libavformat/flvdec.c
Go to the documentation of this file.
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 "libavutil/intfloat.h"
00030 #include "libavutil/mathematics.h"
00031 #include "libavcodec/bytestream.h"
00032 #include "libavcodec/mpeg4audio.h"
00033 #include "avformat.h"
00034 #include "internal.h"
00035 #include "avio_internal.h"
00036 #include "flv.h"
00037 
00038 typedef struct {
00039     int wrong_dts; 
00040     uint8_t *new_extradata[FLV_STREAM_TYPE_NB];
00041     int      new_extradata_size[FLV_STREAM_TYPE_NB];
00042     int      last_sample_rate;
00043     int      last_channels;
00044 } FLVContext;
00045 
00046 static int flv_probe(AVProbeData *p)
00047 {
00048     const uint8_t *d;
00049 
00050     d = p->buf;
00051     if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0 && AV_RB32(d+5)>8) {
00052         return AVPROBE_SCORE_MAX;
00053     }
00054     return 0;
00055 }
00056 
00057 static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, AVCodecContext *acodec, int flv_codecid) {
00058     switch(flv_codecid) {
00059         //no distinction between S16 and S8 PCM codec flags
00060         case FLV_CODECID_PCM:
00061             acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 :
00062 #if HAVE_BIGENDIAN
00063                                 CODEC_ID_PCM_S16BE;
00064 #else
00065                                 CODEC_ID_PCM_S16LE;
00066 #endif
00067             break;
00068         case FLV_CODECID_PCM_LE:
00069             acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 : CODEC_ID_PCM_S16LE; break;
00070         case FLV_CODECID_AAC  : acodec->codec_id = CODEC_ID_AAC;                                    break;
00071         case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF;                              break;
00072         case FLV_CODECID_SPEEX:
00073             acodec->codec_id = CODEC_ID_SPEEX;
00074             acodec->sample_rate = 16000;
00075             break;
00076         case FLV_CODECID_MP3  : acodec->codec_id = CODEC_ID_MP3      ; astream->need_parsing = AVSTREAM_PARSE_FULL; break;
00077         case FLV_CODECID_NELLYMOSER_8KHZ_MONO:
00078             acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate
00079             acodec->codec_id = CODEC_ID_NELLYMOSER;
00080             break;
00081         case FLV_CODECID_NELLYMOSER_16KHZ_MONO:
00082             acodec->sample_rate = 16000;
00083             acodec->codec_id = CODEC_ID_NELLYMOSER;
00084             break;
00085         case FLV_CODECID_NELLYMOSER:
00086             acodec->codec_id = CODEC_ID_NELLYMOSER;
00087             break;
00088         default:
00089             av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
00090             acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET;
00091     }
00092 }
00093 
00094 static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) {
00095     AVCodecContext *vcodec = vstream->codec;
00096     switch(flv_codecid) {
00097         case FLV_CODECID_H263  : vcodec->codec_id = CODEC_ID_FLV1   ; break;
00098         case FLV_CODECID_REALH263: vcodec->codec_id = CODEC_ID_H263 ; break; // Really mean it this time
00099         case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break;
00100         case FLV_CODECID_SCREEN2: vcodec->codec_id = CODEC_ID_FLASHSV2; break;
00101         case FLV_CODECID_VP6   : vcodec->codec_id = CODEC_ID_VP6F   ;
00102         case FLV_CODECID_VP6A  :
00103             if(flv_codecid == FLV_CODECID_VP6A)
00104                 vcodec->codec_id = CODEC_ID_VP6A;
00105             if(vcodec->extradata_size != 1) {
00106                 vcodec->extradata_size = 1;
00107                 vcodec->extradata = av_malloc(1);
00108             }
00109             vcodec->extradata[0] = avio_r8(s->pb);
00110             return 1; // 1 byte body size adjustment for flv_read_packet()
00111         case FLV_CODECID_H264:
00112             vcodec->codec_id = CODEC_ID_H264;
00113             return 3; // not 4, reading packet type will consume one byte
00114         case FLV_CODECID_MPEG4:
