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 ## gstreamer webrtc, another example
  68
  69 * blog post: https://aweirdimagination.net/2020/07/05/gstreamer-webrtc/
  70 * code: https://git.aweirdimagination.net/perelman/minimal-webrtc-gstreamer
  71
  72 ## websockets
  73
  74 connecting to websockets (plus gstreamer and v4l2sink)
  75
  76 https://michael.stapelberg.ch/posts/2020-06-06-iphone-camera-linux-v4l2loopback/
  77
  78         # send
  79         laplace / chromium
  80
  81         # receive
  82         websocat --insecure "wss://localhost:8080/ws_connect?id=cranky_kind_chipmunk"
  83
  84 ## more v4l2loopback/v4l2sink
  85
  86         # send
  87         gst-launch-1.0 videotestsrc ! v4l2sink device=/dev/video42
  88
  89         # receive
  90         cvlc v4l2:///dev/video42
  91
  92 ## SRT and gstreamer
  93
  94 * https://github.com/Haivision/srt/blob/master/docs/gstreamer.md
  95 * https://srtlab.github.io/srt-cookbook/
  96
  97 # VLC
  98 Note that you have to close VLC and open it again for new streaming as VLC leaves the connections
  99 open (I spent hours figuring out why http based streaming doesn't work - `netstat -4 --ip` is nice
 100 for debugging in that respect).
 101
 102 ## RTP
 103 ### Source
 104 The address has to be the address where the video should be streamed **to**. In the following
 105 examples, a multicast address is used. It is either the IP address of the device receiving the video (unicast address) or a multicast address
 106 like 239.255.12.42 (multicast addresses are between 224.0.0.0 and 239.255.255.255, some of
 107 them being reserved, 239.0.0.0 to 239.255.255.255 are Organization-Local Scope so they are
 108 good candidates, see
 109 https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml).
 110
 111     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
 112     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
 113     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
 114     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
 115
 116 ### Player
 117     cvlc rtp://239.255.12.42
 118
 119
 120 ## RTSP
 121 For VLC, RTSP means RTSP combined with RTP.
 122
 123 ### Source
 124 We assume that the video source computer has the external IP 192.168.1.54.
 125 Instead of rtsp://192.168.1.54:8554/ we could also use rtsp://192.168.1.54:8554/mystream.sdp
 126
 127     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
 128     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
 129
 130
 131 ### Player
 132 The address needs to be the address of the source. Note the backslash at the end.
 133
 134     vlc rtsp://192.168.1.54:8554/
 135
 136
 137 ## VLC Remarks
 138 * Latency: The following options are said to reduce latency:
 139
 140       --network-caching=150 --clock-jitter=0 --clock-synchro=0
 141
 142 * Duplicating a stream is nice for debugging:
 143
 144       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
 145       cvlc rtp://239.255.12.42
 146
 147
 148 ## HTTP
 149 The address at the source side has to be the external one of the local computer.
 150
 151 ### Source (server)
 152     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
 153
 154 ### Player (client)
 155
 156     vlc http://192.168.1.54:8080
 157
 158
 159 # Kodi
 160 The player built into code knows at least the following streaming protocols: http, rtsp.
 161
 162 https://kodi.wiki/index.php?title=Internet_video_and_audio_streams