VDM video rendering rate keeps dropping to 0fps

[Lux Delux]

Having a problem with the latest VDM (1.5.10.2).
When I'm encoding a movie the 'Video rendering rate' drops to 0.0fps.
And has little bursts where it goes to around 20fps (depends on what I'm encoding).
The weird thing is when I change the 'Processing thread priority' setting the fps goes up and drops again.
When I keep the dropdown focused and change the priority constantly the fps keeps at a steady fps!
So my pc is able to render at that speed. But for some reason vdm has problems 'focussing'.

The vdm process runs at normal priority, changing this (in windows task manager) doesn't solve this problem.

Some specs of the computer:
Pentium 4 3.00GHz
2GB ram
Windows XP sp2

Searching for this problem, leaves me with a lot of noise.
Since I am not sure where the problem is I can't really search on anything.

So if anyone has a clue on what the problem could be I would be really grateful.

Oh and my first post, howdy :)

[squid_80]

What codec are you encoding with (video and audio)?

[Ngr]

I have the same problem with a few differentiations:

1. My FPS drops to about 1-5 fps, not 0
2. If i use VirtualDubMod on its own, it doesnt present this problem, it only appears when i am using AutoGK, which in turn uses VDM

Normally my machine can sustain about 80fps first pass and about
55+ second pass using Xvid and a 640x??? resolution. But in 1 out of 3 occasions it exchibits this behavior. I have tried disabling avir and all other user processes to no avail.

[Pure]

What codec are you encoding with (video and audio)?

He's using XviD for the video (most likely 1.1.0 final) and the original AC3 stream for audio

[squid_80]

Using xvid with more than 1 thread on a single core machine can sometimes exhibit this behaviour.

[Lux Delux]

Does that also involve cpu's with hyperthreading?

And if that is the case, is it possible to only use 1 thread without disabling hyperthreading?

Thanks for the replies :)

[squid_80]

With hyperthreading you shouldn't be affected. But to be sure, in xvid's encoder config click "Other options..." and set the number of threads to 1.

[Lux Delux]

Thanks, will try it out :thanks:

[Pure]

Thanks squid_80, will give that a go aswell!

Cheers

[Ngr]

My machine is a dual xeon with hyperthreading. I had already tried disabling hyperthreading and also changing xvid thread from 0 to 3 with no apparent change. My other machine which is an AMD dual core never exchibited this problem.

[squid_80]

Are you sure it's not overheating? Intel cpus will slow down execution to cool down if they are getting too hot. Also do you see the same jumps in speed as described by Lux Delux when you flick thru the "processing thread priority" selections?

[Ngr]

Both machines are watercooled. The dual xeon idles at 29-30C and at load reaches 37-39C.
No, i dont see anything different if i flick the priority selection.
I have grabbed 3 screenshots of the VDM progress dialog exchibiting this behavior but will have to find a place to host.

[Your_Idol]

I had the exact same problem and I was getting droped frames as well and I did see that changing the "processing thread priority" would make it start encoding again too.

At the time I was using vdub to convert mpa to mp3 at the same time as my mpeg to avi and I wasn't sure weather it was the video or audio that was coming out wrong so I tried encoding them separately. Audio in belight and video in vdub and the problem went away.

Ever since I have been telling people to encode video and audio separately to fix all their vdub problems.