[Solved] Re: Hardware decoding of video not working in VLC

[Celejar <celejar@gmail.com>]

On Wed, 13 Jun 2018 09:06:32 +0200
didier gaumet <didier.gaumet@gmail.com> wrote:

> Le 13/06/2018 à 06:00, Celejar a écrit :
> [...]
> > --avcodec-hw vaapi
> [...]
> 
> launching vlc with -vvv option  may be handy sometimes

Thanks! Using -vvv, I found this [hint for anyone else trying this:
look for amber lines ;)]:

avcodec decoder warning: thread type 1: disabling hardware acceleration

Searching the web turned up this thread:

https://forum.videolan.org/viewtopic.php?t=134770

Apparently, vlc uses ffmpeg libraries, which contain a limitation
preventing the simultaneous use of multithreading and hardware
acceleration. The workaround is to disable multithreading (although
there's a warning that this may adversely affect performance with
non-hardware-accelerated video):

https://forum.videolan.org/viewtopic.php?t=134770#p446037
https://forum.videolan.org/viewtopic.php?t=134770#p446154

Doing this reenables hardware acceleration, and CPU usage drops to
levels similar to those of mpv.

Thanks much!

Celejar