SDP - trouble using control to isolate audio/video

[tmedina]

I'm streaming audio/video from an IP camera through VLC as the client. I have no documentation on the camera. I need to use rtsp to stream the audio and video channels separately, but I can't seem to get it to work here. On other cameras I've been able to use something like rtsp://ip:port/control, but it's not working for me here. Below is the sdp message:

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Sending request: DESCRIBE rtsp://192.168.1.123/mpeg4 RTSP/1.0 CSeq: 3 User-Agent: LibVLC/2.0.5 (LIVE555 Streaming Media v2012.09.13) Accept: application/sdp Received 1308 new bytes of response data. Received a complete DESCRIBE response: RTSP/1.0 200 OK CSeq: 3 Date: Sun, Jan 02 2000 23:48:34 GMT Content-Base: rtsp://192.168.1.123/mpeg4/ Content-Type: application/sdp Content-Length: 1147 v=0 o=- 946855189887438 1 IN IP4 192.168.1.123 s=RTSP/RTP stream from Network Video Server i=mpeg4 t=0 0 a=tool:LIVE555 Streaming Media v2009.09.28 a=type:broadcast a=control:* a=range:npt=0- a=x-qt-text-nam:RTSP/RTP stream from Network Video Server a=x-qt-text-inf:mpeg4 m=video 0 RTP/AVP 96 c=IN IP4 0.0.0.0 b=AS:2500 a=rtpmap:96 H264/90000 a=fmtp:96 packetization-mode=1;profile-level-id=640028;sprop-parameter-sets=Z2QAKK2EBUViuKxUdCAqKxXFYqOhAVFYrisVHQgKisVxWKjoQFRWK4rFR0ICorFcVio6ECSFITk8nyfk/k/J8nm5s00IEkKQnJ5Pk/J/J+T5PNzZprQCgDzSpAAAAwHgAABwgYEAAJiWAACrqW974XhEI1A=,aO48sA==;config=0000000167640028ad84054562b8ac5474202a2b15c562a3a1015158ae2b151d080a8ac57158a8e84054562b8ac5474202a2b15c562a3a10248521393c9f27e4fe4fc9f279b9b34d081242909c9e4f93f27f27e4f93cdcd9a6b402803cd2a400000301e00000708181000098960000aba96f7be1784423500000000168ee3cb0 a=x-dimensions: 1280, 960 a=x-framerate: 30 a=control:track1 m=audio 0 RTP/AVP 96 c=IN IP4 0.0.0.0 b=AS:256 a=rtpmap:96 MPEG4-GENERIC/16000/2 a=fmtp:96 streamtype=5;profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1408 a=control:track2

Here's what I've tried:

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rtsp://192.168.1.123/mpeg4 -- streams both a/v rtsp://192.168.1.123/track1 -- error, your input can't be opened rtsp://192.168.1.123/mpeg4/track1 -- error rtsp//192.168.1.123/mpeg4#track1 -- streams both a/v rtsp://192.168.1.123/foobar/mpeg4 -- streams both a/v rtsp://192.168.1.123/mpeg4/foobar -- error

In the VLC toolbar, I can select Video-->VideoTrack-->Disable, to turn off the video, but I need to be able to do this with the rtsp url. Not sure if there's some finer point of the url syntax that I'm missing, but perusing the RFC's hasn't really helped so far.

Thanks!

[tmedina]

Since the camera uses a Live555 server, I posted this question to the Live555 mail list as well. I'm sharing Ross's answer here in case anyone else is interested:

As a RTSP client, you can ask to stream just a single track, but *not* by specifying the track in the URL that you give to the RTSP "DESCRIBE" command. (That URL must be one that represents the entire stream - i.e., in your example: "rtsp://192.168.1.123/mpeg4" )

Instead, the way you specify which track(s) you want is in the URL that you give to the RTSP "SETUP" command. (The RTSP client will issue one "SETUP" command for each track that it wants.) The RTSP "SETUP" command will use an URL that specifies each track that you want - i.e., in your example: "rtsp://192.168.1.123/mpeg4/track1"

This will be done automatically by your RTSP client application, if (and only if) it allows you to choose which track(s) you want. Our "openRTSP" application does this (using the "-a" and/or "-v" options). VLC (although it's not our application) apparently does as well, as you noted.


In the VLC toolbar, I can select Video-->VideoTrack-->Disable, to turn off the video, but I need to be able to do this with the rtsp url.

As I noted above, you can't do that.

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/

FWIW, some other RTSP servers I've used do allow track separation through the DESCRIBE, but if this is how Live555 works, then I'll just work with it as outlined above.

[Sébastien Escudier]

You can also use the command line option --no-audio or --no-video