Add script to decode JSON SDP.
[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 ## 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