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• How to record a video conference (e.g skype, oovoo, ...) with a program written in C#

  13 août 2014, par Matin Lotfaliee

  I want to record screen (a video conference e.g skype, oovoo, ...) with a program written in C#. I searched a lot about how to do this :

  • Here suggests Windows Media Encoder, but none of their samples work correctly on my Win7. I installed the SDK but even the links to Microsoft are somehow broken or old.
  • Here suggests creating a video stream from a series of screenshots using ffmpeg. but it is probably impossible to keep the audio,mic and screenshots synced.
  • Here suggests creating a GIF file, but it does not support audio which is important to me.
  • Here suggess using Gallio framework, but I was unable to find where the usable DLL for recording is.
  • Here seems to be a great solution but it is not free...

  Compression is not important to me because a video conference uses CPU a lot.

  Can you help me find a good and easy solution with references ?

• MPEG DASH : Playing video segments from .m4s files instead of byte ranges in the MPD File using Simple DASH Player

  1er novembre 2018, par Trycoder

  I have followed the tutorial from the link below to create an MPEG DASH player using HTML5 and javascript.
  Building a simple MPEG dash player using HTML5 and JS.

  In the given tutorial, it is possible to play the video segments using byte ranges. But for my application, I need the following features.

  1. The video player should read the .m4s segment files and play the video instead of byte ranges.
  2. The amount of data in the MediaSource buffer should be calculated periodically, also the amount of space left in the buffer.

  Are these possible in the given player or Is there a better MPEG DASH Player with the above features ?

  PS : The MPD File is created using FFmpeg.

  ffmpeg  -f  avfoundation -video_size 1280x720 -framerate 30 -i 0 -vcodec libx264  -acodec aac  -b:v 800k  -f dash  -use_template 0  -min_seg_duration 4000 -single_file 1  -start_at_zero -live 1  ffmpeg.mpd

  Also, I tried using the DASH.js player but the documentation is very vast in it. Can we get the size of the source buffer in dash.js (The space available in the source buffer and also the amount of space filled) ? This is the main feature which is required for my project.

  Edit :
  Code which I tried

• 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 ?