Recherche avancée

Sur d’autres sites (16700)

• mpeg12dec : Extract CC user data into frame side data

  26 novembre 2013, par John Stebbins

  mpeg12dec : Extract CC user data into frame side data
  Signed-off-by : Anton Khirnov <anton@khirnov.net>
  

  • [DBH] doc/APIchanges
  • [DBH] libavcodec/mpeg12dec.c
  • [DBH] libavutil/frame.h
  • [DBH] libavutil/version.h

• How to save data of packet.data using ffmpeg && c language ?

  12 juin 2015, par patrick

  I’m try to build an app in c that extract audio from video and save it as audio file. I’m able to extract the audio but now the problem is how to save it. I wrote the code given below but it’s giving me an segmentation fault. Thanks in advance.

  My code is :

  AVOutputFormat* fmt = av_guess_format("mp3", NULL, NULL);;
  
  AVFormatContext* oc = avformat_alloc_context();
  
  oc->oformat = fmt;
  
  avio_open2(&oc->pb, "test.mp3", AVIO_FLAG_WRITE,NULL,NULL);
  
  
  
  AVStream* stream=NULL;
  
  int cnt = 0;
  
  
  
  while(av_read_frame(pFormatCtx, &packet)>=0) { //pFormatCtx is input file format context.
  
      if (packet.stream_index==audioStream) {
  
      int got_frame = 0;
  
      if (avcodec_decode_audio4(pCodecCtx, pFrame, &got_frame, &packet) < 0) {
  
          fprintf(stderr, "Error encoding frame\n");
  
                  exit(1);
  
          }
  
  
  
          if(got_frame) {
  
          if (av_interleaved_write_frame(oc, &packet) < 0) {
  
                  printf(stderr, "Error writing frame\n");
  
                      exit(1);
  
                  }
  
          }
  
      }
  
      av_free_packet(&packet);
  
      av_init_packet(&packet);
  
  }

• Reading RTMP streams using FFMPEG returns AVERROR_EOF randomly

  9 octobre 2013, par user2628781

  I am using FFMpeg to receive RTMP streams. This logic is placed in a custom video player I am building.

  I managed to successfully connect to the RTMP stream and display the video correctly. However, after a period in time, the stream terminates prematurely with an AVERROR_EOF when I perform av_read_frame().

  This indicates to me that the file has ended so my demux, video and audio threads terminates thinking that the video has ended.
  However, the video playback hasn't yet reached its end (in the case of a file streamed through rtmp) or from a live stream (which runs forever). The EOFs are received very randomly so it may run for say 7 min before this occurs or after 3 mins.

  Is this a characteristic behaviour of RTMP or am I doing something incorrectly ?
  I am also having a similar problem with Http Live Streams using FFMpeg.

  A small snippet of the code is provided below :

   AVPacket packet;
  
  //start timeout timer and timeout
  
  __interrupt_timer.start();
  
  
  
  int ret = av_read_frame(format_context, &packet); //0: ok, <0: error/end
  
  
  
  
  
  //invalidate the timer
  
  __interrupt_timer.invalidate();
  
  
  
  if (ret != 0) {
  
      if (ret == AVERROR_EOF) { //end of file. FIXME: why no eof if replaying by seek(0)?            
  
          if (!eof) {
  
              eof = true;
  
              started_ = false;
  
              pkt->data = QByteArray(); //flush
  
              pkt->markEnd();
  
              qDebug("End of file. %s %d", __FUNCTION__, __LINE__);
  
              emit finished();
  
              return true;
  
          }
  
          pkt->data = QByteArray(); //flush
  
          //return true;
  
          return false; //frames after eof are eof frames
  
      } else if (ret == AVERROR_INVALIDDATA) {
  
          qWarning("AVERROR_INVALIDDATA");
  
      } else if (ret == AVERROR(EAGAIN)) {
  
          return true;
  
      }
  
      qWarning("[AVDemuxer] error: %s", av_err2str(ret));
  
      return false;
  
  }