The VideoLAN Forums

Hi, VLC developers! My system is:

Ubuntu 16.04 32-bit with the standard Ubuntu repos, no third-party software installed
VLC 2.2.4
Video source to play: a local mp4/h264 file
How to reproduce the hang:

1. Open a local mp4/h264 file
2. Hit "Play" if it doesn't play automatically
3. Hit "Stop"
4. Repeat 2,3

I use QtPlayer and gtk_player from the VLC source code to test how libVLC works. My observation so far is that both demos hang in libvlc_media_player_stop() very often (see the testing steps above). The chance is around 2% that hitting the stop button hangs the application. Both the Qt and GTK demo applications hang in libvlc_media_player_stop(). Here is the stacktrace of the GTK application: https://pastebin.com/LQKfMFWJ

I also tried upgrading VLC to 2.2.8 with no luck. VLC 3.x cannot be compiled on Ubuntu 16.04 due to dependency errors. Any ideas? Thanks in advance!

Since you mentioned VLC 3.x, here is a possible way to install it:
1. Using VLC 3 under Ubuntu 16 or lower
To do this, make use of PPA.
sudo add-apt-repository ppa:jonathonf/vlc-3
sudo add-apt-repository ppa:jonathonf/ffmpeg-4
sudo add-apt-repository ppa:jonathonf/meson
sudo apt-get update && sudo apt-get install vlc
How to Restore:
You can revert back to stock version of VLC (2.2.2) in Ubuntu 16.04 by purging the PPA via command:
sudo apt-get install ppa-purge && sudo ppa-purge ppa:jonathonf/vlc-3
Also downgrade the FFmpeg libraries by purging the dependency PPA if you want:
sudo ppa-purge ppa:jonathonf/ffmpeg-4
Ref: http://ubuntuhandbook.org/index.php/201 ... 16-04-ppa/

The trace only shows one thread, not enough to find where the problem is.

The trace only shows one thread, not enough to find where the problem is.

What can I provide to better understand the issue? I'll do my best to grab the required information per your recommendations.

algrev

Since you mentioned VLC 3.x, here is a possible way to install it:
1. Using VLC 3 under Ubuntu 16 or lower
To do this, make use of PPA.

Thanks for the recommendation. I installed VLC 3.x from the PPA. Unfortunately looks like it's not able to use HW acceleration for some reason. The error is:

libva info: VA-API version 0.39.4
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/i386-linux-gnu/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_39
libva info: va_openDriver() returns 0
[b2a1d1b0] vaapi generic error: profile(3) is not supported
libva info: VA-API version 0.39.4
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/i386-linux-gnu/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_39
libva info: va_openDriver() returns 0
[a632f650] avcodec decoder: Using OpenGL/VAAPI/libswscale backend for VDPAU for hardware decoding
[mpeg4 @ 0xa6318e80] Failed setup for format vdpau: hwaccel initialisation returned error.
[a632f650] avcodec decoder error: existing hardware acceleration cannot be reused

The trace only shows one thread, not enough to find where the problem is.

Meanwhile, here is the full stacktrace grabbed with "thread apply all bt": https://pastebin.com/yEJ1Mrxe

The VLC timer code is locking up. Be sure to update to the latest VLC version.

This was indeed an issue for VLC 2.2.8. It got fixed after VLC 3.0+ tho. (tested with 3.0.4)

I still see the issue with VLC 3.0.6 from http://ubuntuhandbook.org/index.php/201 ... 16-04-ppa/. The only solution is to remove libxdg_screensaver_plugin.so.