sped up clip crashes openshot during playback

[Jon Charnas]

Using OpenShot 1.1.1 on Gentoo amd64 using ebuild found here: http://bugs.gentoo.org/283673

When changing the playback speed of clips to other than normal and attempting to play a preview of the timeline, openshot crashes when reaching the modified speed clip. Have only tried speeding up yet - can't confirm on slow down.

Changing playback speed property then saving results in being unable to remove or restore playback speed of the clips in question - right click on the clip crashes openshot again.

[Jon Charnas (goeland86)]

Addendum: when trying to export the saved clip, the terminal output ends with a segfault, again where the sped up clip is supposed to start. The exported video also has erroneous video playback speed, though photos are playing at the right speed, the transitions are at the proper place in the timeline still. Will try to clarify exactly what's happening with playback speed.

[Jon Charnas (goeland86)]

When trying to modify playback speed of the only clip in the timeline, with audio disabled (this is a .MTS file, directly copied from digital camera) the terminal output is as follows:

--------------------------------
   OpenShot (version 1.1.1)
--------------------------------
A new frmMain has been created
state saved
on_tlbImportFiles_clicked called with self.tlbImportFiles

(openshot:27606): GVFS-RemoteVolumeMonitor-WARNING **: remote volume monitor with dbus name org.gtk.Private.HalVolumeMonitor is not supported
project modified: Added file
state saved
project modified: Added clip
state saved
project modified: Changed visibility of clip
state saved
project modified: Moved clip
state saved
project modified: Changed visibility of clip
state saved
project modified: Changed audio of clip
state saved
on_mnuClipProperties_activate
on_txtOut_value_changed
on_cboKeyFrame_changed
on_cboSimpleSpeed_changed
on_frmClipProperties_configure_event
on_frmClipProperties_configure_event
on_cboSimpleSpeed_changed
on_btnClose_clicked
project modified: Modified clip properties
state saved
on_tlbPlay_clicked called with self.tlbPlay
Segmentation fault

The same occurs when attempting to slow down a video (tested with a .mov file converted from the file above, again with audio disabled, as well as a .avi conversion of the same file). I'm using the ~amd64 keyword on gentoo - unclear if newer libraries could be responsible for this.

[Olivier Girard (eolinwen)]

Strange this segfault. It looks that you have a problem with your monitor. Two tracks.
Your hardware is not enought power for working with HD files, a quad -core is the best.
So, you could work this file after a conversion with EKD for exemple in a format less "big".
Another thing, could you gdb for identify the segfault. More explanations how to use here : http://openshotusers.com/forum/viewtopic.php?f=12&t=180&p=647&hilit=gdb#p647
You must be in /usr/share/openshot for launching "run openshot.py". With this tool, we will have more explanations on the segfault. Thanks

[Jon Charnas (goeland86)]

Here's the backtrace from gdb when attempting to speed up an avi clip by twice the speed (audio disabled):

#0 0x00007fffe9739581 in av_find_opt () from /usr/lib/libavcodec.so.52
#1 0x00007fffea4e8920 in ?? () from /usr/lib64/mlt/libmltavformat.so
#2 0x00007fffea4e8ff0 in ?? () from /usr/lib64/mlt/libmltavformat.so
#3 0x00007fffed86cc3f in ?? () from /usr/lib/libmlt.so.2
#4 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#5 0x00007fffed86c99c in ?? () from /usr/lib/libmlt.so.2
#6 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#7 0x00007fffed86fc37 in ?? () from /usr/lib/libmlt.so.2
#8 0x00007fffed86cc3f in ?? () from /usr/lib/libmlt.so.2
#9 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#10 0x00007fffed86d47e in ?? () from /usr/lib/libmlt.so.2
#11 0x00007fffed86cc3f in ?? () from /usr/lib/libmlt.so.2
#12 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#13 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#14 0x00007fffed871bce in ?? () from /usr/lib/libmlt.so.2
#15 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#16 0x00007fffed871fc1 in ?? () from /usr/lib/libmlt.so.2
#17 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#18 0x00007fffed871fc1 in ?? () from /usr/lib/libmlt.so.2
#19 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#20 0x00007fffed872aa8 in ?? () from /usr/lib/libmlt.so.2
#21 0x00007fffed86cc3f in ?? () from /usr/lib/libmlt.so.2
#22 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#23 0x00007fffed86b3e5 in mlt_service_get_frame () from /usr/lib/libmlt.so.2
#24 0x00007fffed870537 in mlt_consumer_get_frame () from /usr/lib/libmlt.so.2
#25 0x00007fffe7283b7c in ?? () from /usr/lib64/mlt/libmltsdl.so
#26 0x00007ffff7826894 in start_thread () from /lib/libpthread.so.0
#27 0x00007ffff6f0ff9d in clone () from /lib/libc.so.6
#28 0x0000000000000000 in ?? ()

So if I'm reading this right it's an mlt problem, not openshot. I recently upgraded to mlt 0.5.2, and openshot 1.1.2, and the problem still exists. I was hoping to find that it had been fixed in the latest code, but clearly not.
My laptop is a dual-core Turion at 2 GHz, 4 GB of ram, and ATI graphics. I'm currently running the opensource radeonhd driver, because of lack of support for Xorg 7.5 from the binary ati drivers. I will switch back to the binary drivers soon, as 10.4 drivers are supposed to have up-to-date kernel and Xorg support.

