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 There's a new recvonly example:
  40
  41 * https://github.com/centricular/gstwebrtc-demos/commit/000cfb6cd817ca0f07d761795b352a8b8b9074f8
  42 * `sendonly/webrtc-recvonly-h264.c`
  43
  44 ## gstreamer examples
  45     gst-launch-1.0 -v playbin uri=file:///home/philipp/tmp/GerisGame.mp4
  46
  47     # send
  48     gst-launch-1.0 ximagesrc ! videoconvert ! videoscale ! video/x-raw,width=800,height=600 ! vp8enc ! rtpvp8pay ! udpsink host=239.255.12.42 port=5004
  49     # receive
  50     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
  51
  52     # send
  53     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
  54     # receive
  55     gst-launch-1.0 udpsrc address=239.255.12.42 port=5004 ! application/x-rtp,encoding-name=JPEG,payload=26 ! rtpjpegdepay ! jpegdec ! autovideosink
  56
  57
  58 * https://stackoverflow.com/questions/33747500/using-gstreamer-to-capture-screen-and-show-it-in-a-window/33822024#33822024
  59 * http://www.einarsundgren.se/gstreamer-basic-real-time-streaming-tutorial/
  60 * https://gist.github.com/tetkuz/0c038321d05586841897
  61 * https://gist.github.com/esrever10/7d39fe2d4163c5b2d7006495c3c911bb
  62 * https://gist.github.com/nebgnahz/26a60cd28f671a8b7f522e80e75a9aa5
  63 * https://salsa.debian.org/debconf-video-team/ansible/-/blob/master/roles/voctomix/templates/videoteam-stream.j2
  64 * https://github.com/xfxf/video-scripts/blob/master/michael/youtube-live.sh
  65   (and others in the same repo)
  66
  67 ## websockets
  68
  69 connecting to websockets (plus gstreamer and v4l2sink)
  70
  71 https://michael.stapelberg.ch/posts/2020-06-06-iphone-camera-linux-v4l2loopback/
  72
  73         # send
  74         laplace / chromium
  75
  76         # receive
  77         websocat --insecure "wss://localhost:8080/ws_connect?id=cranky_kind_chipmunk"
  78
  79 ## more v4l2loopback/v4l2sink
  80
  81         # send
  82         gst-launch-1.0 videotestsrc ! v4l2sink device=/dev/video42
  83
  84         # receive
  85         cvlc v4l2:///dev/video42
  86
  87 ## SRT and gstreamer
  88
  89 * https://github.com/Haivision/srt/blob/master/docs/gstreamer.md
  90 * https://srtlab.github.io/srt-cookbook/
  91
  92 # VLC
  93 Note that you have to close VLC and open it again for new streaming as VLC leaves the connections
  94 open (I spent hours figuring out why http based streaming doesn't work - `netstat -4 --ip` is nice
  95 for debugging in that respect).
  96
  97 ## RTP
  98 ### Source
  99 The address has to be the address where the video should be streamed **to**. In the following
 100 examples, a multicast address is used. It is either the IP address of the device receiving the video (unicast address) or a multicast address
 101 like 239.255.12.42 (multicast addresses are between 224.0.0.0 and 239.255.255.255, some of
 102 them being reserved, 239.0.0.0 to 239.255.255.255 are Organization-Local Scope so they are
 103 good candidates, see
 104 https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml).
 105
 106     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
 107     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
 108     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
 109     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
 110
 111 ### Player
 112     cvlc rtp://239.255.12.42
 113
 114
 115 ## RTSP
 116 For VLC, RTSP means RTSP combined with RTP.
 117
 118 ### Source
 119 We assume that the video source computer has the external IP 192.168.1.54.
 120 Instead of rtsp://192.168.1.54:8554/ we could also use rtsp://192.168.1.54:8554/mystream.sdp
 121
 122     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
 123     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
 124
 125
 126 ### Player
 127 The address needs to be the address of the source. Note the backslash at the end.
 128
 129     vlc rtsp://192.168.1.54:8554/
 130
 131
 132 ## VLC Remarks
 133 * Latency: The following options are said to reduce latency:
 134
 135       --network-caching=150 --clock-jitter=0 --clock-synchro=0
 136
 137 * Duplicating a stream is nice for debugging:
 138
 139       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
 140       cvlc rtp://239.255.12.42
 141
 142
 143 ## HTTP
 144 The address at the source side has to be the external one of the local computer.
 145
 146 ### Source (server)
 147     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
 148
 149 ### Player (client)
 150
 151     vlc http://192.168.1.54:8080
 152
 153
 154 # Kodi
 155 The player built into code knows at least the following streaming protocols: http, rtsp.
 156
 157 https://kodi.wiki/index.php?title=Internet_video_and_audio_streams