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     # send
  36     gst-launch-1.0 ximagesrc ! videoconvert ! videoscale ! video/x-raw,width=800,height=600 ! vp8enc ! rtpvp8pay ! udpsink host=239.255.12.42 port=5004
  37     # receive
  38     gst-launch-1.0 udpsrc address=239.255.12.42 port=5004 caps="application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)VP8-DRAFT-IETF-01, payload=(int)96, ssrc=(uint)2990747501, clock-base=(uint)275641083, seqnum-base=(uint)34810" ! rtpvp8depay ! vp8dec ! autovideosink
  39
  40     # send
  41     gst-launch-1.0 -v ximagesrc ! videoconvert ! videoscale ! video/x-raw,format=I420,width=800,height=600,framerate=25/1 ! jpegenc ! rtpjpegpay ! udpsink host=239.255.12.42 port=5004
  42     # receive
  43     gst-launch-1.0 udpsrc address=239.255.12.42 port=5004 ! application/x-rtp,encoding-name=JPEG,payload=26 ! rtpjpegdepay ! jpegdec ! autovideosink
  44
  45
  46 * https://stackoverflow.com/questions/33747500/using-gstreamer-to-capture-screen-and-show-it-in-a-window/33822024#33822024
  47 * http://www.einarsundgren.se/gstreamer-basic-real-time-streaming-tutorial/
  48 * https://gist.github.com/tetkuz/0c038321d05586841897
  49 * https://gist.github.com/esrever10/7d39fe2d4163c5b2d7006495c3c911bb
  50 * https://gist.github.com/nebgnahz/26a60cd28f671a8b7f522e80e75a9aa5
  51 * https://salsa.debian.org/debconf-video-team/ansible/-/blob/master/roles/voctomix/templates/videoteam-stream.j2
  52 * https://github.com/xfxf/video-scripts/blob/master/michael/youtube-live.sh
  53   (and others in the same repo)
  54
  55 # VLC
  56 Note that you have to close VLC and open it again for new streaming as VLC leaves the connections
  57 open (I spent hours figuring out why http based streaming doesn't work - `netstat -4 --ip` is nice
  58 for debugging in that respect).
  59
  60 ## RTP
  61 ### Source
  62 The address has to be the address where the video should be streamed **to**. In the following
  63 examples, a multicast address is used. It is either the IP address of the device receiving the video (unicast address) or a multicast address
  64 like 239.255.12.42 (multicast addresses are between 224.0.0.0 and 239.255.255.255, some of
  65 them being reserved, 239.0.0.0 to 239.255.255.255 are Organization-Local Scope so they are
  66 good candidates, see
  67 https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml).
  68
  69     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
  70     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
  71     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
  72     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
  73
  74 ### Player
  75     cvlc rtp://239.255.12.42
  76
  77
  78 ## RTSP
  79 For VLC, RTSP means RTSP combined with RTP.
  80
  81 ### Source
  82 We assume that the video source computer has the external IP 192.168.1.54.
  83 Instead of rtsp://192.168.1.54:8554/ we could also use rtsp://192.168.1.54:8554/mystream.sdp
  84
  85     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
  86     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
  87
  88
  89 ### Player
  90 The address needs to be the address of the source. Note the backslash at the end.
  91
  92     vlc rtsp://192.168.1.54:8554/
  93
  94
  95 ## VLC Remarks
  96 * Latency: The following options are said to reduce latency:
  97
  98       --network-caching=150 --clock-jitter=0 --clock-synchro=0
  99
 100 * Duplicating a stream is nice for debugging:
 101
 102       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
 103       cvlc rtp://239.255.12.42
 104
 105
 106 ## HTTP
 107 The address at the source side has to be the external one of the local computer.
 108
 109 ### Source (server)
 110     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
 111
 112 ### Player (client)
 113
 114     vlc http://192.168.1.54:8080
 115
 116
 117 # Kodi
 118 The player built into code knows at least the following streaming protocols: http, rtsp.
 119
 120 https://kodi.wiki/index.php?title=Internet_video_and_audio_streams