Opened 6 years ago

Closed 6 years ago

#11029 closed Bug Report - Crash (fixed)

mythfrontend crash on starting playback

Reported by: Stephen Robertson <stephengrobertson@…> Owned by: Jim Stichnoth
Priority: blocker Milestone: 0.26
Component: MythTV - Video Playback Version: Master Head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

The frontend crashes consistently on trying to playback certain recordings but only if they are not the first recording played back after mythfrontend is started. I think I am correct in saying that all my recordings will playback if they are the first to be played.

I have not established what is special about the ones that it crashes on. In my experimentation I have been using two recordings of the same show, on the same channel, using the same card, that were recorded 24 hours apart. One shows this problem and one doesn't These are HD recordings from Freesat in the UK. The problem is not specific to this though I get the same symptom on some recordings from an SD broadcast from DVB-T.

Attachments (7)

gdb.txt (110.8 KB) - added by Stephen Robertson <stephengrobertson@…> 6 years ago.
gdb output
version.txt (880 bytes) - added by Stephen Robertson <stephengrobertson@…> 6 years ago.
mythavtest-fail.txt (10.9 KB) - added by douglas.mackay@… 6 years ago.
mythavtest --loglevel debug -v general,playback,libav (crashed)
mythavtest-good.txt (30.9 KB) - added by douglas.mackay@… 6 years ago.
mythavtest --loglevel debug -v general,playback,libav (played)
valgrind.log.tar.gz (98.7 KB) - added by douglas.mackay@… 6 years ago.
valgrind log
valgrind.log-proper.tar.gz (488.0 KB) - added by douglas.mackay@… 6 years ago.
proper valgrind log - ignore previous
valgrind-combined.log.tar.gz (492.7 KB) - added by douglas.mackay@… 6 years ago.
valgrind & mythavtest combined log

Download all attachments as: .zip

Change History (13)

Changed 6 years ago by Stephen Robertson <stephengrobertson@…>

Attachment: gdb.txt added

gdb output

Changed 6 years ago by Stephen Robertson <stephengrobertson@…>

Attachment: version.txt added

comment:1 Changed 6 years ago by douglas.mackay@…

My crash reports for the same issue (one from a remote frontend and the other from the backend) are :- https://bugs.launchpad.net/mythbuntu/+bug/1041788 https://bugs.launchpad.net/mythbuntu/+bug/1041797

Further testing has shown that the crash is intermittent when mythpreviewgen is generating the preview. It only seems to affect BBC channels (SD, HD on both UK Freeview and UK Freesat)

Manually running mythpreviewgen on an affected recording can cause the crash about 50% of the time.

Sample (6MB) - http://www.filedropper.com/100120120826105500

comment:2 Changed 6 years ago by stuartm

Milestone: unknown0.26
Priority: minorblocker
Type: Bug Report - GeneralBug Report - Crash
Version: UnspecifiedMaster Head

Changed 6 years ago by douglas.mackay@…

Attachment: mythavtest-fail.txt added

mythavtest --loglevel debug -v general,playback,libav (crashed)

Changed 6 years ago by douglas.mackay@…

Attachment: mythavtest-good.txt added

mythavtest --loglevel debug -v general,playback,libav (played)

comment:3 Changed 6 years ago by douglas.mackay@…

I've attached two logs (one a crash the other played back ok) from mythavtest --loglevel debug -v general,playback,libav using the above sample.

It's seems to be hit or miss if it plays back. It can play back times then crash on the next attempt.

Changed 6 years ago by douglas.mackay@…

Attachment: valgrind.log.tar.gz added

valgrind log

Changed 6 years ago by douglas.mackay@…

Attachment: valgrind.log-proper.tar.gz added

proper valgrind log - ignore previous

Changed 6 years ago by douglas.mackay@…

valgrind & mythavtest combined log

comment:4 Changed 6 years ago by Stephen Robertson <stephengrobertson@…>

So far I am unable to reproduce this problem when building v0.26-rc-23-gb5fbc74 (with or without patch http://pastebin.com/7Pj1Kjke) locally but the problem is still very repeatable when same the version is installed via mythbuntu packages (Original report was from using mythbuntu packages)

comment:5 Changed 6 years ago by Jim Stichnoth

Component: MythTV - GeneralMythTV - Video Playback
Owner: set to Jim Stichnoth
Status: newaccepted

comment:6 Changed 6 years ago by Jim Stichnoth <jstichnoth@…>

Resolution: fixed
Status: acceptedclosed

In 92016b94983a4b8a6cb75dbc48893f5c05ce4620/mythtv:

Fixes #11029. Ensure AVPacket's data and size fields are initialized.

Without this initialization, mpegts_push_section() may try to access
uninitialized data and size fields from the AVPacket structure.

Note: See TracTickets for help on using tickets.