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
00461             st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
00462             st->codec->bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
00463         }
00464         if(!st->codec->codec_id){
00465             flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK);
00466         }
00467     }else{
00468         size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
00469     }
00470 
00471     if (st->codec->codec_id == CODEC_ID_AAC ||
00472         st->codec->codec_id == CODEC_ID_H264) {
00473         int type = avio_r8(s->pb);
00474         size--;
00475         if (st->codec->codec_id == CODEC_ID_H264) {
00476             int32_t cts = (avio_rb24(s->pb)+0xff800000)^0xff800000; // sign extension
00477             pts = dts + cts;
00478             if (cts < 0) { // dts are wrong
00479                 flv->wrong_dts = 1;
00480                 av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n");
00481             }
00482             if (flv->wrong_dts)
00483                 dts = AV_NOPTS_VALUE;
00484         }
00485         if (type == 0) {
00486             if ((ret = flv_get_extradata(s, st, size)) < 0)
00487                 return ret;
00488             if (st->codec->codec_id == CODEC_ID_AAC) {
00489                 MPEG4AudioConfig cfg;
00490                 ff_mpeg4audio_get_config(&cfg, st->codec->extradata,
00491                                          st->codec->extradata_size);
00492                 st->codec->channels = cfg.channels;
00493                 if (cfg.ext_sample_rate)
00494                     st->codec->sample_rate = cfg.ext_sample_rate;
00495                 else
00496                     st->codec->sample_rate = cfg.sample_rate;
00497                 av_dlog(s, "mp4a config channels %d sample rate %d\n",
00498                         st->codec->channels, st->codec->sample_rate);
00499             }
00500 
00501             ret = AVERROR(EAGAIN);
00502             goto leave;
00503         }
00504     }
00505 
00506     /* skip empty data packets */
00507     if (!size) {
00508         ret = AVERROR(EAGAIN);
00509         goto leave;
00510     }
00511 
00512     ret= av_get_packet(s->pb, pkt, size);
00513     if (ret < 0) {
00514         return AVERROR(EIO);
00515     }
00516     /* note: we need to modify the packet size here to handle the last
00517        packet */
00518     pkt->size = ret;
00519     pkt->dts = dts;
00520     pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts;
00521     pkt->stream_index = st->index;
00522 
00523     if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY))
00524         pkt->flags |= AV_PKT_FLAG_KEY;
00525 
00526 leave:
00527     avio_skip(s->pb, 4);
00528     return ret;
00529 }
00530 
00531 static int flv_read_seek(AVFormatContext *s, int stream_index,
00532     int64_t ts, int flags)
00533 {
00534     return avio_seek_time(s->pb, stream_index, ts, flags);
00535 }
00536 
00537 #if 0 /* don't know enough to implement this */
00538 static int flv_read_seek2(AVFormatContext *s, int stream_index,
00539     int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
00540 {
00541     int ret = AVERROR(ENOSYS);
00542 
00543     if (ts - min_ts > (uint64_t)(max_ts - ts)) flags |= AVSEEK_FLAG_BACKWARD;
00544 
00545     if (!s->pb->seekable) {
00546         if (stream_index < 0) {
00547             stream_index = av_find_default_stream_index(s);
00548             if (stream_index < 0)
00549                 return -1;
00550 
00551             /* timestamp for default must be expressed in AV_TIME_BASE units */
00552             ts = av_rescale_rnd(ts, 1000, AV_TIME_BASE,
00553                 flags & AVSEEK_FLAG_BACKWARD ? AV_ROUND_DOWN : AV_ROUND_UP);
00554         }
00555         ret = avio_seek_time(s->pb, stream_index, ts, flags);
00556     }
00557 
00558     if (ret == AVERROR(ENOSYS))
00559         ret = av_seek_frame(s, stream_index, ts, flags);
00560     return ret;
00561 }
00562 #endif
00563 
00564 AVInputFormat ff_flv_demuxer = {
00565     "flv",
00566     NULL_IF_CONFIG_SMALL("FLV format"),
00567     sizeof(FLVContext),
00568     flv_probe,
00569     flv_read_header,
00570     flv_read_packet,
00571     .read_seek = flv_read_seek,
00572 #if 0
00573     .read_seek2 = flv_read_seek2,
00574 #endif
00575     .extensions = "flv",
00576     .value = CODEC_ID_FLV1,
00577 };

Generated on Fri Feb 22 2013 07:24:26 for FFmpeg by  doxygen 1.7.1