[MPlayer-dev-eng] [PATCH] A new ASS renderer

Vladimir Mosgalin mosgalin at VM10124.spb.edu
Mon Sep 24 11:16:42 CEST 2012


Hi Reimar Döffinger!

 On 2012.09.24 at 08:21:03 +0200, Reimar Döffinger wrote next:

> >> Even stranger: even without this patch, the driver does not use any relevant amount of CPU at all when using the OpenSource driver, basically freetype is using all of it (I used a trivially decodable video with those subs).
> >> Only the closed-source driver is a bit of an issue.
> >> I'll have to read up on the thread again, but did we ever figure out why some strange expand filter magic made a difference?
> >> Admittedly this is using some Radeon 5700 card.
> > 
> > Well, another quick check has shown that new versions of drm & mesa &
> > gallium made no difference: on Fedora 17 w/ Radeon 4870 there is exactly
> > same effect as on Fedora 14 with Radeon 1900.
> > 
> > The karaoke subtitles in question on 1920x1080 video raise CPU usage
> > from 36% to >100% (& >10% frames dropped) when rendered with vo_gl
> > compared to -vf ass; doesn't matter if it's in window or fullscreen.
> > 
> > I have karaoke and non-karaoke version of these subtitles. Non-karaoke
> > version prints line only on subtitles change
> > EOSD counts (tiny, small, all): 1, 1, 162
> > A:  23.2 V:  23.2 A-V:  0.000 ct:  0.075   0/  0  3% 26%  6.0% 6 0 68% 
> > EOSD counts (tiny, small, all): 1, 5, 178
> > A:  30.2 V:  30.2 A-V: -0.001 ct:  0.074   0/  0  2% 23%  6.2% 6 0 59% 
> > EOSD counts (tiny, small, all): 3, 5, 102
> > 
> > Karaoke prints it all the time
> > EOSD counts (tiny, small, all): 22, 2, 164
> > A:  16.7 V:  16.7 A-V: -0.000 ct:  0.053   0/  0  1% 29%  6.7% 0 0 74% 
> 
> Uh, MPlayer is of the opinion that it uses only 36% CPU, and only 6% more than the non-karaoke case.
> That matches what I am seeing, except that that really is the real CPU usage for me.
> I'm starting to think that there is something very specific to your setup going on.

No, that's just that 0.5 seconds of subtitles playback didn't change
average numbers accumulated over 10 seconds without subs. If left alone,
that number quickly climbs to 85-89% and tends to framedrop on minor
occurrence like window resize or background activity. Looks like I made
a mistake in original test: somehow, when no other processes are running
it *can* render subs in window without framedrop, however it's so
fragile so it's hard to notice.
When I switch to fullscreen, the second problem kicks in an I get CPU
usage numbers >100% + tons of framedrops right away.

-- 

Vladimir


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