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

[James Hastings-Trew]

Michael Rozdoba wrote:
> James Hastings-Trew wrote:
>   
>> Michael Rozdoba wrote:
>>     
>
>   
>>> Can anyone comment on why avisynth is being restricted to one core 
>>> /only/ when it's being used as input to mencoder?
>>>
>>> I could really use a solution as I've just discovered my alternative 
>>> solution - vdub & ffdshow's huffy, is introducing a yellow colour cast 
>>> (probably as it requires an additional converttorgb step at the end of 
>>> the avisynth script, as vdub will only accept rgb).
>>>       
>
> Aside: fixed this - it wasn't the conversion at the end of the script to 
> rgb (or yuy2 which had the same effect), but the fact that within vdub I 
> had huffyuv configured to compress in yv12 space; that conversion was 
> producing the cast. Changing the script to output yuy2 (it had been 
> working in yv12 which vdub wouldn't accept) & configuring huffyuv to 
> compress in yuy2 space removed the colour cast. Not too surprising, as 
> this eliminated the one down conversion that was occurring.
>
>   
>>> If no one here knows, any suggestions where I could ask? The issue does 
>>> seem to be specific to mencoder.
>>>
>>>   
>>>       
>> I think you are missing the point... you don't need to do the 
>> intermediate file, avisynth script, or anything like that. Just do it 
>> all in MEncoder. All that other software and extra steps are 
>> unnecessary, and only making the process slower in the long run than 
>> worrying about processing the image on each pass.
>>     
>
> Quite possibly but there are several issues involved here. I'll list the 
> most significant to me first:
>
> It will take me a long time to get to know MEncoder allowing me to get 
> what I want out of it; this job requires a solution now.
>
> I don't like loose ends. Even if I intended switching right now & knew 
> how to get better results with MEncoder, I'd still want to solve my 
> current problem.
>
> Regardless of how many threads I configure MEncoder to use, it still 
> won't run above 25% cpu, strongly suggesting its only using one core 
> (despite having an affinity with all four), so that problem would need 
> solving in any case.
>
>   
I guess the best question at this point is... which MEncoder build are 
you using? Good current builds of MEncoder that support multi-threaded 
encoding in Win32 environments can be found here: 
http://oss.netfarm.it/mplayer-win32.php . Please note that no third 
party builds of MEncoder are supported, at all. So don't take this as an 
endorsement of that particular build - just my friendly advice based on 
my experience.