Repeatable crashes on local streaming

[lokari]

Hi,

since updating to 2.2.1 i see constant crashes on some special local streams. These streams come from an VDR TV server and only occur on some channels the send out their TV program in 720p.

Here's what the crash reporter tells: http://pastebin.com/raw.php?i=nQRyXG5P

Funny thing is that this only seems to happen when starting VLC and handing it the Playlist as a URL to the local server. Whenever i just start it opening the downloaded playlist from the hard disk nothing happens. Also other tv stations work totally fine - even the higher resolution ones.

Here's how i launch VLC using Alfred.app (Application launcher and the reason why you see Alfred in the crash log):

Code: Select all

/Applications/VLC.app/Contents/MacOS/VLC http://192.168.88.200:3000/channels.m3u

before that some WakeOnLAN-Action is happening which basically works fine including loading of the playlist. The crash then happens after watching one of the problematic TV channels for about 20 seconds. If i switch around and back to these channels they sometime keep working and VLC don't crash but i couldn't find a way yet to reliable get to that point.

Any idea?

Thanks!

[lokari]

Oh, i just discovered the nightly version and it looks to be fixed in the latest nightly from yesterday (2.2.2 Weatherwax). I'll check some more and report if the problem comes back.

[fkuehne]

Cool, thanks!

[fkuehne]

@sharonholmes: please post this in a separate thread on the linux forum. Thanks!

[lokari]

@felix Ok, tried some more and couldn't reproduce the problem so consider it fixed. Thanks btw. for your great work.

[fkuehne]

Nice, thanks a lot for the follow-up!

[lokari]

Hmpf - probably shouldn't have said that. Now after some tries it happened again :-/ though i can't easily reproduce it now. It works after restarting VLC with the same stream. I've sent in an error report containing a link to this thread as relation.

[lokari]

@felix can i be of any more help regarding this problem? I'd like to help fixing it.

[lokari]

@felix any news on that topic? I still keep getting this crashes. Nearly unable to watch some of the streams. Here's an uptodate crash log: http://pastebin.com/raw.php?i=ye0HNf0a

[lokari]

Just wanted to leave a note that the problem still occurs after the lastest update to Version 2.2.2 today.

[dfuhrmann]

Hi,

This should be fixed for VLC 3.0, and I just pushed another patch which should fix this issue for 2.2.3. It would be cool if you can test both nightly builds (the 3.0 build, and a 2.2 build from tommorow (or later)).

[lokari]

sorry, I'm a bit late. It looked like it first worked on 3.0.0-nightly but then it crashed again. With the latest nightly from 3.0 it also crashes quite quickly in the same situations.

Here's the crashdump from today: http://pastebin.com/raw/Hp7iiPkn

I'll give the 2.2.0-nightly another chance and report back.

[lokari]

Ok looks like the behaviour differs now but the problem still isn't gone.

Here's the 2.2.0-nightly crashlog http://pastebin.com/raw/KtfksckS

It worked on first start, after switching channels the first time the problem reoccured, it stopped the stream but didn't crash first. Unfortunately it crashed again on the second try.

[dfuhrmann]

I think its hard to help you, then, without access to a test stream.

[lokari]

It's hard to hand out access as the stream is coming from a local VDR streamdev server. Any chance to dump the stream somehow to help you with that?

[ajmas]

BTW are you displaying subtitles when this happens?

[lokari]

No subtitles at all. There are some within the stream from time to time (actually it's TV programm so depends on the broadcaster).

[lokari]

I'm not sure how clear my opening post was so I try to elaborate a bit more.

I'm streaming TV from a local VDR server. This basically works well on all channels with the only exception of channels from the german public television (ARD, ZDF and all of its regional and digital sub channels). These are the only ones among the ones I receive which are broadcasting there video signal in 720p50. Mostly all other channels that I usualy waatch broadcast 1080i25. Stream bitrate is around 12-15 MBit/s according to the info panel. That's about the maximum I get. I do get quite a bit less data on other channels (like Sky Germany Pay-TV on 1080i25 channels, private German TV like RTL, Pro7 and others with also 1080i25).

May the stream bandwith be the problem? I don't see any high error rate but you never know.

Also what came to my eyes while watching the Codec panel is the fact that EPG data on this problematic channels is quite huge. Other channels don't have that big pack of EPG data in the stream. I think public television publishes about 2-3 weeks ahead.

At the end the funny thing is that it sometimes works while it fails very often.

Hope I could provide some additional ideas.

Thanks,
Frank

[dfuhrmann]

I suspect that we have some problem with parsing the metadata from the stream. And then, this invalid data is tried to be displayed in the UI and crashes the program.

[lokari]

Ok, sounds reasonable. Is there anything I can help you with fixing that problem?

[lokari]

I just wanted to let you know that this problem still exists in 2.2.3 even though it seems to occur not every time but still very often.

Let me know if there's anything I can help with (except coding unfortunately)

[ajmas]

What are the contents of the channels.m3u?

Depending on the actual stream format, maybe there could be a way to record the raw stream, that then could be analysed. @dfuhrmann do you have any suggestions?

[lokari]

The channels.m3u looks like this: http://pastebin.com/raw/4ETp9PUt

This is only a cut-out. The whole file is 4800 lines long currently (depends on the received TV stations on the DVB-S server, the channel file is fetched by a script on the beginning of a watching session).

I could try to record a MPEG2-TS dump of a channel that causes these problems. I'm unsure if I could dump it from the streamdev server that generates the Channel URLs found in the channels.m3u but i will try.

[lokari]

Ok,

I managed to get some interesting results.

First one of the normally crashing stations didn't crash repeatedly. I've dumped the stream while it didn't crash.

This was station

Code: Select all

#EXTINF:-1,1 Das Erste HD http://192.168.88.200:3000/S19.2E-1-1019-10301

from the channels.m3u, here's the dump: https://dl.dropboxusercontent.com/u/114 ... p-ok.ts.gz

After switching to

Code: Select all

#EXTINF:-1,3 BR Süd HD http://192.168.88.200:3000/S19.2E-1-1025-10325

which is also among the stations that frequently crash it did so after some seconds. Here's the dump for that - the crash came near to the end of the dump: https://dl.dropboxusercontent.com/u/114 ... rash.ts.gz

Crash report: http://pastebin.com/raw/HRMzmQSH

Hopefully this is something you can work with.

Frank

[centralplexus]

Same issue here. I'm using VLC for local streaming from a AVM DVB-C device (now the second model) and as soon as i switch to a HD channel, VLC will crash after a few seconds (5-30 sec).
Even if i start the m3u playlist with a HD as the first channel, chances are very high that VLC will crash if i'm not quick enough and switch to a SD channel.

This has been happening since VLC 2.2.1 - v2.2.2 didn't change things.

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY