Opened 13 years ago

Closed 13 years ago

Last modified 13 years ago

#1086 closed defect (worksforme)

ffmpeg crashes on broken mpeg2

Reported by: tomimo@… Owned by: danielk
Priority: minor Milestone: 0.20
Component: mythtv Version: head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

I have a MythTV box with two TT-Budget DVB-C cards and the mpeg2 stream does seem to have occasional errors in it. Now, almost every time whenever a recorded program has some slight errors in it and I use MythWeb to list all recorded programs WITH the option "show_recorded_pixmaps=true" the mythbackend starts looping with errors in creating the requested pixmaps and finally crashes.

I have attached a debug log and gdb-output which have been created with the following parameters:

handle SIGPIPE nostop noprint handle SIG33 nostop noprint set logging on set pagination off set args -v libav,playback,file &> log.txt run thread apply all bt full set logging off

This crash will happen every single time with certain recordings. If there is any need to get more information, I'll be happy to do more tests & debugging.

Attachments (2)

log.txt.bz2 (8.1 KB) - added by tomimo@… 13 years ago.
Mythbackend debug log generated with "-v libav,playback,file"
gdb.log.bz2 (12.2 KB) - added by tomimo@… 13 years ago.
GDB output / backtrace

Download all attachments as: .zip

Change History (10)

Changed 13 years ago by tomimo@…

Attachment: log.txt.bz2 added

Mythbackend debug log generated with "-v libav,playback,file"

Changed 13 years ago by tomimo@…

Attachment: gdb.log.bz2 added

GDB output / backtrace

comment:1 Changed 13 years ago by danielk

Milestone: unknown
Owner: changed from Isaac Richards to danielk
Summary: Mythbackend (SVN 8675) crashes while trying to create a Preview-picture with bad(?) mpeg2.ffmpeg crashes on broken mpeg2

Can you play one of the broken files with:

valgrind mythtv name-of-broken-file

And attach the log to this ticket

comment:2 Changed 13 years ago by danielk

Resolution: invalid
Status: newclosed

No response from the bug reporter to debugging request, closing ticket.

comment:3 Changed 13 years ago by tomimo@…

Resolution: invalid
Status: closedreopened

Not so fast, please! I tried unsuccesfully to run the mpeg2 file with valgrind yesterday evening, but the whole process ground to halt for some reason. I'll try again on this weekend to get the debug log you requested.

comment:4 Changed 13 years ago by tomimo@…

Ok, it seems like I'm unable to get valgrind to produce anything useful, as the whole debug process seems to get stuck with the error message "TV: Waiting for Valgrind..." again and again.

Therefore I've put a 20MB clip of the problematic mpeg2 file available as http://ncircle.nullnet.fi/mythtv/test.mpg in case you might be able to get more information out of the problem. This file produces an error of "[mpeg2video @ 0x111bcc0]get_buffer() failed (stride changed)" and goes into an eternal loop with ffmpeg codec. The file plays just fine with libmpeg2 codec.

comment:5 Changed 13 years ago by tomimo@…

I forgot to mention that I did try recompiling mythtv with --enable-valgrind, but it did not help in this case.

comment:6 Changed 13 years ago by danielk

Milestone: unknown0.20

comment:7 Changed 13 years ago by Isaac Richards

Resolution: worksforme
Status: reopenedclosed

Attached sample file plays fine all the way through with current SVN. Need a clip that exhibits the problem to debug further.

comment:8 Changed 13 years ago by tomimo@…

The playback problem has indeed been fixed in current SVN. Great!

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