00115             vcodec->codec_id = CODEC_ID_MPEG4;
00116             return 3;
00117         default:
00118             av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid);
00119             vcodec->codec_tag = flv_codecid;
00120     }
00121 
00122     return 0;
00123 }
00124 
00125 static int amf_get_string(AVIOContext *ioc, char *buffer, int buffsize) {
00126     int length = avio_rb16(ioc);
00127     if(length >= buffsize) {
00128         avio_skip(ioc, length);
00129         return -1;
00130     }
00131 
00132     avio_read(ioc, buffer, length);
00133 
00134     buffer[length] = '\0';
00135 
00136     return length;
00137 }
00138 
00139 static int parse_keyframes_index(AVFormatContext *s, AVIOContext *ioc, AVStream *vstream, int64_t max_pos) {
00140     unsigned int timeslen = 0, fileposlen = 0, i;
00141     char str_val[256];
00142     int64_t *times = NULL;
00143     int64_t *filepositions = NULL;
00144     int ret = AVERROR(ENOSYS);
00145     int64_t initial_pos = avio_tell(ioc);
00146 
00147     if(vstream->nb_index_entries>0){
00148         av_log(s, AV_LOG_WARNING, "Skiping duplicate index\n");
00149         return 0;
00150     }
00151 
00152     while (avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
00153         int64_t** current_array;
00154         unsigned int arraylen;
00155 
00156         // Expect array object in context
00157         if (avio_r8(ioc) != AMF_DATA_TYPE_ARRAY)
00158             break;
00159 
00160         arraylen = avio_rb32(ioc);
00161         if(arraylen>>28)
00162             break;
00163 
00164         if       (!strcmp(KEYFRAMES_TIMESTAMP_TAG , str_val) && !times){
00165             current_array= &times;
00166             timeslen= arraylen;
00167         }else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) && !filepositions){
00168             current_array= &filepositions;
00169             fileposlen= arraylen;
00170         }else // unexpected metatag inside keyframes, will not use such metadata for indexing
00171             break;
00172 
00173         if (!(*current_array = av_mallocz(sizeof(**current_array) * arraylen))) {
00174             ret = AVERROR(ENOMEM);
00175             goto finish;
00176         }
00177 
00178         for (i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
00179             if (avio_r8(ioc) != AMF_DATA_TYPE_NUMBER)
00180                 goto invalid;
00181             current_array[0][i] = av_int2double(avio_rb64(ioc));
00182         }
00183         if (times && filepositions) {
00184             // All done, exiting at a position allowing amf_parse_object
00185             // to finish parsing the object
00186             ret = 0;
00187             break;
00188         }
00189     }
00190 
00191     if (timeslen == fileposlen && fileposlen>1 && max_pos <= filepositions[0]) {
00192         int64_t dts, size0, size1;
00193         avio_seek(ioc, filepositions[1]-4, SEEK_SET);
00194         size0 = avio_rb32(ioc);
00195                 avio_r8(ioc);
00196         size1 = avio_rb24(ioc);
00197         dts   = avio_rb24(ioc);
00198         dts  |= avio_r8(ioc) << 24;
00199         if (size0 > filepositions[1] || FFABS(dts - times[1]*1000)>5000/*arbitraray threshold to detect invalid index*/)
00200             goto invalid;
00201          for(i = 0; i < timeslen; i++)
00202              av_add_index_entry(vstream, filepositions[i], times[i]*1000, 0, 0, AVINDEX_KEYFRAME);
00203     } else {
00204 invalid:
00205         av_log(s, AV_LOG_WARNING, "Invalid keyframes object, skipping.\n");
00206     }
00207 
00208 finish:
00209     av_freep(&times);
00210     av_freep(&filepositions);
00211     avio_seek(ioc, initial_pos, SEEK_SET);
00212     return ret;
00213 }
00214 
00215 static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) {
00216     AVCodecContext *acodec, *vcodec;
00217     AVIOContext *ioc;
00218     AMFDataType amf_type;
00219     char str_val[256];
00220     double num_val;
00221 
00222     num_val = 0;
00223     ioc = s->pb;
00224 
00225     amf_type = avio_r8(ioc);
00226 
00227     switch(amf_type) {
00228         case AMF_DATA_TYPE_NUMBER:
