add link to "new" gst webrtc recvonly example
[toast/stream2beamer.git] / 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 # VLC
88 Note that you have to close VLC and open it again for new streaming as VLC leaves the connections
89 open (I spent hours figuring out why http based streaming doesn't work - `netstat -4 --ip` is nice
90 for debugging in that respect).
91
92 ## RTP
93 ### Source
94 The address has to be the address where the video should be streamed **to**. In the following
95 examples, a multicast address is used. It is either the IP address of the device receiving the video (unicast address) or a multicast address 
96 like 239.255.12.42 (multicast addresses are between 224.0.0.0 and 239.255.255.255, some of
97 them being reserved, 239.0.0.0 to 239.255.255.255 are Organization-Local Scope so they are
98 good candidates, see
99 https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml).
100
101     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
102     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
103     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
104     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
105
106 ### Player
107     cvlc rtp://239.255.12.42
108
109
110 ## RTSP
111 For VLC, RTSP means RTSP combined with RTP.
112
113 ### Source
114 We assume that the video source computer has the external IP 192.168.1.54.
115 Instead of rtsp://192.168.1.54:8554/ we could also use rtsp://192.168.1.54:8554/mystream.sdp
116
117     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
118     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
119
120
121 ### Player
122 The address needs to be the address of the source. Note the backslash at the end.
123
124     vlc rtsp://192.168.1.54:8554/
125
126
127 ## VLC Remarks
128 * Latency: The following options are said to reduce latency:
129
130       --network-caching=150 --clock-jitter=0 --clock-synchro=0
131
132 * Duplicating a stream is nice for debugging:
133
134       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
135       cvlc rtp://239.255.12.42
136
137
138 ## HTTP
139 The address at the source side has to be the external one of the local computer.
140
141 ### Source (server)
142     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
143
144 ### Player (client)
145
146     vlc http://192.168.1.54:8080
147
148
149 # Kodi
150 The player built into code knows at least the following streaming protocols: http, rtsp.
151
152 https://kodi.wiki/index.php?title=Internet_video_and_audio_streams