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 ## websockets
  56
  57 connecting to websockets (plus gstreamer and v4l2sink)
  58
  59 https://michael.stapelberg.ch/posts/2020-06-06-iphone-camera-linux-v4l2loopback/
  60
  61         # send
  62         laplace / chromium
  63
  64         # receive
  65         websocat --insecure "wss://localhost:8080/ws_connect?id=cranky_kind_chipmunk"
  66
  67 ## more v4l2loopback/v4l2sink
  68
  69         # send
  70         gst-launch-1.0 videotestsrc ! v4l2sink device=/dev/video42
  71
  72         # receive
  73         cvlc v4l2:///dev/video42
  74
  75 # VLC
  76 Note that you have to close VLC and open it again for new streaming as VLC leaves the connections
  77 open (I spent hours figuring out why http based streaming doesn't work - `netstat -4 --ip` is nice
  78 for debugging in that respect).
  79
  80 ## RTP
  81 ### Source
  82 The address has to be the address where the video should be streamed **to**. In the following
  83 examples, a multicast address is used. It is either the IP address of the device receiving the video (unicast address) or a multicast address
  84 like 239.255.12.42 (multicast addresses are between 224.0.0.0 and 239.255.255.255, some of
  85 them being reserved, 239.0.0.0 to 239.255.255.255 are Organization-Local Scope so they are
  86 good candidates, see
  87 https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml).
  88
  89     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
  90     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
  91     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
  92     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
  93
  94 ### Player
  95     cvlc rtp://239.255.12.42
  96
  97
  98 ## RTSP
  99 For VLC, RTSP means RTSP combined with RTP.
 100
 101 ### Source
 102 We assume that the video source computer has the external IP 192.168.1.54.
 103 Instead of rtsp://192.168.1.54:8554/ we could also use rtsp://192.168.1.54:8554/mystream.sdp
 104
 105     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
 106     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
 107
 108
 109 ### Player
 110 The address needs to be the address of the source. Note the backslash at the end.
 111
 112     vlc rtsp://192.168.1.54:8554/
 113
 114
 115 ## VLC Remarks
 116 * Latency: The following options are said to reduce latency:
 117
 118       --network-caching=150 --clock-jitter=0 --clock-synchro=0
 119
 120 * Duplicating a stream is nice for debugging:
 121
 122       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
 123       cvlc rtp://239.255.12.42
 124
 125
 126 ## HTTP
 127 The address at the source side has to be the external one of the local computer.
 128
 129 ### Source (server)
 130     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
 131
 132 ### Player (client)
 133
 134     vlc http://192.168.1.54:8080
 135
 136
 137 # Kodi
 138 The player built into code knows at least the following streaming protocols: http, rtsp.
 139
 140 https://kodi.wiki/index.php?title=Internet_video_and_audio_streams