00229             num_val = av_int2double(avio_rb64(ioc)); break;
00230         case AMF_DATA_TYPE_BOOL:
00231             num_val = avio_r8(ioc); break;
00232         case AMF_DATA_TYPE_STRING:
00233             if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
00234                 return -1;
00235             break;
00236         case AMF_DATA_TYPE_OBJECT: {
00237             unsigned int keylen;
00238 
00239             if ((vstream || astream) && ioc->seekable && key && !strcmp(KEYFRAMES_TAG, key) && depth == 1)
00240                 if (parse_keyframes_index(s, ioc, vstream ? vstream : astream,
00241                                           max_pos) < 0)
00242                     av_log(s, AV_LOG_ERROR, "Keyframe index parsing failed\n");
00243 
00244             while(avio_tell(ioc) < max_pos - 2 && (keylen = avio_rb16(ioc))) {
00245                 avio_skip(ioc, keylen); //skip key string
00246                 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
00247                     return -1; //if we couldn't skip, bomb out.
00248             }
00249             if(avio_r8(ioc) != AMF_END_OF_OBJECT)
00250                 return -1;
00251         }
00252             break;
00253         case AMF_DATA_TYPE_NULL:
00254         case AMF_DATA_TYPE_UNDEFINED:
00255         case AMF_DATA_TYPE_UNSUPPORTED:
00256             break; //these take up no additional space
00257         case AMF_DATA_TYPE_MIXEDARRAY:
00258             avio_skip(ioc, 4); //skip 32-bit max array index
00259             while(avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
00260                 //this is the only case in which we would want a nested parse to not skip over the object
00261                 if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
00262                     return -1;
00263             }
00264             if(avio_r8(ioc) != AMF_END_OF_OBJECT)
00265                 return -1;
00266             break;
00267         case AMF_DATA_TYPE_ARRAY: {
00268             unsigned int arraylen, i;
00269 
00270             arraylen = avio_rb32(ioc);
00271             for(i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
00272                 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
00273                     return -1; //if we couldn't skip, bomb out.
00274             }
00275         }
00276             break;
00277         case AMF_DATA_TYPE_DATE:
00278             avio_skip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
00279             break;
00280         default: //unsupported type, we couldn't skip
00281             return -1;
00282     }
00283 
00284     if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
00285         acodec = astream ? astream->codec : NULL;
00286         vcodec = vstream ? vstream->codec : NULL;
00287 
00288         if (amf_type == AMF_DATA_TYPE_NUMBER) {
00289             if (!strcmp(key, "duration"))
00290                 s->duration = num_val * AV_TIME_BASE;
00291             else if (!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0))
00292                 vcodec->bit_rate = num_val * 1024.0;
00293             else if (!strcmp(key, "audiodatarate") && acodec && 0 <= (int)(num_val * 1024.0))
00294                 acodec->bit_rate = num_val * 1024.0;
00295         }
00296 
00297         if (amf_type == AMF_DATA_TYPE_OBJECT && s->nb_streams == 1 &&
00298            ((!acodec && !strcmp(key, "audiocodecid")) ||
00299             (!vcodec && !strcmp(key, "videocodecid"))))
00300                 s->ctx_flags &= ~AVFMTCTX_NOHEADER; //If there is either audio/video missing, codecid will be an empty object
00301 
00302         if (!strcmp(key, "duration")        ||
00303             !strcmp(key, "filesize")        ||
00304             !strcmp(key, "width")           ||
00305             !strcmp(key, "height")          ||
00306             !strcmp(key, "videodatarate")   ||
00307             !strcmp(key, "framerate")       ||
00308             !strcmp(key, "videocodecid")    ||
00309             !strcmp(key, "audiodatarate")   ||
