Sudden problem encoding video

January 31, 2007 10:05 AM

I regularly use ffmpeg to encode videos (from mpeg2 to mpeg4) for my ipod. I've been doing this for nearly a year with no problems. Now, every time I start an encode, my system is suddenly under a lot of pressure - I can't use any other application. If I go into the windows task manager and set the priority to 'below normal', all is fine again. Anyone have any idea why this change might have occured, or any idea how I can get around it (preferably without using task manager)?

For info - i think this is a windows problem, rather than an ffmpeg problem. I suspect windows isn't allocating resourced properly anymore, for some reason. The same symptoms happen with other software sometimes - ffmpeg is just the one i use most.

posted by ascullion to Computers & Internet (5 answers total)

Best answer: That's odd. Have you upgraded to a new build of ffmpeg recently? Could be that it's setting a more aggressive scheduling priority than it did before.

Or maybe this is just another reason to be suspicious of the Windows scheduler.

How do you start ffmpeg? One option is to use the windows "start" command on the commanline, which will let you set the scheduling priority without dealing with task manager.

For example:
"start /LOW ffmpeg [your usual ffmpeg parameters]"
posted by Good Brain at 10:24 AM on January 31, 2007 [1 favorite]

Response by poster: nope, haven't changed ffmpeg. don't use the windows scheduler either.

what i have, without boring you with the details, is an epg programme (digiguide) which i use to put programmes on my ipod automatically. so, digiguide knows when i programme i like starts. it sends a message to my tv capture programme to record. when the recording is finished, it starts an ffmpeg process to encode to ipod format.

using the start command is a great idea though, will try that...
posted by ascullion at 10:41 AM on January 31, 2007

By "windows scheduler" I was referring to the thing that decides how to allocate CPU resources to running applications, not the little automatic command runner.

Sounds like setting the priority using the start command will help with your immediate issue, but offers no explanation why windows seems to be locking up on your more often lately.

Good luck.
posted by Good Brain at 10:57 AM on January 31, 2007

Response by poster: ah, i see. thanks for the help.

i'll probably do a complete reinstallation in the next month or two anyway, maybe an upgrade to vista even. so just need a sticking plaster for now.
posted by ascullion at 11:35 AM on January 31, 2007

Response by poster: for info if anyone's interested.. i am using the start command, but with /p so it runs in the same dos window, instead of launching a second one.

thanks good brain!
posted by ascullion at 1:04 PM on January 31, 2007