Opened 10 years ago

Closed 9 years ago

#8261 closed Bug Report - Crash (Unverified)

[CRASH] SegFault when generating previews for certain HD-PVR recordings

Reported by: doug@… Owned by: jpoet
Priority: minor Milestone: unknown
Component: MythTV - General Version: Master Head
Severity: medium Keywords:
Cc: Rob Smith Ticket locked: no

Description

My HD-PVR occasionally corrupts the beginning of its recordings. The recordings are watchable (if I fast forward the beginning) however, the mythbackend preview generator process will segfault when generating previews for these recordings (e.g. from MythWeb). I'm currently running trunk 23865 and attached are two sample back traces.

Thanks! Doug

# mythbackend --version Please include all output in bug reports. MythTV Version : 23865M MythTV Branch : trunk Network Protocol : 56 Library API : 0.23.20100326-1 QT Version : 4.5.2 Options compiled in:

linux debug using_oss using_alsa using_pulse using_pulseoutput using_backend using_directfb using_dvb using_firewire using_frontend using_hdhomerun using_hdpvr using_iptv using_ivtv using_joystick_menu using_lirc using_mheg using_opengl_video using_opengl_vsync using_qtdbus using_qtwebkit using_v4l using_x11 using_xrandr using_xv using_xvmc using_xvmc_vld using_xvmcw using_bindings_perl using_bindings_python using_opengl using_vdpau using_ffmpeg_threads using_libavc_5_3 using_live using_mheg

Attachments (7)

mythtv_backtrace.201003301959.txt (13.7 KB) - added by Doug Haber <doug@…> 10 years ago.
mythtv_backtrace.201003302000.txt (16.6 KB) - added by Doug Haber <doug@…> 10 years ago.
CreateBuffers_check_NULL.patch (1.5 KB) - added by jpoet 10 years ago.
VideoBuffers::CreateBuffers?: check if av_malloc returns NULL
add_previewgenerator_logging.patch (545 bytes) - added by jpoet 10 years ago.
Add playback,extra logging to the preview generator
log.txt.gz (17.0 KB) - added by Doug Haber <doug@…> 10 years ago.
a.txt (8.6 KB) - added by dougt@… 9 years ago.
stacktrace
crash.txt (6.0 KB) - added by beirdo 9 years ago.

Download all attachments as: .zip

Change History (25)

Changed 10 years ago by Doug Haber <doug@…>

Changed 10 years ago by Doug Haber <doug@…>

Changed 10 years ago by jpoet

VideoBuffers::CreateBuffers?: check if av_malloc returns NULL

comment:1 Changed 10 years ago by jpoet

Can you please try the attached CreateBuffers_check_NULL.patch and see if it helps?

comment:2 Changed 10 years ago by Doug Haber <doug@…>

Awesome - thanks for the quick response - I'll check it out when I wake up tomorrow.

-Doug

comment:3 Changed 10 years ago by jpoet

Actually, that patch probably will not help. Should not hurt, but unlikely to fix the problem.

Please try add_previewgenerator_logging.patch and attach a log after the crash happens.

Changed 10 years ago by jpoet

Add playback,extra logging to the preview generator

comment:4 Changed 10 years ago by Doug Haber <doug@…>

jpoet - As you suspected, the first patch did not fix the segfault. Attached is the log.

Changed 10 years ago by Doug Haber <doug@…>

Attachment: log.txt.gz added

comment:5 Changed 10 years ago by Doug Haber <doug@…>

FWIW I get a SegFault? and see the error on the same line for mythcommflag as well

Changed 9 years ago by dougt@…

Attachment: a.txt added

stacktrace

comment:6 Changed 9 years ago by robertm

Owner: changed from Isaac Richards to jpoet
Status: newassigned

comment:7 Changed 9 years ago by Doug Haber <doug@…>

For what it's worth I still see this in trunk 25777 with mythpreviewgen.

comment:8 Changed 9 years ago by Rob Smith

Cc: Rob Smith added

Changed 9 years ago by beirdo

Attachment: crash.txt added

comment:9 Changed 9 years ago by beirdo

Not sure if that crash spew (from the console where I ran mythbackend) is deemed helpful or not. It may be pointing at an entirely different crash in mythpreviewgen.

comment:10 Changed 9 years ago by anonymous

sad... i was hoping that the recent ffpeg merge would have helped. it didn't.

comment:11 Changed 9 years ago by beirdo

See also #9063

comment:12 Changed 9 years ago by beirdo

Version: headTrunk Head

comment:13 Changed 9 years ago by anonymous

jpoet, can/will this be fixed for 0.24?

comment:14 Changed 9 years ago by beirdo

Summary: SegFault when generating previews for certain HD-PVR recordings[CRASH] SegFault when generating previews for certain HD-PVR recordings

comment:15 Changed 9 years ago by beirdo

See also #9596 (which was a DVB-T H.264 recording)

comment:16 Changed 9 years ago by beirdo

Status: assignedinfoneeded
Type: defectBug Report - Crash

A lot of things have changed in the code over the past year, is this still reproducable?

comment:17 Changed 9 years ago by Doug Haber <doug@…>

This is way out of date for me. It's probably more relevant to just open a new ticket if it happens again.

Thanks!
Doug

comment:18 Changed 9 years ago by beirdo

Resolution: Unverified
Status: infoneededclosed

Closing at user request.

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