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• Put remaining pieces of CODEC_FLAG_EMU_EDGE under FF_API_EMU_EDGE.

  17 août 2015, par Ronald S. Bultje

  Put remaining pieces of CODEC_FLAG_EMU_EDGE under FF_API_EMU_EDGE.
  The amv one probably looks suspicious, but since it’s an intra-only
  
  codec, I couldn’t possibly imagine what it would use the edge for,
  
  and the vsynth fate result doesn’t change, so it’s probably OK.
  

  • [DH] ffmpeg_opt.c
  • [DH] ffplay.c
  • [DH] libavcodec/mjpegenc.c
  • [DH] libavcodec/snowenc.c
  • [DH] libavcodec/wmv2dec.c

• How to create video and audio files for the Media Source Extension API ?

  5 décembre 2018, par Aman

  I have created a video player from the Media Source Extension API. I have split the video and audio from the original.mp4 (1 minute duration). I have split the video and audio into small 5 second files (12 files in total). I’m getting each one of them and playing them together. But the video stops playing at around 45-47 seconds. I cannot understand to why the video is stopping/buffering. I cannot understand whether the problem is in the javascript code or the video files ?

  I have uploaded all the resources here (https://drive.google.com/file/d/1NHc_yNRU0tvaU18aohLy74Js3y7UHD4N/view?usp=sharing). And written the commands I used to construct my video and audio files below. I have also noticed that this problem only occurs with Google Chrome and works perfectly and smoothly on Microsoft Edge. Thanks

  Making the Media files:

  Extracting video from original.mp4: MP4Box -single 1 original.mp4

  Extracting audio from original.mp4: MP4Box -single 2 original.mp4

  Splitting the video and audio into 5 second parts: ffmpeg -ss starting-time -to end-time -i (video.mp4 OR audio.mp4) (video_part.mp4 OR audio_part.mp4)

  Fragmenting all the video and audio parts: MP4Box -dash 1000 -rap -frag-rap(video_part.mp4 OR audio_part.mp4)

  Then using the fragmented video and audio files to be played via the Media Source Extension API video player. e.g. (video_part_dashinit.mp4 OR audio_part_dashinit.mp4)

• Low latency video streaming on android

  17 mai 2021, par Louis Blenner

  I'd like to be able to stream the video from my webcam to an Android app with a latency below 500ms, on my local network.

  


  To capture and send the video over the network, I use ffmpeg.

  


  ffmpeg -f v4l2 -i /dev/video0 -preset ultrafast -tune zerolatency -vcodec libx264 -an -vf format=yuv420p -f mpegts  udp://192.168.1.155:5000


  


  This command takes the webcam as an input, convert it and send it to a device using the mpegts protocol.

  


  I am able to read the video on another PC with a latency below 500 ms, using commands like

  


  gst-launch-1.0 -v udpsrc port=5000 ! video/mpegts ! tsdemux ! h264parse ! avdec_h264 ! fpsdisplaysink sync=false


  


  or

  


  mpv udp://0.0.0.0:5000 --no-cache --untimed --no-demuxer-thread --video-sync=audio --vd-lavc-threads=1 


  


  So it is possible to have this range of latency.
  
I'd like to have the same thing on Android.

  


  Here are my tries to do that.

  


  Exoplayer

  


  After looking at the different players available on Android studio, it seems like Exoplayer is the go-to choice.
  
I tried different options indicated in the live-streaming documentation, but I always end up with a stream taking seconds to start and with a latency of seconds.
  
I tried to add a Button to seek to the default position of the windows, but it results in a loading of several seconds.

  


  DefaultExtractorsFactory extractorsFactory =
                new DefaultExtractorsFactory()
                        .setTsExtractorFlags(DefaultTsPayloadReaderFactory.FLAG_IGNORE_AAC_STREAM);

        player = new SimpleExoPlayer.Builder(this)
                .setMediaSourceFactory(
                        new DefaultMediaSourceFactory(this, extractorsFactory))
                .setLoadControl(new DefaultLoadControl.Builder()
                        .setBufferDurationsMs(DefaultLoadControl.DEFAULT_MIN_BUFFER_MS, DefaultLoadControl.DEFAULT_MAX_BUFFER_MS, 200, 200)
                        .build())
                .build();
        MyPlayerView playerView = findViewById(R.id.player_view);
        // Bind the player to the view.
        playerView.setPlayer(player);
        // Build the media item.
        MediaItem mediaItem = new MediaItem.Builder()
                .setUri(Uri.parse("udp://0.0.0.0:5000"))
                .setLiveMaxOffsetMs(500)
                .setLiveTargetOffsetMs(0)
                .setLiveMinOffsetMs(0)
                .build();
        // Set the media item to be played.
        player.setMediaItem(mediaItem);
        // Prepare the player.
        player.setPlayWhenReady(true);
        player.prepare();
        //player.seekToDefaultPosition();


  


  This issue is about the same issue and the conclusion was that Exoplayer was not fit for this use case.

  


  


  I'll be honest, ultra low-latency like this isn't ExoPlayer's main use-case

  


  


  Vlc

  


  Another try was to use the Vlc library.
  
But I was unable to have the same low latency stream as with the two previous example with Vlc.
  
I tried changing the preferences of Vlc to stream as fast as possible.

  


  Input/Codecs -> x264 preset: ultrafast - zerolatency
Input/Codecs -> Access Module: UDP input
Input/Codecs -> Clock Jitter: 500
Audio: disable audio


  


  I also tried reducing the different buffers.
  
However, I still have a latency of more than 1 seconds with that.

  


  Gstreamer

  


  Another try was to create a react-native project to use the different players available here.
  
One player that seemed promising was react-native-gstreamer because it uses gstreamer which is able to stream with low latency (gst-launch command).
  
But the library is now outdated.

  


  Question

  


  There were other tries, but none were successful.
  
Is there a problem with one of my approaches ?
  
And if not, Is there a player on Android (that I missed) which is able to achieve low latency stream like gstream or mpv on linux ?