mythfrontend crashes when EPG changes (same as #613547)

[Tommi Nieminen]

Binary package hint: mythtv

This only happens in YLE (Finnish national broadcasting company) channels but on them without an exception. Every time the EPG data changes to mark the beginning of the next program, MythTV frontend crashes without even an error message, both when watching live TV or a recorded program. The bug has been previously reported by another person as #613547.

ProblemType: Crash
DistroRelease: Ubuntu 10.04
Package: mythtv-frontend 0.23.0+fixes24158-0ubuntu2
ProcVersionSignature: Ubuntu 2.6.32-24.42-generic 2.6.32.15+drm33.5
Uname: Linux 2.6.32-24-generic x86_64
Architecture: amd64
Date: Fri Sep 3 23:56:27 2010
ExecutablePath: /usr/bin/mythfrontend.real
InstallationMedia: Mythbuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100427.1)
Installed_mythplugins-dbg: 0.23.0+fixes24104-0ubuntu2
Installed_mythtv-dbg: 0.23.0+fixes24158-0ubuntu2
MythTVDirectoryPermissions:
 total 8
 drwxrwsr-x 2 mythtv mythtv 4096 2010-04-19 19:09 music
 drwxrwsr-x 2 mythtv mythtv 4096 2010-04-24 05:02 videos
ProcCmdline: /usr/bin/mythfrontend.real --logfile /tmp/mythfrontend.2722.log
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/usr/bin/zsh
SegvAnalysis:
 Segfault happened at: 0x7f992d85fd67 <_ZN15AvFormatDecoder8GetFrameE11DecodeTypes+30531>: mov %edx,0x5c(%rax)
 PC (0x7f992d85fd67) ok
 source "%edx" ok
 destination "0x5c(%rax)" (0x0000005c) not located in a known VMA region (needed writable region)!
SegvReason: writing NULL VMA
Signal: 11
SourcePackage: mythtv
StacktraceTop:
 AvFormatDecoder::GetFrame (this=0x42b29d0,
 NuppelVideoPlayer::GetFrameNormal (this=0x4265450,
 NuppelVideoPlayer::GetFrame (this=0x4265450,
 NuppelVideoPlayer::StartPlaying (this=0x4265450,
 SpawnDecode (param=0x4265450)
Title: mythfrontend.real crashed with SIGSEGV in AvFormatDecoder::GetFrame()
UserGroups: adm admin cdrom dialout lpadmin mythtv plugdev sambashare video
XsessionErrors: (polkit-gnome-authentication-agent-1:1284): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed

[Tommi Nieminen (tommi-nieminen)]

New information: A friend of mine who’s using VDR told me this phenomenon has been discussed in VDR’s forum some time ago; I couldn’t find it however. It seems the originator is not EPG in itself. At the beginning of each new program, YLE assigns language codes for all the audio and video channels. (Many programs have both Finnish and Swedish audio and subtitles, and additionally YLE uses “Dutch” for the hearing-impaired subtitles and for the visually-impaired audio channel.) This might be against the DVB spec or not, I don’t know.

[Apport retracing service (apport)]

StacktraceTop:
 AvFormatDecoder::GetFrame ()
 NuppelVideoPlayer::GetFrameNormal ()
 NuppelVideoPlayer::GetFrame ()
 NuppelVideoPlayer::StartPlaying ()
 ?? () from /usr/lib/libmythtv-0.23.so.0

[MarcRandolph (mrand)]

Howdy, and thank you for helping to improve Mythbuntu and mythtv by opening this ticket. I have forwarded this bug report upstream.

If you get a chance, it might turn out to be helpful to the developers if you coudl try to collect a short back-end log with --verbose important,general,eit during the time period when this event occurs.

[MarcRandolph (mrand)]

Apparently this part of the code has changed considerably after the 0.23 release, so this issue is unlikely to be addressed in 0.23, and so would need to be reproduced on 0.24 (which is still under heavy development). If you have the ability to try this on a test partition (or system), it would be greatly appreciated.

[Mario Limonciello (superm1)]

keep in mind that we do provide autobuilds for 0.24 as well, so you should be able to activate those for the purposes of this test.

http://www.mythbuntu.org/auto-builds

The site is down atm (but it might be up when you visit again), so you can also activate by manually adding the PPA with this command:

# sudo apt-add-repository ppa:mythbuntu/0.24

[Tommi Nieminen (tommi-nieminen)]

The bug doesn’t seem to affect the backend at all. Only the frontend crashes, but recordings are done OK and the resulting .mpg files can be viewed another media player such as VLC; which of course cannot be done from inside MythTV.

I will now try Mario’s autobuild advice and update both my backend server and the frontend machine to 0.24.

[MarcRandolph (mrand)]

Tommi, while 0.24 works well for some people, there are a number of open issues - so if there is a chance that you will need to revert back to 0.23.1, be sure to back up your database before upgrading to 0.24.

Changing to incomplete since upstream has said it needs to be reproduced on 0.24

[Tommi Nieminen (tommi-nieminen)]

Oops... Before I saw your msg, I had already rushed on to try out 0.24 (there was nothing really important to backup anyway).

And *wow*, the new version really seems to fix this issue!

[MarcRandolph (mrand)]

Thank you for reporting back. Marking as fixed (abet in a future release - likely 11.04).