00310             !strcmp(key, "audiosamplerate") ||
00311             !strcmp(key, "audiosamplesize") ||
00312             !strcmp(key, "stereo")          ||
00313             !strcmp(key, "audiocodecid"))
00314             return 0;
00315 
00316         if(amf_type == AMF_DATA_TYPE_BOOL) {
00317             av_strlcpy(str_val, num_val > 0 ? "true" : "false", sizeof(str_val));
00318             av_dict_set(&s->metadata, key, str_val, 0);
00319         } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
00320             snprintf(str_val, sizeof(str_val), "%.f", num_val);
00321             av_dict_set(&s->metadata, key, str_val, 0);
00322         } else if (amf_type == AMF_DATA_TYPE_STRING)
00323             av_dict_set(&s->metadata, key, str_val, 0);
00324     }
00325 
00326     return 0;
00327 }
00328 
00329 static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
00330     AMFDataType type;
00331     AVStream *stream, *astream, *vstream, *dstream;
00332     AVIOContext *ioc;
00333     int i;
00334     char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
00335 
00336     vstream = astream = dstream = NULL;
00337     ioc = s->pb;
00338 
00339     //first object needs to be "onMetaData" string
00340     type = avio_r8(ioc);
00341     if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
00342         return -1;
00343 
00344     //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
00345     for(i = 0; i < s->nb_streams; i++) {
00346         stream = s->streams[i];
00347         if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) vstream = stream;
00348         else if(stream->codec->codec_type == AVMEDIA_TYPE_AUDIO) astream = stream;
00349         else if(stream->codec->codec_type == AVMEDIA_TYPE_DATA) dstream = stream;
00350     }
00351 
00352     //parse the second object (we want a mixed array)
00353     if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
00354         return -1;
00355 
00356     return 0;
00357 }
00358 
00359 static AVStream *create_stream(AVFormatContext *s, int stream_type){
00360     AVStream *st = avformat_new_stream(s, NULL);
00361     if (!st)
00362         return NULL;
00363     st->id = stream_type;
00364     switch(stream_type) {
00365         case FLV_STREAM_TYPE_VIDEO:    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;    break;
00366         case FLV_STREAM_TYPE_AUDIO:    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;    break;
00367         case FLV_STREAM_TYPE_DATA:
00368             st->codec->codec_type = AVMEDIA_TYPE_DATA;
00369             st->codec->codec_id = CODEC_ID_NONE; // Going to rely on copy for now
00370             av_log(s, AV_LOG_DEBUG, "Data stream created\n");
00371     }
00372     if(s->nb_streams>=3 ||(   s->nb_streams==2
00373                            && s->streams[0]->codec->codec_type != AVMEDIA_TYPE_DATA
00374                            && s->streams[1]->codec->codec_type != AVMEDIA_TYPE_DATA))
00375         s->ctx_flags &= ~AVFMTCTX_NOHEADER;
00376 
00377     avpriv_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
00378     return st;
00379 }
00380 
00381 static int flv_read_header(AVFormatContext *s,
00382                            AVFormatParameters *ap)
00383 {
00384     int offset, flags;
00385 
00386     avio_skip(s->pb, 4);
00387     flags = avio_r8(s->pb);
00388     /* old flvtool cleared this field */
00389     /* FIXME: better fix needed */
00390     if (!flags) {
00391         flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
00392         av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
00393     }
00394         s->ctx_flags |= AVFMTCTX_NOHEADER;
00395 
00396     if(flags & FLV_HEADER_FLAG_HASVIDEO){
00397         if(!create_stream(s, FLV_STREAM_TYPE_VIDEO))
00398             return AVERROR(ENOMEM);
00399     }
00400     if(flags & FLV_HEADER_FLAG_HASAUDIO){
00401         if(!create_stream(s, FLV_STREAM_TYPE_AUDIO))
00402             return AVERROR(ENOMEM);
00403     }
00404     // Flag doesn't indicate whether or not there is script-data present. Must
00405     // create that stream if it's encountered.
00406 
00407     offset = avio_rb32(s->pb);
00408     avio_seek(s->pb, offset, SEEK_SET);
00409     avio_skip(s->pb, 4);
00410 
00411     s->start_time = 0;
00412 
00413     return 0;
00414 }
00415 
00416 static int flv_read_close(AVFormatContext *s)
00417 {
00418     int i;
00419     FLVContext *flv = s->priv_data;
00420     for(i=0; i<FLV_STREAM_TYPE_NB; i++)
00421         av_freep(&flv->new_extradata[i]);
00422     return 0;
00423 }
00424 
00425 static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
00426 {
00427     av_free(st->codec->extradata);
00428     st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
00429     if (!st->codec->extradata)
00430         return AVERROR(ENOMEM);
00431     st->codec->extradata_size = size;
00432     avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
00433     return 0;
00434 }
00435 
00436 static int flv_queue_extradata(FLVContext *flv, AVIOContext *pb, int stream,
00437                                int size)
00438 {
00439     av_free(flv->new_extradata[stream]);
00440     flv->new_extradata[stream] = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
00441     if (!flv->new_extradata[stream])
00442         return AVERROR(ENOMEM);
00443     flv->new_extradata_size[stream] = size;
00444     avio_read(pb, flv->new_extradata[stream], size);
00445     return 0;
00446 }
00447 
00448 static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
00449 {
00450     FLVContext *flv = s->priv_data;
00451     int ret, i, type, size, flags;
00452     int stream_type=-1;
00453     int64_t next, pos;
00454     int64_t dts, pts = AV_NOPTS_VALUE;
00455     int av_uninit(channels);
00456     int av_uninit(sample_rate);
00457     AVStream *st = NULL;
00458 
00459  for(;;avio_skip(s->pb, 4)){ /* pkt size is repeated at end. skip it */
00460     pos = avio_tell(s->pb);
00461     type = avio_r8(s->pb);
00462     size = avio_rb24(s->pb);
00463     dts = avio_rb24(s->pb);
00464     dts |= avio_r8(s->pb) << 24;
00465     av_dlog(s, "type:%d, size:%d, dts:%"PRId64"\n", type, size, dts);
00466     if (url_feof(s->pb))
00467         return AVERROR_EOF;
00468     avio_skip(s->pb, 3); /* stream id, always 0 */
00469     flags = 0;
00470 
00471     if(size == 0)
00472         continue;
00473 
00474     next= size + avio_tell(s->pb);
00475 
00476     if (type == FLV_TAG_TYPE_AUDIO) {
00477         stream_type=FLV_STREAM_TYPE_AUDIO;
00478         flags = avio_r8(s->pb);
00479         size--;
00480     } else if (type == FLV_TAG_TYPE_VIDEO) {
00481         stream_type=FLV_STREAM_TYPE_VIDEO;
00482         flags = avio_r8(s->pb);
00483         size--;
00484         if ((flags & 0xf0) == 0x50) /* video info / command frame */
00485             goto skip;
00486     } else if (type == FLV_TAG_TYPE_META) {
00487         if (size > 13+1+4 && dts == 0) { // Header-type metadata stuff
00488             flv_read_metabody(s, next);
00489             goto skip;
00490         } else if (dts != 0) { // Script-data "special" metadata frames - don't skip
00491             stream_type=FLV_STREAM_TYPE_DATA;
00492         } else {
00493             goto skip;
00494         }
00495     } else {
00496         av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
00497     skip:
00498         avio_seek(s->pb, next, SEEK_SET);
00499         continue;
00500     }
00501 
00502     /* skip empty data packets */
00503     if (!size)
00504         continue;
00505 
00506     /* now find stream */
00507     for(i=0;i<s->nb_streams;i++) {
00508         st = s->streams[i];
00509         if (st->id == stream_type)
00510             break;
00511     }
00512     if(i == s->nb_streams){
00513         av_log(s, AV_LOG_WARNING, "Stream discovered after head already parsed\n");
00514         st= create_stream(s, stream_type);
00515     }
00516     av_dlog(s, "%d %X %d \n", stream_type, flags, st->discard);
00517     if(  (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY || (stream_type == FLV_STREAM_TYPE_AUDIO)))
