[MPlayer-users] ass subtitles, vo gl and amd video

[Reimar Döffinger]

Nick Koretsky <nick_koretsky at ukr.net> wrote:
>On Tue, 24 Sep 2013 11:44:27 +0300 
> Nick Koretsky <nick_koretsky at ukr.net> wrote:
>
>> On Mon, 23 Sep 2013 23:56:22 +0400 
>>  Vladimir Mosgalin <mosgalin at VM10124.spb.edu> wrote:
>> 
>> 
>> > Somehow these subtitles render as complete garbage for me
>(oversized
>> > overlapping letters), but while mplayer has major problems
>rendering
>> > them both with -vo gl and -vf ass methods, mpv player works great
>and
>> > has no performance problems at all. Give it a try, maybe :)
>> > 
>> 
>> mpv has exact same problem with this subs on a8 with -vo=opengl, but
>has
>> no problems with -vo=opengl-hq
>
>After reading mpv docs about what opengl-hq is and doing some
>experiments i
>have narrowed it down to pbo option. But on mplayer force-pbo makes no
>difference.

I have no idea what you read.
Either way force-pbo is the default on AMD GPUs, so if anything noforce-pbo should be used.
But either way it does not affect subtitles in MPlayer (and I tested it, it does not help anyway).
mpv probably uses a different method entirely, like VDPAU for example does.
None of all this explains why -vf ass would show fairly bad performance as well, unless maybe an issue with libass.
For example it might be that it would help if it cropped completely transparent parts.