[Live-devel] RTSP Seek problems

[Philippe Bridant]

Hello,

My name is Philippe Bridant. I am working on a compagny named "SmartJog"
which is specialized into professional broadcast of digital video files
over satellite
and terrestrial VPN.

I am in charge of contributing to the VLC livedotcom plugin to make it
working.
I met the VLC devel team which advised me to take contact with you if I had
questions about the live.com implementation into VLC.

I will have only a few question to ask you...

I have been testing the current livedotcom plugin for one week and my tests
have shown some problems with the "seek" feature.

When seeking, (so after a PLAY command), it seems that the RTSPClient class
continues to provide the rest of the "deprecated" buffers it had
collected before
the (seek) PLAY command to the livedotcom plugin demuxer.

It seems to generate audio and video synchronisation problems with VLC
core...

Here is the VLC debug output:

====================================================

## PERFECT VIDEO AND AUDIO PLAYOUT

## SEEK ACTION DONE HERE

Sending request: PLAY rtsp://jpetazzo:5544/test6.mp4/trackID=65736 RTSP/1.0
CSeq: 8
Session: 3414775516466992135
Range: npt=2.263-
User-Agent: VLC Media Player (LIVE.COM Streaming Media v2004.12.15)


Received PLAY response: RTSP/1.0 200 OK
Server: DSS/5.0.1.1 (Build/464.1.1; Platform/Linux; Release/5; )
Cseq: 8
Session: 3414775516466992135
Range: npt=2.26300-25.44000
RTP-Info:
url=trackID=65736;seq=13523;rtptime=869036513,url=trackID=65636;seq=36283;rtptime=775610578 




Sending request: PLAY rtsp://jpetazzo:5544/test6.mp4/trackID=65636 RTSP/1.0
CSeq: 9
Session: 3414775516466992135
Range: npt=2.263-
User-Agent: VLC Media Player (LIVE.COM Streaming Media v2004.12.15)


Received PLAY response: RTSP/1.0 200 OK
Server: DSS/5.0.1.1 (Build/464.1.1; Platform/Linux; Release/5; )
Cseq: 9
Session: 3414775516466992135
Range: npt=2.26300-25.44000
RTP-Info:
url=trackID=65736;seq=15634;rtptime=869036513,url=trackID=65636;seq=36545;rtptime=775610578 




## FROM HERE, PLAYING OLD BUFFERS ==> VIDEO AND AUDIO PROBLEMS

[00000441] main audio output warning: PTS is out of range (18144844),
dropping buffer
[00000441] main audio output warning: PTS is out of range (18123777),
dropping buffer
[00000441] main audio output warning: PTS is out of range (18102708),
dropping buffer
[00000441] main audio output warning: PTS is out of range (18081622),
dropping buffer
[00000441] main audio output warning: PTS is out of range (18060534),
dropping buffer
[00000441] main audio output warning: PTS is out of range (17555903),
dropping buffer
[00000441] main audio output warning: PTS is out of range (17534825),
dropping buffer
[00000441] main audio output warning: PTS is out of range (17513744),
dropping buffer
[00000441] main audio output warning: PTS is out of range (17492656),
dropping buffer
[00000441] main audio output warning: PTS is out of range (17471570),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16981706),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16960621),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16939534),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16918446),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16897370),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16421912),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16400830),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16379741),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16358665),
dropping buffer
[00000441] main audio output warning: PTS is out of range (16337581),
dropping buffer
[00000439] main video output warning: late picture skipped (21250503)
[00000439] main video output warning: late picture skipped (20649637)
[00000439] main video output warning: late picture skipped (20094842)
[00000439] main video output warning: late picture skipped (19523661)
[00000439] main video output warning: late picture skipped (18966735)
...
...
...
...
...
...

## FROM HERE, SYNCHRO IS BACK, PLAYOUT IS GOOD.

============================================================

My questions are:
- Does the live lib do really continue to send old buffers to the demuxer ?
- If yes, is there a way to flush them so we have directly directly the
brand new RTP packets ?

- Is there a LIVE.COM tutorial for developpers ?
- Is there any implementation of LIVE.COM wich supports seek feature
over RTSP/RTP streaming ?

Thanks a lot,

Best regards

Philippe Bridant