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Re: [OT] Minimum CPU speed for playing DIVX avis?



Nate Amsden wrote:
> 
> Viktor Rosenfeld wrote:
> >
> > Hi folks,
> >
> > I got mplayer (http://mplayer.sourceforge.net) working very nicely, only
> > that CPU utilization is constantly at 100% (~ 92% user, 8% system) and
> > sound is very broken after 10 seconds playing.  The video is fine
> > though.
> >
> > I have a 333MHz Celeron with MMX, use X 3.3.6 from woody, and have a
> > very shitty 4MB PCI graphic card.

> upgrade CPU and video card. 

Upgrading the CPU is unfortunatelly not an option, but I'll definately
get myself a new graphic card anytime now so I can use XFree 4.x.  I
looked at the file DOCS/SPEED of the Mplayer distribution and found some
very interesting data ...

-----8< snip >8-----
MPEG 1/2 Video codec CPU usage in percent (%) :
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1. Setup: mga_vid YUV, MMX idct, no mtrr settings
2. Setup: mga_vid YUV, SSE idct, with mtrr settings
3. Setup: Utah-GLX OpenGL + software C YUV->RGB, SSE idct
4. Setup: X11 Shm (32bpp) + software MMX YUV->RGB, SSE idct, with mtrr
5. Setup: null output (codec speed only)
6. Setup: X11 4.0.1e + Xv extension, SSE idct, with mtrr

                               1.   2.   3.   4.   5.   6.
  DolbyDigitalBroadway.vob:   60%  35%  78%  67%  26%  47%
  matrix.vob (trailer):       51%  30%  62%  56%  23%  40%
  PAL (352x288/25) mpeg1:     16%   9%  30%  13%   7%   8%
  3D anim (30fps mpeg1):      20%  14%  35%  25%  12%  14% 
-----8< snip >8-----

When playing to the null output (option 5) his CPU utilization is at
26%.  When I do the same CPU utilization peaks at 57%, but usually not
more than 48% or so.  So I have roughly a ratio of 57/26 = 2.19. 
Multiplied with his value vom X11 Shm (67%), I get CPU utilization of
146% -- no wonder that the sound is flaky!  But if I do 2.19 x 47%
(option 6), I'm at 103% peak usage.  It's gonna bog the CPU down, sure
enough, but it might just be fast enough.  If I get a Matrox card, I can
use his mga_vid driver (option 2) yielding 2.19x35% = 76% utilization!

Or maybe I'm just too optimistic.  :)


> testing now a 512x224(23fps) DiVx with 1500kbit/s 48khz stereo sound
> looks like aviplay is hoveraing around 25% utilization. doubling
> the size of the video(still windowed not playing fullscreen)
> increases cpu to 31-36%. fullscreen works fine too. never drops
> a frame or skips an audio beat
> 
> runnin 1600x1200x16bit @ 75hz. also playing the DiVx over NFS,
> so that may take some of the cpu ....who knows.

Good for you.  :)


Thanks,
Viktor
-- 
Viktor Rosenfeld
WWW: http://www.informatik.hu-berlin.de/~rosenfel/



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