[MPlayer-users] Makeing a video processable by an embedded system

[Reimar Döffinger]

On Sat, Aug 18, 2012 at 11:36:01PM +0200, Alexander Roalter wrote:
> On 08/18/2012 09:52 PM, Ron Johnson wrote:
> >On 08/18/2012 01:59 PM, Reimar Döffinger wrote:
> >>On Sat, Aug 18, 2012 at 07:30:35PM +0200, meino.cramer at gmx.de wrote:
> >
> >Would it also be useful for him to transcode the video down to 600x480
> >(which is the same aspect ratio as 720x576)?
> >
> I'm not sure if that's correct. MPEG ratio 3 (720x576) has
> non-square pixels and gets resized (with square pixels) to 768x576.
> So 640x480 would be the correct aspect aspect ratio, where it could
> play with no scaling, simply adding black pillars on the side to fit
> it in 800x480.

That's all well and possible comments, but it is also getting ahead of
things.
Depending on what exactly goes on it might not make any difference
e.g. because there is no implementation of a fast colorspace conversion
in that case, then it will be just as slow no matter if scaling happens
or not.
Also scaling can be sped up with the -sws option to select e.g. nearest
neighbour.
But without assembler optimizations it most likely will still be badly slow,
in which case all those suggestions might be just detail optimizations that
will not help.
We don't even know if it's a matter getting just 2% faster or rather 10 times
faster and the answer for one will usually be nonsense for the other
case.