The VideoLAN Forums

Hi.

The latest versions of VLC (1.0.3 and higher) produce some strange RTSP playback artifacts - the video has small loops in playback, when the data is not coming fast enough. There is nothing in logs, even on maximal verbosity.

I checked the previous version (1.0.0-pre) and the stream playback there was stable. There are brief pauses if there is delay in video, but no visible loops.

Is there any setting that can help to resolve this issue? Also, were there any significant changes to RTSP code, which might have caused such issue?

Thanks!

Some sample URL you could share to us?

I sent you a PM with a sample URL.

Thanks.

With VLC 1.0.5 I get and similar complains to log.

With VLC 1.1.0 nigthlies I also get which would indicate decoding problems.

Hi.

This probably because of UDP video loss, can you please try with "RTSP over TCP" enabled in RTSP demuxer settings?
When I enable it, the decoding goes fine, except these loops.

By the way, following your comment I tried to uncheck the "drop late frames" setting, but it still didn't help.
Was there any significant decoder updates done lately, which might have caused this?

Also, I tried the stream in QT, seems to work fine.

Thanks again.

Was there any significant decoder updates done lately, which might have caused this?

libavcodec is changing all the time, but I don't think the problem is there, since if I record the stream and playback it, it plays just fine in VLC and in QuickTime.

Hi.

So maybe it's in vlc rtsp access filter?

What happens if you play it with RTSP over TCP enforced, do you have any error messages or loops?

Regards.

Loops are there with TCP. It is possible that you could try with different video encoder? (that way we could limit the reason)

Hi.

Loops are there with TCP.

I see, same as here.

It is possible that you could try with different video encoder? (that way we could limit the reason)

Unfortunately this encoder is part of the source firmware, so there is no way to change it.
I did reproduce same micro-loops with FFMPEG/DSS as well - just much harder to catch and demonstrate them, as they happen in low bandwidth conditions.

For locating the reason on VLC side, you can just any version below 1.0.0 - like 0.9.9:
http://download.videolan.org/pub/videol ... -win32.exe

It will play the video fine, there will be some pauses - but no micro-loops.

Thanks again.

Hi.

I tracked the issue some more, and noticed that it happens only in first 30 seconds or so of the video.
Once they passed, the stream is stable and works normally.
Is there anything related that can be tuned?

Also, can the problem be in contribs and not in VLC itself? Maybe the live555 demuxer was updated?


I actually tried to locate the change that caused the issue via git-bisect, but got stumbled on contrib compatibility. How can I locate a contrib that was compatible to 1.0.0 pre versions?

Thanks again.

Is there anything related that can be tuned?

Caching is about the only option that has some time values that could be related to this.

Maybe the live555 demuxer was updated?

Live555 has been updated many times AFAIK.

How can I locate a contrib that was compatible to 1.0.0 pre versions?

I would guess j-b should know what was used.

Hi.

I tried today the latest 1.1, and noticed that the jumps have gone .

Any idea if Live 555 was updated, or it was something else?

Regards.

live555 was updated.

Thanks for the update, this must be it.

Cool.

I was happy too early - a new issue has appeared:

viewtopic.php?f=14&t=79032