Recherche avancée

Sur d’autres sites (10191)

• Using ffmpeg, I'm trying to mute all 5.1 channels of audio for a period of time within a video

  1er novembre 2019, par cozmonaut

  I’m wanting to mute audio for a portion of a video clip while keeping the video exactly as it is.

  I came across this online.

  ffmpeg -i ~/Downloads/in.mov -vcodec copy -af "volume=enable='between(t,0,3)':volume=0" ~/Downloads/out2.mov

  Although it works, it converts the 5.1 audio to stereo. Isn’t it possible to mute the first 3 seconds of all 5.1 channels of audio, while keeping the 5.1 channels intact within the finished output video file ?

  Here are the specs on my video/audio clip :

  Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(progressive), 1280x720 [SAR 1:1 DAR 16:9], Closed Captions, 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc
  
  Stream #0:1[0x101]: Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz, stereo, fltp, 192 kb/s
  
  Stream #0:2[0x102]: Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz, 5.1(side), fltp, 384 kb/s

  Thank you.

• how to resume ffmpeg streamer for network disconnection for a period of time but eventually recovery

  30 septembre 2019, par DJI_lover

  I can stream my video well by using ffmpeg’s libav* when network is good，but I can not guarantee that the network will always be good.I hope that when the network is bad, even disconnect for a period of time, the streaming process can resume and continue to stream video when network recover. I have tried, when I was streaming the video, I manually disconnected the network, the streamer stopped quickly. After 20 seconds, I resumed the network, the process resumed to stream as well in a few seconds.But if I disconnect the network for five minutes or longer, when the network is restored, the process blocked.Dose someone knows how to resume the streamer instread of blocking no matter how long the network is disconnected but eventually recovered（not by restarting the program）.Could you give me some solution if you know ，thanks .

  I have googled the solution,but can’t find something useful.So I come here to ask for help

  static int encode_and_write_frame(AVCodecContext *codec_ctx, AVFormatContext *fmt_ctx, AVFrame *frame)
  
  {
  
      AVPacket pkt = {0};
  
      av_init_packet(&pkt);
  
      int ret = avcodec_send_frame(codec_ctx, frame);
  
      if (ret < 0)
  
      {
  
          fprintf(stderr, "Error sending frame to codec context!\n");
  
          return ret;
  
      }
  
      ret = avcodec_receive_packet(codec_ctx, &pkt);
  
      //pkt.dts = pkt.pts;
  
      if (ret < 0)
  
      {
  
          fprintf(stderr, "Error receiving packet from codec context!\n" );
  
          return ret;
  
      }
  
      av_interleaved_write_frame(fmt_ctx, &pkt);
  
      av_packet_unref(&pkt);
  
      return 0;
  
  }
  
  
  
  
  
  void Streamer::stream_frame(const cv::Mat &image)
  
  {
  
      if(can_stream()) {
  
          const int stride[] = {static_cast<int>(image.step[0])};
  
          sws_scale(scaler.ctx, &amp;image.data, stride, 0, image.rows, picture.frame->data, picture.frame->linesize);
  
          picture.frame->pts += av_rescale_q(1, out_codec_ctx->time_base, out_stream->time_base);
  
   //picture.frame->dts = picture.frame->pts;
  
          encode_and_write_frame(out_codec_ctx, format_ctx, picture.frame);
  
      }
  
  }
  
  
  
  
  
  while(ok) {
  
          process_frame(read_frame, proc_frame);
  
          if(!from_camera) {
  
              streamer.stream_frame(proc_frame);
  
          } else {
  
              streamer.stream_frame(proc_frame, frame_time.count()*streamer.inv_stream_timebase);
  
          }
  
          ok = video_capture.read(read_frame);
  
          time_prev = time_stop;
  
      }
  
  </int>

• Can not set period/timeout option for ffmepg

  26 août 2019, par newBike

  I tried to capture streaming via rtsp and limit the clip duration under 3 sec

  But the option doesn’t work. The ffmpeg won’t be terminated anymore.

  Is there any workaround to fix the problem.

  Because I have to run hundreds of similar commands in a batch with Python script.

  ffmpeg -loglevel verbose   -i rtsp://172.19.1.42/live.sdp -acodec copy -vcodec copy  c0_s1_h264_640x480_30_vbr_500_99_40000000.mp4 -timeout 3 -y

  $ ffmpeg -h ffmpeg version 1.2.4 Copyright (c) 2000-2013 the FFmpeg
  developers built on Nov 22 2013 11:59:59 with Apple LLVM version 5.0
  (clang-500.2.79) (based on LLVM 3.3svn)

  The detailed log at https://gist.github.com/poc7667/8234701