Problems in implementing responce for RTSP's SETUP request

Question

I'm implementing simple RTSP server that should stream mjpeg over rtsp. The first problem I faced was the "hanging" RTSP client (i tried vlc and openRTSP) when I respond with some response data: buffering issue with java communicating vlc

However, that was easy to find out that the root of the problem was missed double \r\n sequence at the end of the request. I have successfully coded responses for OPTIONS and DESCRIBE, that are correctly handled on the client.

I faced with the problem when tried to implement SETUP. When I output some correctly formatted RTSP response to SETUP, both openRTSPvlc doesn't handle the response as complete:

openRTSP rtsp://localhost:6666/autostream.mjpg
Opening connection to 127.0.0.1, port 6666...
...remote connection opened
Sending request: OPTIONS rtsp://localhost:6666/autostream.mjpg RTSP/1.0
CSeq: 2
User-Agent: openRTSP (LIVE555 Streaming Media v2013.04.30)


Received 158 new bytes of response data.
Received a complete OPTIONS response:
RTSP/1.0 200 OK
CSeq: 2
Public: OPTIONS, PAUSE, PLAY, SETUP, SET_PARAMETER, TEARDOWN
Server: GStreamer RTSP server
Date: Tue, 10 Sep 2013 19:56:53 GMT


Sending request: DESCRIBE rtsp://localhost:6666/autostream.mjpg RTSP/1.0
CSeq: 3
User-Agent: openRTSP (LIVE555 Streaming Media v2013.04.30)
Accept: application/sdp


Received 484 new bytes of response data.
Received a complete DESCRIBE response:
RTSP/1.0 200 OK
CSeq: 3
Content-Type: application/sdp
Content-Base: rtsp://localhost:6666/autostream.mjpeg/
Server: GStreamer RTSP server
Date: Tue, 10 Sep 2013 19:56:53 GMT
Content-Length: 279

v=0
o=- 1188340656180883 1 IN IP4 127.0.0.1
s=Session streamed with GStreamer
i=rtsp-server
e=NONE
t=0 0
a=tool:GStreamer
a=type:broadcast
a=control:*
a=range:npt=0,000000-119,961667
m=video 0 RTP/AVP 96
c=IN IP4 127.0.0.1
a=rtpmap:96 JPEG/90000
a=control:stream=0

(plus 2 additional bytes)
Opened URL "rtsp://localhost:6666/autostream.mjpg", returning a SDP description:
v=0
o=- 1188340656180883 1 IN IP4 127.0.0.1
s=Session streamed with GStreamer
i=rtsp-server
e=NONE
t=0 0
a=tool:GStreamer
a=type:broadcast
a=control:*
a=range:npt=0,000000-119,961667
m=video 0 RTP/AVP 96
c=IN IP4 127.0.0.1
a=rtpmap:96 JPEG/90000
a=control:stream=0

Created receiver for "video/JPEG" subsession (client ports 57074-57075)
Sending request: SETUP rtsp://localhost:6666/autostream.mjpeg/stream=0 RTSP/1.0
CSeq: 4
User-Agent: openRTSP (LIVE555 Streaming Media v2013.04.30)
Transport: RTP/AVP;unicast;client_port=57074-57075


Received 215 new bytes of response data.

And nothing happens after that message. I assume, that something haappens with RTP and RTCP behind the scenes, but what is the way how debug it? VLC and openRTSP doesn't output detailed enough about it.

Any ideas?

Answer 1

As always, posting stupid questions to stackoverflow helps to find out the problem by myself (looks like a kind of Murphy law; I have to post it 3 hours ago to save my sleeping!)

The key word was

(plus 2 additional bytes)  

(openRTSP)

(plus 2 additional bytes)
[0x7f73900013f8] live555 demux debug: RTP subsession 'video/JPEG'

(vlc)

I have hardcoded the second /r/n in the response to DESCRIBE despite of having message body of that responcs. There should be double /r/n for those response that has empty body.