Opened 10 years ago

Closed 10 years ago

#6720 closed defect (fixed)

m2ts playback broken by ffmpeg resync

Reported by: robert.mcnamara@… Owned by: Janne Grunau
Priority: major Milestone: 0.22
Component: MythTV - Video Playback Version: head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

Since the ffmpeg sync, playback of direct-from-bluray m2ts files is broken. Attempt to play them begin with an extremely long pause of a minute or two, then a segfault. Backtrace and log with -v most attached. Small sample has the pause but eventually plays back, and the network traffic seems to imply that a large amount of data is being transferred. Large files crash every time.

Attachments (3)

m2tsfail.log.gz (57.3 KB) - added by robert.mcnamara@… 10 years ago.
Log with -v most
gdb.txt (68.5 KB) - added by robert.mcnamara@… 10 years ago.
GDB backtrace
mythavlog.log.gz (21.7 KB) - added by robert.mcnamara@… 10 years ago.
log with libav,playback

Download all attachments as: .zip

Change History (9)

Changed 10 years ago by robert.mcnamara@…

Attachment: m2tsfail.log.gz added

Log with -v most

Changed 10 years ago by robert.mcnamara@…

Attachment: gdb.txt added

GDB backtrace

comment:1 Changed 10 years ago by robert.mcnamara@…

Note that this segfault is harder to trigger with gdb running-- Between pressing the "play" button and the segfault, exactly 2GB of data is transferred. Seems that it's trying to parse all the way through the file rather than play it.

Changed 10 years ago by robert.mcnamara@…

Attachment: mythavlog.log.gz added

log with libav,playback

comment:2 Changed 10 years ago by robert.mcnamara@…

Behavior of the bug has changed slightly. Now the video plays after *exactly* two minutes. Note the log output here:

2009-07-19 22:12:46.720 TV: StartPlayer?(0, Watching Video, main) -- begin 2009-07-19 22:13:46.248 Tuning to 'MPEG Program 0' pnum: 0x0 without CRC check on PMT 2009-07-19 22:14:46.041 AFD: Stream #0, has id 0x1011 codec id H264, type Video, bitrate 0 at 0x2a450f0

But while it now plays, sometime in the past several days, all decoding of the video has been broken in these files. See attached log.

comment:3 Changed 10 years ago by robert.mcnamara@…

20 MB Sample that exhibits some delay (not the full delay, file is too small) and shows decode errors:

http://www.fecitfacta.com/m2tssample.m2ts

comment:4 Changed 10 years ago by Janne Grunau

Milestone: unknown0.22
Owner: changed from Isaac Richards to Janne Grunau
Status: newaccepted

comment:5 Changed 10 years ago by Janne Grunau

(In [20971]) sync the mpegts demuxer even more to the upstream ffmpeg source

fixes corruption for the example in Refs #6720 introduced in [20961]

comment:6 Changed 10 years ago by Janne Grunau

Resolution: fixed
Status: acceptedclosed

reported as fixed on irc

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