[SOLVED] Slackware current - MPlayer + ffmpeg-3.3 segfault

orbea · 05-07-2017, 09:54 AM

I noticed that ffmpeg-3.3 was added to current and as I have been building both MPlayer and ffmpeg myself for a while I noticed that it now segfaults with ffmpeg newer than 3.2 when switching between videos in a playlist. So in the event anyone else will now run into this issue I thought it'd be best to mention it here since upstream doesn't seem to care.

A playlist can be made with a command like this.

Code:

find -maxdepth 1 -type f -iregex ".*\.\(flac\|mp3\|ogg\|wav\|avi\|mkv\|mp4\|ogm\|webm\)$" | sort > playlist

And then played with.

Code:

mplayer -playlist playlist

Pressing '>' for the next track a few times should reproduce it.

A backtrace for the segfault made with both ffmpeg and MPlayer built with debugging symbols.

https://pastebin.com/bFYN0DPn

An issue report for MPlayer.

https://trac.mplayerhq.hu/ticket/2324#ticket

Alien Bob · 05-07-2017, 10:05 AM

I cannot reproduce this.

Edit: OK, I spoke too soon. I have my own ffmpeg installed... so my report is null & void.

orbea · 05-07-2017, 10:18 AM

It potentially could be just me, which I guess is good for everyone else.

orbea · 05-07-2017, 10:30 AM

Actually, you got me to look at this a bit closer and I think its connected to hwdec as I can not reproduce it without it. Possibly only with nouveau? Following the directions from the nouveau documentation I installed the required firmware and configured mplayer.

~/.mplayer/config

Code:

vo=vdpau
[vo.vdpau]
vc=ffmpeg12vdpau,ffwmv3vdpau,ffvc1vdpau,ffh264vdpau,ffodivxvdpau,

nvidia-firmware (blob version doesn't seem to matter so I used what nouveau documented)
https://slackbuilds.org/repository/1...vidia-firmware

Upstream documentation
https://nouveau.freedesktop.org/wiki/VideoAcceleration/

orbea · 05-07-2017, 12:52 PM

To make this worse it the backtrace is not the same every time and it does not crash in valgrind. It also occurs with the llvmpipe here so I guess its not only nouveau. It would be helpful if someone with intel or amd hardware using the free drivers in mesa could try to reproduce this too.

MPlayer Memory map - https://pastebin.com/QSTGYUPy
gdb log 1 - https://pastebin.com/Kb75BJJ7
gdb log 2 - https://pastebin.com/VyYN5JPrin
valgrind - https://pastebin.com/ExYmAEgK

elcore · 05-08-2017, 06:57 AM

Possibly unrelated but I had to downgrade from 3.3 > 3.2.4 because it would break often on x264/ffh264vdpau
Hard to reproduce the issue cause sometimes the file plays fine, sometimes just freezes the machine.
The same file can play perfectly and freeze the next time it's opened, and it's not just one file, I've tested about a dozen mp4 and mkv files.

willysr · 05-08-2017, 07:14 AM

I tested this on my desktop and i can't reproduce it. Pressing ">" several times jump to the next song in the playlist.

PS: I always rebuilt ffmpeg using Slackware's ffmpeg SlackBuild script with no changes nor additional parameters since i may have more additional libraries installed from SBo that may be auto-detected by ffmpeg.

SpiderTux · 05-08-2017, 08:10 AM

No problem here with clean current-May.6.2017

orbea · 05-08-2017, 11:21 AM

Thanks for the additional tests. I guess it seems likely there is something specific in my setup causing this. I can try bisecting ffmpeg when I have a chance to see where this started...

Quote:

Originally Posted by elcore

Possibly unrelated but I had to downgrade from 3.3 > 3.2.4 because it would break often on x264/ffh264vdpau
Hard to reproduce the issue cause sometimes the file plays fine, sometimes just freezes the machine.
The same file can play perfectly and freeze the next time it's opened, and it's not just one file, I've tested about a dozen mp4 and mkv files.

This sounds familiar, except that only MPlayer freezes/crashes for me.

orbea · 10-31-2017, 08:51 AM

This was caused by memory corruption in ffmpeg and appears to have been solved in ffmpeg-3.4.

More specifically in this commit.
https://git.videolan.org/?p=ffmpeg.g...eae06453f65668