[XviD-devel] multithreading

[Lars Täuber]

Hi there.

I'm a heavy user of xvid to transcode my private camcorder videos to xvid mostly using avidemux.
I want to thank you very much for your work! Go ahead!

Lately I got a 3-core computer and wonder why the threading of xvid is so bad scaling with the available cores.
In avidemux I set the xvid threads manually to 12 but only get a cpu usage of around 250% even on the second run of 2-pass encoding. The first run is at about 175% cpu usage max.

Could you elaborate the threading model for xvid in simple words? Are all threads encoding a single frame until it's finished?

I took some thinking about how I would do it and therefore liked to know if the first run on a 2-pass encoding fixes the series of frame types? In other words does the 2 run of a 2-pass encoding knows the frame type (I, P, B) to encode to of every frame in advance?

Mostly I do batch encoding all the videos of the last weeks. And am thinking of changing my encoding scheme to multiple encodings in parallel using only 1 thread for every process.

Thanks
Lars
-- 
Lars Täuber <lars.taeuber at web.de>