[MEncoder-users] improving performance - general questions

[Reimar Döffinger]

On Sat, Aug 18, 2012 at 09:44:23PM +0200, Reimar Döffinger wrote:
> On Thu, Aug 16, 2012 at 05:00:49PM -0300, Rossana Guerra wrote:
> > Hi every one, I have only one processor and it tooks time to add subtitles.
> 
> Rendering subtitles (at least the plain white/one-colored ones) should
> take almost no CPU.
> 
> > So some questions comes to my mind.
> > I apprecitate any suggestions to improve this task: theading?, enable GPU.
> > Is better with a good graphic card?.
> 
> We need more details, in particular including the MPlayer output, to
> answer that.
> -vo gl can use the GPU to render the subtitles, but that is not
> necessarily faster, it can be slower.

I missed this was on the mencoder list.
So I suspect the issue is having to transcode to add subtitles.
In that case it depends on what output format you need, what
files size constraints you have, what resolution you want etc.
For example with the MPEG-4 ASP encoder if you just set a qscale of 2
and mbd 0 you should be able to reach around 100 fps (ca. 4x realtime)
encode speed for DVD resolution even with a single-core CPU.
Threading doesn't help if you have only one core.