Also, it is worth noting that playback of 720p files using mplayer or vlc is perfectly smooth. Not quite sure it's a system resources problem.

[Olivier Girard (eolinwen)]

Hum. Difficult to say exactly what 's happen. Have it crashed when you have play/work the file ? Nothing else after the "28 ?
MLT seems having a problem but i can't tell the which.

Also, it is worth noting that playback of 720p files using mplayer or vlc is perfectly smooth. Not quite sure it's a system resources problem.
It is different for playing a file in a player like Mplayer or Vlc and working with a HD file. For exemple, i was having the last year a Athon +3700 on which one i can play/read a HD file but i can done something with. Now, i have none problem with my two lasts configurations; a dual-core (AMD) and a Quad-core i5 750 (Intel).

[Jon Charnas (goeland86)]

No, nothing after #28. That's all it had, it then returned to the gdb prompt.
If it's MLT having a problem, it's an MLT bug, no?

This laptop, like I said, has a Turion X2 RM-70 (@2GHz), with 4 GB of RAM. The system hardware should not be an issue (in my mind), unless it's the hard drive read speed that's too slow, but again, unlikely as it's a 7200 RPM SATA drive. This laptop is just about a year old now, and should not be having issues working with HD video files.

[Olivier Girard (eolinwen)]

No, nothing after #28. That's all it had, it then returned to the gdb prompt.
If it's MLT having a problem, it's an MLT bug, no ?
Good question that i can not answer for the moment, i must search how have a better backstrace.

I said that because i have already seen that .More explantions here : http://openshotusers.com/forum/viewtopic.php?f=11&t=169 (i hope that the good link that i have given you !!)

Stay tuned for the backstrace ,i'm searching how have more informations on this. Normaly, i have already some feedbacks with so perhaps it is really a bug of MLT but i want to be sure before.

[thekeyboardbum (thekeyboardbum)]

Same problem here. Using gentoo linux, amd64. Had problems manually (complained about MLT libraries not being placed in the right place.)

This is the ebuild I used.
 http://bugs.gentoo.org/attachment.cgi?id=226677

[thekeyboardbum (thekeyboardbum)]

I found out that if you change the speed of a clip, apply the settings, and then try to go back into the properties it crashes. After using a lot of print statements I found the call that causes the problem:

In classes/video.py the last call to "self.c.start()" in the function load_xml crashes.
At the beginning of load_xml we have 'self.c = mlt.Consumer( self.profile, "avformat", export_path)'.

I'll investigate more tomorrow.

[thekeyboardbum (thekeyboardbum)]

Oops, wrong line, meant elf.c = mlt.Consumer( self.profile, "sdl_preview" ) . So it does seem possible it's a mlt issue at this point or it's being used/set up improperly at least.

[thekeyboardbum (thekeyboardbum)]

Fixed the issue. It was related to mlt not being compiled right. I had to download sources for mlt and use the below configure command

./configure --enable-gpl --disable-mmx --avformat-swscale -avformat-ldextra=-lmp3lame -lfaad -lfaac -lxvidcore -lx264 -lvorbis -ltheora -lvorbisenc -logg -lbz2 --debug --swig-languages=python

Please note that if you already have mlt installed on the system please remove it before doing make install. Otherwise the updated libraries won't load.

Also the make for mlt does not install the libraries to the right place. Copy mlt.i mlt.py mlt.pyc and _mlt.so in mlt-version/src/swig/python/ to your python directory (such as /usr/lib/python2.6/).

[Jon Charnas (goeland86)]

Thanks for the heads up, keyboardbum :)

Appreciate the fix, even if it is a bit of a hack ;)

I used MLT straight from the ebuild, I'll check which options I can get set properly with the USE variable.

[Andy Finch (fincha)]

mlt packaging issue on gentoo.

[Matthias Jansen (mail-matthiasjansen)]

Thanks to thekeyboardbum for finding out that it is a configure problem of mlt.

After a lot of testing, I found out that it is the kde USEFLAG, which causes the problems. When it is not set, the configure parameter "--disable-kdenlive" is set and then openshot crashes. So, for some strange reason, mlt has to be build with kdenlive enabled in order to work correctly with openshot.

[skywriter (xxxiter)]

OpenShot 1.4.1, MLT 0.7.6 from sunab's PPA.
Crashes when playing clips which speed was changed: segmentation fault.
Would recompiling of MLT help me?

[skywriter (xxxiter)]

crashes for me

[Jonathan Thomas (jonoomph)]

When compiling MLT myself, I get no crashes speeding up and slowing down clips. So, this might be a problem with the Sunab PPA, rather than a general OpenShot of MLT bug. I would suggest sticking to your default version of MLT, or upgrading your distribution to a newer OS (with all the official libraries). Good luck.

[skywriter (xxxiter)]

Have healed by replacing sunab's MLT with default Ubuntu's MLT 0.5.4.