Two pass video encoding
 

I'm going on an international trip later this year and I've started ripping some DVDs to put on an external HDD to use with a laptop for the trip. Two-pass encoding will obviously result in a better quality rip but I've got a quick question relating to SMP (dual-core systems) and the encoding process.

As mencoder requires two running processes using this method, would I be correct in assuming that each would run on a different core which would make two-pass a considerably smarter option than single-pass? When encoding a DVD with a single-pass, top reports that one core is doing all the work which makes sense so logically a second encoding process using the second core would be a better option.

Anyone know more about this willing to weigh in an opinion?

Thanks :)

the second pass uses information derived from the first pass. afaik they MUST run sequentially, not consecutively.

I agree. You need a complete pass to have the correct information for the second pass. Still, if you are just looking for a diversion to watch on a trip, a single pass should be fine.

Okay, thanks for the info guys :)

in my head, two pass encoding works by doing an initial scan encode of the film and recording how well the encoding works on each frame as it goes along. once completed you have a record of where more quality is needed (i.e. more disk space - high motion scenes etc...) and other parts of the film where the detail is not needed and so borrow that space in the knowledge that you can afford it on the whole.