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 ## WebRTC signaling
  14
  15 * https://developer.mozilla.org/en-US/docs/Web/API/WebRTC_API/Signaling_and_video_calling
  16 * https://www.tutorialspoint.com/webrtc/webrtc_signaling.htm
  17 * https://www.html5rocks.com/en/tutorials/webrtc/infrastructure/
  18 * https://github.com/topics/webrtc-signaling
  19
  20 # gstreamer
  21 * Supports RTP
  22 * Supports webcam capture via v4l (video for linux)
  23 * Supports screen capture via xmanager/ximagesrc
  24 * Interesting URLs:
  25   * WebRTC in one direction only: https://stackoverflow.com/questions/57430215/how-to-use-webrtcbin-create-offer-only-receive-video
  26   * gstreamer to VLC via RTP: https://stackoverflow.com/questions/13154983/gstreamer-rtp-stream-to-vlc
  27   * https://github.com/intel/gstreamer-media-SDK/issues/138
  28   * https://developer.ridgerun.com/wiki/index.php?title=GstWebRTC_Pipelines
  29   * https://developer.ridgerun.com/wiki/index.php?title=GstWebRTC_-_H264-Opus_Examples#Receive_Pipeline
  30
  31 ## WebRTC
  32 gstreamer has a WebRTC implementation.
  33 The examples at https://github.com/centricular/gstwebrtc-demos.git work once
  34
  35     export OPENSSL_CONF=''
  36
  37 has been set (see https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/issues/811)
  38
  39 ## gstreamer examples
  40     gst-launch-1.0 -v playbin uri=file:///home/philipp/tmp/GerisGame.mp4
  41
  42     # send
  43     gst-launch-1.0 ximagesrc ! videoconvert ! videoscale ! video/x-raw,width=800,height=600 ! vp8enc ! rtpvp8pay ! udpsink host=239.255.12.42 port=5004
  44     # receive
  45     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
  46
  47     # send
  48     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
  49     # receive
  50     gst-launch-1.0 udpsrc address=239.255.12.42 port=5004 ! application/x-rtp,encoding-name=JPEG,payload=26 ! rtpjpegdepay ! jpegdec ! autovideosink
  51
  52
  53 * https://stackoverflow.com/questions/33747500/using-gstreamer-to-capture-screen-and-show-it-in-a-window/33822024#33822024
  54 * http://www.einarsundgren.se/gstreamer-basic-real-time-streaming-tutorial/
  55 * https://gist.github.com/tetkuz/0c038321d05586841897
  56 * https://gist.github.com/esrever10/7d39fe2d4163c5b2d7006495c3c911bb
  57 * https://gist.github.com/nebgnahz/26a60cd28f671a8b7f522e80e75a9aa5
  58 * https://salsa.debian.org/debconf-video-team/ansible/-/blob/master/roles/voctomix/templates/videoteam-stream.j2
  59 * https://github.com/xfxf/video-scripts/blob/master/michael/youtube-live.sh
  60   (and others in the same repo)
  61
  62 ## websockets
  63
  64 connecting to websockets (plus gstreamer and v4l2sink)
  65
  66 https://michael.stapelberg.ch/posts/2020-06-06-iphone-camera-linux-v4l2loopback/
  67
  68         # send
  69         laplace / chromium
  70
  71         # receive
  72         websocat --insecure "wss://localhost:8080/ws_connect?id=cranky_kind_chipmunk"
  73
  74 ## more v4l2loopback/v4l2sink
  75
  76         # send
  77         gst-launch-1.0 videotestsrc ! v4l2sink device=/dev/video42
  78
  79         # receive
  80         cvlc v4l2:///dev/video42
  81
  82 # VLC
  83 Note that you have to close VLC and open it again for new streaming as VLC leaves the connections
  84 open (I spent hours figuring out why http based streaming doesn't work - `netstat -4 --ip` is nice
  85 for debugging in that respect).
  86
  87 ## RTP
  88 ### Source
  89 The address has to be the address where the video should be streamed **to**. In the following
  90 examples, a multicast address is used. It is either the IP address of the device receiving the video (unicast address) or a multicast address
  91 like 239.255.12.42 (multicast addresses are between 224.0.0.0 and 239.255.255.255, some of
  92 them being reserved, 239.0.0.0 to 239.255.255.255 are Organization-Local Scope so they are
  93 good candidates, see
  94 https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml).
  95
  96     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
  97     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
  98     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
  99     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
 100
 101 ### Player
 102     cvlc rtp://239.255.12.42
 103
 104
 105 ## RTSP
 106 For VLC, RTSP means RTSP combined with RTP.
 107
 108 ### Source
 109 We assume that the video source computer has the external IP 192.168.1.54.
 110 Instead of rtsp://192.168.1.54:8554/ we could also use rtsp://192.168.1.54:8554/mystream.sdp
 111
 112     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
 113     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
 114
 115
 116 ### Player
 117 The address needs to be the address of the source. Note the backslash at the end.
 118
 119     vlc rtsp://192.168.1.54:8554/
 120
 121
 122 ## VLC Remarks
 123 * Latency: The following options are said to reduce latency:
 124
 125       --network-caching=150 --clock-jitter=0 --clock-synchro=0
 126
 127 * Duplicating a stream is nice for debugging:
 128
 129       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
 130       cvlc rtp://239.255.12.42
 131
 132
 133 ## HTTP
 134 The address at the source side has to be the external one of the local computer.
 135
 136 ### Source (server)
 137     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
 138
 139 ### Player (client)
 140
 141     vlc http://192.168.1.54:8080
 142
 143
 144 # Kodi
 145 The player built into code knows at least the following streaming protocols: http, rtsp.
 146
 147 https://kodi.wiki/index.php?title=Internet_video_and_audio_streams