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• How to play video through framebuffer device and audio through pulseaudio (simultaneously)

  5 août 2019, par waterj

  I have a video/audio file called test_video.mp4 that I want the video component of to stream to /dev/fb0 and the audio component of to stream to pulseaudio using ffmpeg. This is so that I can play the file on a piece of custom hardware running Alpine through an HDMI connection to a monitor with speakers.

  I know this is pretty bad, but I wiped the virtual machine I tried doing this on, so I don’t have a record of the commands I’ve tried. I’m open to any and all suggestions, though !

• How can I play .sdp file with vlc player ?

  27 février 2018, par NGMong

  I created the .sdp file locally using ffmpeg,
  Try to play through vlc on Android.
  I tried to play through vlc, but the video does not come out.
  Below is my sdp file

  v = 0

  o = - 0 0 IN IP4 127.0.0.1

  s = H.264 Video, streamed by the LIVE555 Media Server

  c = IN IP4 127.0.0.1

  t = 0 0

  a = tool : libavformat 57.71.100

  video 10000 RTP / AVP 96

  b = AS : 900

  a = rtpmap : 96 H264 / 90000

  a = fmtp : 96 packetization-mode = 1 ;

  sprop-parameter-sets = Z00AH42kBQF / ywBA,

  aO48gA == ; profile-level-id = 4D001F

  vel-id = 4D001F

  The code played through vlc is shown below.

  try {
  
              if (media.length() > 0) {
  
                  Toast toast = Toast.makeText(this, media,Toast.LENGTH_LONG);
  
                  toast.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0,
  
                          0);
  
                  toast.show();
  
              }
  
              // Create LibVLC
  
              // TODO: make this more robust, and sync with audio demo
  
              ArrayList<string> options = new ArrayList<string>();
  
              //options.add("--subsdec-encoding <encoding>");
  
              options.add("--aout=opensles");
  
              options.add("--audio-time-stretch"); // time stretching
  
              options.add("-vvv"); // verbosity
  
              //options.add("vlc -vvv @ : 5004");
  
              libvlc = new LibVLC(this, options);
  
              holder.setKeepScreenOn(true);
  
  
  
              // Creating media player
  
              mMediaPlayer = new MediaPlayer(libvlc);
  
              mMediaPlayer.setEventListener(mPlayerListener);
  
  
  
              // Seting up video output
  
              final IVLCVout vout = mMediaPlayer.getVLCVout();
  
              vout.setVideoView(mSurface);
  
              //vout.setSubtitlesView(mSurfaceSubtitles);
  
              vout.addCallback(this);
  
              vout.attachViews();
  
              Log.e(TAG, "URI ::  "+Uri.parse(media));
  
              Media m = new Media(libvlc, Uri.parse(media));
  
              mMediaPlayer.setMedia(m);
  
              mMediaPlayer.play();
  
          } catch (Exception e) {
  
              Toast.makeText(this, "Error in creating player!", Toast
  
                      .LENGTH_LONG).show();
  
          }
  
  </encoding></string></string>

  What is the problem ?

• How to play video Media Source Extensions when the audio start is delayed ? Or how to fix it with ffmpeg ?

  11 décembre 2020, par sheodox

  I have a video that I'm splitting the individual video/audio streams out then dashing with MP4Box, then I'm playing them with Media Source Extensions and appending byte ranges to video/audio source buffers from the MPD files. It's all working nicely, but one video I have has audio that is delayed by about 1.1 second. I couldn't get it to sync up and the audio would always play ahead of the video.

  


  Currently I'm trying to set the audioBuffer.timestampOffset = 1.1 and that gets it to sync up perfectly. The issue I'm running into now though is the video refuses to play unless the audio source buffer has data. So the video stalls right away. If I skip a few seconds in (past the offset) everything works because both video/audio are buffered.

  


  Is there a way to get around this ? Either make it play without the audio loaded, somehow fill the audio buffer with silence (can I generate something with the Web Audio API) ? Add silence to the audio file in ffmpeg ? Something else ?

  


  I first tried adding a delay in ffmpeg with ffmpeg -i video.mkv -map 0:a:0 -acodec aac -af "adelay=1.1s:all=true" out.aac but nothing seemed to change. Was I doing something wrong ? Is there a better way to demux audio while keeping the exact same timing as when it was in the container with the video so I don't have to worry about delays/offsets at all ?