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 * https://stackoverflow.com/questions/33747500/using-gstreamer-to-capture-screen-and-show-it-in-a-window/33822024#33822024
  36 * http://www.einarsundgren.se/gstreamer-basic-real-time-streaming-tutorial/
  37 * https://gist.github.com/tetkuz/0c038321d05586841897
  38 * https://gist.github.com/esrever10/7d39fe2d4163c5b2d7006495c3c911bb
  39 * https://gist.github.com/nebgnahz/26a60cd28f671a8b7f522e80e75a9aa5
  40 * https://salsa.debian.org/debconf-video-team/ansible/-/blob/master/roles/voctomix/templates/videoteam-stream.j2
  41 * https://github.com/xfxf/video-scripts/blob/master/michael/youtube-live.sh
  42   (and others in the same repo)
  43
  44 # VLC
  45 Note that you have to close VLC and open it again for new streaming as VLC leaves the connections
  46 open (I spent hours figuring out why http based streaming doesn't work - `netstat -4 --ip` is nice
  47 for debugging in that respect).
  48
  49 ## RTP
  50 ### Source
  51 The address has to be the address where the video should be streamed **to**. In the following
  52 examples, a multicast address is used. It is either the IP address of the device receiving the video (unicast address) or a multicast address
  53 like 239.255.12.42 (multicast addresses are between 224.0.0.0 and 239.255.255.255, some of
  54 them being reserved, 239.0.0.0 to 239.255.255.255 are Organization-Local Scope so they are
  55 good candidates, see
  56 https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml).
  57
  58     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
  59     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
  60     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
  61     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
  62
  63 ### Player
  64     cvlc rtp://239.255.12.42
  65
  66
  67 ## RTSP
  68 For VLC, RTSP means RTSP combined with RTP.
  69
  70 ### Source
  71 We assume that the video source computer has the external IP 192.168.1.54.
  72 Instead of rtsp://192.168.1.54:8554/ we could also use rtsp://192.168.1.54:8554/mystream.sdp
  73
  74     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
  75     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
  76
  77
  78 ### Player
  79 The address needs to be the address of the source. Note the backslash at the end.
  80
  81     vlc rtsp://192.168.1.54:8554/
  82
  83
  84 ## VLC Remarks
  85 * Latency: The following options are said to reduce latency:
  86
  87       --network-caching=150 --clock-jitter=0 --clock-synchro=0
  88
  89 * Duplicating a stream is nice for debugging:
  90
  91       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
  92       cvlc rtp://239.255.12.42
  93
  94
  95 ## HTTP
  96 The address at the source side has to be the external one of the local computer.
  97
  98 ### Source (server)
  99     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
 100
 101 ### Player (client)
 102
 103     vlc http://192.168.1.54:8080
 104
 105
 106 # Kodi
 107 The player built into code knows at least the following streaming protocols: http, rtsp.
 108
 109 https://kodi.wiki/index.php?title=Internet_video_and_audio_streams