Performance Tuning H264 [Was: Re: [MPlayer-users] howto play apples quicktime movie trailers (720p)]

[Markus Schulz]

Am Mittwoch, 11. Januar 2006 09:30 schrieb RC:
> On Tue, 10 Jan 2006 19:48:09 +0100
>
> Markus Schulz <msc at tastatur-junkie.de> wrote:
> > prints mplayer this line?
> > SwScaler: using unscaled Planar YV12 -> BGR 16-bit special
> > converter
>
> Yes, exactly that.
>
> > But in booth cases the cpu reaches only a load between 60-80%
> > (2.2GHZ fixed frequency). And this is really curious to me, the 
> > software scaler should use as much cpu he cant get or not?
>
> As Reimar has explained, YUV->BGR16 conversion is extremely fast, so
> CPU speed is not the bottleneck.  Perhaps your AGP card is running
> at 1/2X instead of the 8X it is supposed to?  Perhaps DMA is disabled
> for some reason?  Perhaps the 64-bit NVidia driver is buggy/limited?

i think the problem with lower then max cpu load in benchmark mode has 
something to do with "sync to vblank". Cause i can't see any tearing 
with -vo gl. If i'm using -vo xv i see heavy tearing in benchmark mode. 
(dont use the xv-overlay, with overlay there also no tearing)

Now i've played a little bit with the environment variables 
__GL_SYNC_TO_VBLANK and __GL_SYNC_DISPLAY_DEVICE (but don't use 
twinview) without any success. Always looks like syncing to vblank.
But the variable __GL_SYNC_TO_VBLANK works fine, cause:

xxx at yyy:~/$ export __GL_SYNC_TO_VBLANK=1
xxx at yyy:~/$ glxgears
430 frames in 5.0 seconds = 85.793 FPS
428 frames in 5.0 seconds = 85.542 FPS
xxx at yyy:~/$ export __GL_SYNC_TO_VBLANK=0
xxx at yyy:~/$ glxgears
17183 frames in 5.0 seconds = 3436.543 FPS
17018 frames in 5.0 seconds = 3403.459 FPS

Perhaps mplayer enables the sync to vblank by -vo gl?

-- 
Markus Schulz