00518        ||(st->discard >= AVDISCARD_BIDIR  &&  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && (stream_type == FLV_STREAM_TYPE_VIDEO)))
00519        || st->discard >= AVDISCARD_ALL
00520        ){
00521         avio_seek(s->pb, next, SEEK_SET);
00522         continue;
00523     }
00524     if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
00525         av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME);
00526     break;
00527  }
00528 
00529     // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
00530     if(s->pb->seekable && (!s->duration || s->duration==AV_NOPTS_VALUE)){
00531         int size;
00532         const int64_t pos= avio_tell(s->pb);
00533         const int64_t fsize= avio_size(s->pb);
00534         avio_seek(s->pb, fsize-4, SEEK_SET);
00535         size= avio_rb32(s->pb);
00536         avio_seek(s->pb, fsize-3-size, SEEK_SET);
00537         if(size == avio_rb24(s->pb) + 11){
00538             uint32_t ts = avio_rb24(s->pb);
00539             ts |= avio_r8(s->pb) << 24;
00540             s->duration = ts * (int64_t)AV_TIME_BASE / 1000;
00541         }
00542         avio_seek(s->pb, pos, SEEK_SET);
00543     }
00544 
00545     if(stream_type == FLV_STREAM_TYPE_AUDIO){
00546         int bits_per_coded_sample;
00547         channels    = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
00548         sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
00549         bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
00550         if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) {
00551             st->codec->channels              = channels;
00552             st->codec->sample_rate           = sample_rate;
00553             st->codec->bits_per_coded_sample = bits_per_coded_sample;
00554         }
00555         if(!st->codec->codec_id){
00556             flv_set_audio_codec(s, st, st->codec, flags & FLV_AUDIO_CODECID_MASK);
00557             flv->last_sample_rate = st->codec->sample_rate;
00558             flv->last_channels    = st->codec->channels;
00559         } else {
00560             AVCodecContext ctx;
00561             ctx.sample_rate = sample_rate;
00562             flv_set_audio_codec(s, st, &ctx, flags & FLV_AUDIO_CODECID_MASK);
00563             sample_rate = ctx.sample_rate;
00564         }
00565     } else if(stream_type == FLV_STREAM_TYPE_VIDEO) {
00566         size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
00567     }
00568 
00569     if (st->codec->codec_id == CODEC_ID_AAC ||
00570         st->codec->codec_id == CODEC_ID_H264 ||
00571         st->codec->codec_id == CODEC_ID_MPEG4) {
00572         int type = avio_r8(s->pb);
00573         size--;
00574         if (st->codec->codec_id == CODEC_ID_H264 || st->codec->codec_id == CODEC_ID_MPEG4) {
00575             int32_t cts = (avio_rb24(s->pb)+0xff800000)^0xff800000; // sign extension
00576             pts = dts + cts;
00577             if (cts < 0) { // dts are wrong
00578                 flv->wrong_dts = 1;
00579                 av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n");
00580             }
00581             if (flv->wrong_dts)
00582                 dts = AV_NOPTS_VALUE;
00583         }
00584         if (type == 0 && !st->codec->extradata) {
00585             if (st->codec->extradata) {
00586                 if ((ret = flv_queue_extradata(flv, s->pb, stream_type, size)) < 0)
00587                     return ret;
00588                 ret = AVERROR(EAGAIN);
00589                 goto leave;
00590             }
00591             if ((ret = flv_get_extradata(s, st, size)) < 0)
00592                 return ret;
00593             if (st->codec->codec_id == CODEC_ID_AAC) {
00594                 MPEG4AudioConfig cfg;
00595                 if (avpriv_mpeg4audio_get_config(&cfg, st->codec->extradata,
00596                                              st->codec->extradata_size * 8, 1) >= 0) {
00597                 st->codec->channels = cfg.channels;
00598                 if (cfg.ext_sample_rate)
