stream2beamer.md

   1 # Stream Desktop/Video/Webcam to Kodi/Beamer/other PCs
   2 Gregor and I had a closer look at the following projects:
   3
   4 # Laplace
   5 Simple WebRTC implementation in GO: https://github.com/adamyordan/laplace.git
   6 Simple to compile and just works.
   7 WebRTC actually uses SRTP (Secure Real-time Transport Protocol).
   8
   9 IPv6+IPv4, and no TLS:
  10
  11     ./laplace -addr "[::]:8080" -tls=false
  12
  13 # gstreamer
  14 * Supports RTP
  15 * Supports webcam capture via v4l (video for linux)
  16 * Supports screen capture via xmanager/ximagesrc
  17 * Interesting URLs:
  18   * WebRTC in one direction only: https://stackoverflow.com/questions/57430215/how-to-use-webrtcbin-create-offer-only-receive-video
  19   * gstreamer to VLC via RTP: https://stackoverflow.com/questions/13154983/gstreamer-rtp-stream-to-vlc
  20   * https://github.com/intel/gstreamer-media-SDK/issues/138
  21   * https://developer.ridgerun.com/wiki/index.php?title=GstWebRTC_Pipelines
  22   * https://developer.ridgerun.com/wiki/index.php?title=GstWebRTC_-_H264-Opus_Examples#Receive_Pipeline
  23
  24 ## WebRTC
  25 gstreamer has a WebRTC implementation.
  26 The examples at https://github.com/centricular/gstwebrtc-demos.git work once
  27
  28     export OPENSSL_CONF=''
  29
  30 has been set (see https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/issues/811)
  31
  32 ## gstreamer examples
  33     gst-launch-1.0 -v playbin uri=file:///home/philipp/tmp/GerisGame.mp4
  34
  35
  36 # VLC
  37 Note that you have to close VLC and open it again for new streaming as VLC leaves the connections
  38 open (I spent hours figuring out why http based streaming doesn't work - `netstat -4 --ip` is nice
  39 for debugging in that respect).
  40
  41 ## RTP
  42 ### Source
  43 The address has to be the address where the video should be streamed **to**. In the following
  44 examples, a multicast address is used. It is either the IP address of the device receiving the video (unicast address) or a multicast address
  45 like 239.255.12.42 (multicast addresses are between 224.0.0.0 and 239.255.255.255, some of
  46 them being reserved, 239.0.0.0 to 239.255.255.255 are Organization-Local Scope so they are
  47 good candidates, see
  48 https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml).
  49
  50     cvlc -vv --sout '#transcode{vcodec=h264,acodec=mpga,channels=2,vb=800,ab=128}:rtp{mux=ts,dst=239.255.12.42,sdp=sap,name="Geris Game"}' GerisGame.mp4
  51     cvlc -vv --sout '#transcode{vcodec=h264,acodec=mpga,ab=128,channels=2,samplerate=44100,scodec=none}:rtp{dst=239.255.12.42,port=5004,mux=ts,sap,name=Geris Game}' :no-sout-all :sout-keep GerisGame.mp4
  52     cvlc -vv --sout '#transcode{vcodec=h264,acodec=mpga,channels=2}:rtp{mux=ts,dst=239.255.12.42,sdp=sap,name="Videokamera"}' v4l2:///dev/video0 # long latency
  53     cvlc -vv --sout '#transcode{vcodec=h264,acodec=mpga,channels=2}:rtp{mux=ts,dst=239.255.12.42,sdp=sap,name="Desktop"}' screen:// # not convincing
  54
  55 ### Player
  56     cvlc rtp://239.255.12.42
  57
  58
  59 ## RTSP
  60 For VLC, RTSP means RTSP combined with RTP.
  61
  62 ### Source
  63 We assume that the video source computer has the external IP 192.168.1.54.
  64 Instead of rtsp://192.168.1.54:8554/ we could also use rtsp://192.168.1.54:8554/mystream.sdp
  65
  66     cvlc -vv --sout '#transcode{vcodec=h264,acodec=mpga,ab=128,channels=2,samplerate=44100,scodec=none}:rtp{sdp=rtsp://:8554/}' :no-sout-all :sout-keep GerisGame.mp4
  67     cvlc -vv --sout '#rtp{dst=239.255.12.42,port=1234,sdp=rtsp://192.168.1.54:8554/}' :no-sout-all :sout-keep GerisGame.mp4
  68
  69
  70 ### Player
  71 The address needs to be the address of the source. Note the backslash at the end.
  72
  73     vlc rtsp://192.168.1.54:8554/
  74
  75
  76 ## VLC Remarks
  77 * Latency: The following options are said to reduce latency:
  78
  79       --network-caching=150 --clock-jitter=0 --clock-synchro=0
  80
  81 * Duplicating a stream is nice for debugging:
  82
  83       cvlc -vv --sout '#duplicate{dst=display,dst="transcode{vcodec=h264,acodec=mpga,channels=2,vb=800,ab=128}:rtp{mux=ts,dst=239.255.12.42,sdp=sap,name=Geris Game}"}' GerisGame.mp4
  84       cvlc rtp://239.255.12.42
  85
  86
  87 ## HTTP
  88 The address at the source side has to be the external one of the local computer.
  89
  90 ### Source (server)
  91     cvlc -vv --sout '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:standard{access=http,mux=ogg,dst=0.0.0.0:8080}' GerisGame.mp4
  92
  93 ### Player (client)
  94
  95     vlc http://192.168.1.54:8080
  96
  97
  98 # Kodi
  99 The player built into code knows at least the following streaming protocols: http, rtsp.
 100
 101 https://kodi.wiki/index.php?title=Internet_video_and_audio_streams