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[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 ## 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