[MEncoder-users] Performance on multi core machines - a specific enquiry re avisynth mt input

[Michael Rozdoba]

infernix wrote:
> Michael Rozdoba wrote:
>> I'm using mencoder under Windows XP as part of Megui. This is to encode 
>> to x264 2 pass, however as the input is an avisynth script which is very 
>> slow I'm performing a pre-render step where mencoder is used to 
>> transform the source via avisynth into an ffvhuff avi, which is itself 
>> subsequently passed into the 2 pass x264 encode.
>>
>> As the avisynth script is slow & avisynth natively doesn't make use of 
>> multi core cpus I'm using the mt (0.7) extension, which enables 
>> multithreading & exploitation of all cores.
> 
> I'm sorry if I'm jumping a bit late into this thread, but here's what I do.

/snip

> A sidenote for the people unfamiliar with avisynth, there's stuff you 
> can do in avisynth that mencoder can still only dream of. Hopefully with 
> libavfilter around the corner we'll have some more processing power there.

Thanks very much for the comments. Fortunately we have a full workaround 
- add a call to Distributor() at the end of the script. A proper fix 
needs a patch to MEncoder demux_open_avs() in libmpdemux\demux_avs.c, 
which checks the MT mode & if between 1 & 4 invokes Distributor.

No idea if anyone will implement, test & commit such a patch though. I 
had a go at writing one but haven't got around to testing it as I was 
having build problems & also was unclear about one aspect of the 
avisynth interface.

-- 
Michael Rozdoba