00599                     st->codec->sample_rate = cfg.ext_sample_rate;
00600                 else
00601                     st->codec->sample_rate = cfg.sample_rate;
00602                 av_dlog(s, "mp4a config channels %d sample rate %d\n",
00603                         st->codec->channels, st->codec->sample_rate);
00604                 }
00605             }
00606 
00607             ret = AVERROR(EAGAIN);
00608             goto leave;
00609         }
00610     }
00611 
00612     /* skip empty data packets */
00613     if (!size) {
00614         ret = AVERROR(EAGAIN);
00615         goto leave;
00616     }
00617 
00618     ret= av_get_packet(s->pb, pkt, size);
00619     if (ret < 0) {
00620         return AVERROR(EIO);
00621     }
00622     /* note: we need to modify the packet size here to handle the last
00623        packet */
00624     pkt->size = ret;
00625     pkt->dts = dts;
00626     pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts;
00627     pkt->stream_index = st->index;
00628     if (flv->new_extradata[stream_type]) {
00629         uint8_t *side = av_packet_new_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
00630                                                 flv->new_extradata_size[stream_type]);
00631         if (side) {
00632             memcpy(side, flv->new_extradata[stream_type],
00633                    flv->new_extradata_size[stream_type]);
00634             av_freep(&flv->new_extradata[stream_type]);
00635             flv->new_extradata_size[stream_type] = 0;
00636         }
00637     }
00638     if (stream_type == FLV_STREAM_TYPE_AUDIO && (sample_rate != flv->last_sample_rate ||
00639                      channels != flv->last_channels)) {
00640         flv->last_sample_rate = sample_rate;
00641         flv->last_channels    = channels;
00642         ff_add_param_change(pkt, channels, 0, sample_rate, 0, 0);
00643     }
00644 
00645     if (    stream_type == FLV_STREAM_TYPE_AUDIO ||
00646             ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY) ||
00647             stream_type == FLV_STREAM_TYPE_DATA)
00648         pkt->flags |= AV_PKT_FLAG_KEY;
00649 
00650 leave:
00651     avio_skip(s->pb, 4);
00652     return ret;
00653 }
00654 
00655 static int flv_read_seek(AVFormatContext *s, int stream_index,
00656     int64_t ts, int flags)
00657 {
00658     return avio_seek_time(s->pb, stream_index, ts, flags);
00659 }
00660 
00661 #if 0 /* don't know enough to implement this */
00662 static int flv_read_seek2(AVFormatContext *s, int stream_index,
00663     int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
00664 {
00665     int ret = AVERROR(ENOSYS);
00666 
00667     if (ts - min_ts > (uint64_t)(max_ts - ts)) flags |= AVSEEK_FLAG_BACKWARD;
00668 
00669     if (!s->pb->seekable) {
00670         if (stream_index < 0) {
00671             stream_index = av_find_default_stream_index(s);
00672             if (stream_index < 0)
00673                 return -1;
00674 
00675             /* timestamp for default must be expressed in AV_TIME_BASE units */
00676             ts = av_rescale_rnd(ts, 1000, AV_TIME_BASE,
00677                 flags & AVSEEK_FLAG_BACKWARD ? AV_ROUND_DOWN : AV_ROUND_UP);
00678         }
00679         ret = avio_seek_time(s->pb, stream_index, ts, flags);
00680     }
00681 
00682     if (ret == AVERROR(ENOSYS))
00683         ret = av_seek_frame(s, stream_index, ts, flags);
00684     return ret;
00685 }
00686 #endif
00687 
00688 AVInputFormat ff_flv_demuxer = {
00689     .name           = "flv",
00690     .long_name      = NULL_IF_CONFIG_SMALL("FLV format"),
00691     .priv_data_size = sizeof(FLVContext),
00692     .read_probe     = flv_probe,
00693     .read_header    = flv_read_header,
00694     .read_packet    = flv_read_packet,
00695     .read_seek = flv_read_seek,
00696 #if 0
00697     .read_seek2 = flv_read_seek2,
00698 #endif
00699     .read_close = flv_read_close,
00700     .extensions = "flv",
00701     .value = CODEC_ID_FLV1,
00702 };