Video rendering slows down. Any clues anyone?

[mbur]

Every time I convert a video file or watch a video on youtube things go at the expected speed at the start but the system seems to clog up and go slow as the job/view progresses. I'm running win XP on a HP lappy. Example, I'm running a conversion in Virtualdub. It started at 15-20 frames per second. Now, an hour later we are running at 2-4 fps and expecting to complete in 5 hours! I wouldn't be my ffdshow codec pack would it?

[Baldrick]

Use the windows task manager and see if virtualdub uses most cpu. Maybe something else is running and slowing everything down.

Set also the virtualdub process encoding to at least normal.

[jagabo]

The CPU may be overheating and automatically slowing down to prevent damage. Run a program like Core Temp and check your CPU. Blow any dust out of the laptop with a can of compressed air. Use a laptop cooler to provide additional cooling.

Note that most codecs are very fast at compressing all black frames, or unchanging frames. So if your video starts out with a few seconds of black frames or a simple logo that intro will compress faster than later shots with action.

[mbur]

Thanks Baldrik and jagabo. I'm using process explorer to keep an eye on things. This particular run is using an external codec (x264.exe) and it is getting a good chunk of cpu (ie 70-90%) when I'm not web browsing .

I seem to recall that the fan on this lappy used to go into 'overdrive' at times of heavy cpu use and I haven't heard that noise in a while. My jobs render rate was down to less than 0.5 fps and I put a external fan unit underneath and hey presto we are back up to 8fps.

I've just downloaded core temp. and am now watching my cpu temperature wobbling up and down in concert with the vdub frame rate . Pretty conclusive. i have a cooling problem. Thanks again!

[hech54]

I give up. What is a lappy?

[mbur]

I give up. What is a lappy?

LOL let me google that for you:
http://www.google.ie/search?q=lappy

@ jagabo: I'm going to put core temp in my start menu. It is just brilliant with the little temperature readout in the Taskbar. It should be part of the OS.

[poisondeathray]

I give up. What is a lappy?

LOL let me google that for you:
http://www.google.ie/search?q=lappy

You didn't do that correctly
http://lmgtfy.com/?q=lappy