XVID Decoding too much cpu intensive!

[Caleb666]

Hey,

I've compared XVID & the latest DivX and found out that when playing an XVID movie while downloading some stuff the movie would come out choppy and stop at some moments.

But DIVX played perfectly!

I'm using Nic's latest DShow filter.

Does anyone have any idea if the XVID decoder is going to be optimized too?

I got a P4 1.8ghz.

[JohnMK]

As a stopgap solution, you could switch to Koepi's decoder.

[Caleb666]

Is there any difference ?!

I thought Koepi was using Nic's decoder :confused:

[athos]

I would suggest you try ffdshow

[OBcecado]

Hi, in an athlon 900 with windows 2000 sp4 i get 100% cpu load either with XviD's Dshow filter or ffdshow's libavcodec.
Is this normal? Shouldn't ffdshow require less cpu usage?



Thanks in advance.

[masken]

Very simply put: In Windows, all programs are always given 100% CPU, When they ask for CPU. If more than one app asks for CPU, then the 100% gets divided equally when the apps asks for CPU. A program not doing anything doesn't ask for CPU, it just resides in memory. This could also be the case for functions in the app that has been cached.

When playing a movie though, nothing can be cached as there's a constant decode of the content. Thereby the "100%"...

Correct me if I'm wrong heh ;)

[bill_baroud]

hmm ... my cpu occupation is about 30% on my XP1600 for any video content at 640x*** using ffdshow (bigger resolution use more cpu eh ;) )

... and an application doesn't eat 100% cpu if it doesn't need 100% :)
it request what it need and in case of multitasking, the taskes are scheduled, the system try to respect the time constraints of each task. So lags appear (basically) when you don't have enough CPU or if the system's scheduling fail.

[BoNz1]

Hi, I too have a p4 1.8ghz and I am able to decode everything fine without any choppyness and my cpu usage is always 30% or less using nic's decoder or ffdshow. I don't think the decoders are the source of your problems they are already really fast rather this is your problem, I bet:
when playing an XVID movie while downloading some stuff
Some of these p2p clients really hog your resources and sometimes might take 100% cpu even when you aren't playing your movies. Some people I know like to use clients like overnet and I have noticed a lot of times especially when it is downloading you can't even use the computer.

[visigotik]

Graphics card & drivers can also make a difference.
I Remember i also had a problem once with slowdowns on bsplayer, wich was caused by using some crappy bsplayer skins.

[frodoontop]

In fact I found xvid to decode faster than divx. Probably you didn't turned the same features on. For instance Qpel is heavy to decode(to encode as well).

Another reason could be the soundtrack. If it's AC3, you should try to update your filter. Older filters resulted in choppy playback.

You could also set postprocessing to a lower level. Without postprocessing I am able to play XVID flawless in 640*xxx on a AMD 800 TB.

Something you might try is to set the priority of the php-program to lowest and look if it helps.

[trbarry]

I encode some things at 1280x720. Recently I've gotten lazy and started to encode many things as just a 1 pass CBR, mostly for playability.

Otherwise in VBR there can be stuttering in the parts with highter bit rates though I suppose I could figure out how to instead manage the max bit rate properly. But CBR gives the most predictable playback results if you aren't sure you will have enough power on the target playback machine.

I also found I should avoid b-frames, qpel, and GMC. All have a very noticeable performance hit on playback.

Also, on at least one machine with a Matrox G400, playback depends upon the display resolution. Setting the display resolution higher hinders playback performance slightly.

Playback speed also depends upon the video cards color depth setting. Various cards seem to be happier at a 16, 24, or 32 bit color depth.

- Tom

[junglemike]

I have a couple of old machines that i usually use for mpeg4(mostly xvid) playback. Celeron266 without any cashe( overclocked to 400mhz) can decode almost any content, except those files, that have big resolution (7xx) and was coded using some advanced features qpel,etc.
On other machine P3-500 mhz i can playback ANY mpeg4 content with Nic's decoder of ffdshow. I just tried some 720x576 Xvid file using all adv. xvid setting with ac3 audio and maximum pp settings - On p3-500 bsplayer takes 80-90 % cpu but no choppy even for a second.(video is very poor - only 4mb but supports overlay. i have win2k,128ram.)
If there's other application which takes cpu usage like (most p2p clients do) you can set higher priority to player process,(but not realtime) In this case, even if there is some other app, that intends to take 100% cpu (like encoding), win2k/xp will first give all needed cpu power to player and only (if) smth is left - give it to other app, that require cpu.
In the same way, you can lower priority of the app, that intends to use cpu power.