Mobile capturing?
January 22, 2006 5:31 PM   Subscribe

CaptureFromMyPassengerSeatFilter: I've just got back from driving around my neighborhood with my webcam attached to the sun visor and linked to my laptop in the passenger seat. After about 3 mins shooting, the capture goes from super smooth to super jerky - what is causing this bottleneck?

It's this webcam and my laptop is a P3 800, 256Mb RAM USB 1.1 Thinkpad. I know that's not the fastest kid on the block, but I do have video conversations for over an hour so why can't I capture for longer?
posted by russmail to Computers & Internet (9 answers total)
 
I may be wrong, but home webcam use (the compression/saving algorithms) takes advantage of the fact that the background doesn't change as you do things. A moving car would be much more intensive.
posted by stratastar at 5:40 PM on January 22, 2006


Is it on battery? Is your laptop putting the hard drive to sleep after 5 minutes? That would explain it.
posted by drstein at 5:41 PM on January 22, 2006


Response by poster: drstein: I just checked my power scheme and yes, the hard drive turns off after 5 minutes. But surely that only happens if there isn't any activity?
posted by russmail at 6:03 PM on January 22, 2006


It might be turning off when there isn't any input (like mouse or keyboard) activity. This might be worth getting a car power outlet -- it sounds really cool.
posted by dness2 at 6:43 PM on January 22, 2006


It might be that it captures video to RAM, and once that's full, it has to write to the HD which takes longer and so frames start dropping. I'm not sure about that, but it seems possible.
posted by willnot at 9:24 PM on January 22, 2006


Response by poster: Yes - I'd be inclined to agree with you willnot: I just did some experiments it's definitely not the hard drive turning off.
posted by russmail at 10:06 PM on January 22, 2006


Some sort of problem with caching?
posted by Thorzdad at 7:35 AM on January 23, 2006


Some laptops have processors which drop their speed when powered by batteries in order to conserve battery power. Maybe your laptop is reducing the processor speed after a certain period of 'inactivity'?
posted by blag at 7:37 AM on January 23, 2006


If you're running Windows XP you can set your CPU to run at Max Speed even on battery with Speedswitch XP.

Is your screen saver kicking in at 3 minutes? Windows prioritizes the task in the foreground (by default, at least), and the screen saver kicking in could be making the task doing the capturing lose priority. The screen saver could just be using a few too many cycles, too.
posted by kableh at 9:40 AM on January 23, 2006


« Older Can I use drop-down menus in Word for Mac?   |   What fonts used in this wine label? Newer »
This thread is closed to new comments.