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View Full Version : what is your CPU load on Mpeg4 decoding?


Bluedan
30th September 2002, 12:07
Hi,
ATM, I'm unsure if there's something wrong lately with my system, because I found out that I suddenly have jerky playback of XVid or DivX movies beacause of high CPU load. I know that there may be a hundred reasons for this, though it's not easy for me to find out, for the system in total is running without problems.
So, at first I want to make sure that this is really an error and not "natural".
I'm running XP on a PIII unit @ 667MHz,
256MB RAM, main background programmes besides the usual services I haven't been tampering with: Tiny Personal Firewall, AntiVir.
WinDVD4 never exceeds 75-80% CPU capacity on 4:3 fullscreen, daylight scenes, no stills.
But Xvid or DivX decoding - w/ or ... \w (without?) ffdshow in the filter chain - it takes basically ~50/60% on totally black frames with only some letters ("presenting...."), a usual case at the beginning of a movie, and quickly rises to 99% on daylight scenes, already on 16:9 movies.
Quality with the original postprocessing filters, both Xvid and DivX 5.02, is set to lowest (=speed).
There's no difference if run from HD or CD with all drives on DMA transfer rates.
I've "converted" from W98SE to XP a few months ago an cannot remember having had problems with playback so far.
AGP runs at 4x66MHz with my TNT2 pro (anyway WinDVD is doing a good job!).
Latest XVid installed, also OGG-DSF. But it's the same problem with Avi files.
I raised gamma preset on startup for my video card, but I refuse to believe that it produces extra load on video decoding.
One of the latest installations was the firewall and the Antivirus programme. But I doubt that it interferes much with the Direct show system or whatever is to blame.
Oh, I forgot: I tested with bsplayer and Zoomplayer with the latter being more reliable in stability, but no differences revealed.

Any help would be appreciated, guys, because an essential part of my daylife is missing: ATM, I'm learning for my last exam and used to enjoy a movie at the end of a hard working day...so far...

Cradle22
2nd October 2002, 07:08
Well, if your cpu-usage is already at up to 80% with simple DVD-watching (which is mpeg2-video content), I am not surprised that the cpu goes to its knees when playing divX (or any mpeg4 codec) movies. They take a lot more computing power.

But I can tell from my own experiences, that at least a P3 1000 Mhz is up to the task, with best postprocessing enabled (and with really high res movies, I only encode at 704*x). My hardware player (build by myself) has that CPU on a cheapo VIA board with a GF 2 MX 400 and 256 MB RAM, Win 2000, and the cpu usage does not exceed 90 % at all...

ac3
3rd October 2002, 15:39
With my P4 2.4 Ghz and 1GB Rambus, ATI 128MB video card, playing on Divx 5.02 video 704x resolution, my CPU usage is about 60%+/-. 80% +/- if post-processing is set to highest. So your CPU usage is about normal.

sarahjh69
3rd October 2002, 19:55
a p3 500 and above is good for playing divx movies
if its jerky......right click on a playing movie
select the divx decoder filter options setting....
turn quality to minimum. you won't see any difference
and the movie should play back perfectly then.
(I assume you have dma enabled on your HD or DVD rom)

QQ
6th October 2002, 16:58
You raised gamma settings where? In display properties of NVIDIA driver or in codec settings? If latter, then, yes, they can dramticly increase power needed to show movies.

I run celeron 374 here, and i can play movies with almost best postprocessing settings :)

Defiler
6th October 2002, 18:56
I have made high-res DVD rips that drop frames on Athlon 850s + DDR, even without post-processing enabled. Given that 1GHz CPUs are $35 these days, I'd say it's time for an upgrade.