[MPlayer-dev-eng] Mpeg2 Interlaced

[Gábor Lénárt]

On Tue, Sep 25, 2001 at 11:09:55PM +0200, Arpi wrote:
> Hi,
> 
> > Here is my second patch about Mpeg2 interlaced. The
> > previus one hasn't been applyed so i this one containd
> > it. That does patch does.
> > It draws Frame or second(bottom) Filed (as pp does). 
> > Now it report correctly is_frame_done, and
> > decode_vid.c flips only if the frame (or 2 field) have
> > been drawn. This reduce CPU usage by 2-3 times. It may
> > also help on none Interlaced mpeg2 streems. 
> > There is also a problem with synchronization, if mpeg2
> > is 25 fps you must -fps 50. There must be more drastic
> > changes to fix that.
> 
> Sorry, I can't apply it...
> You've removed the slice-copy code.
> It means about 5% speed loss on celeron-600.

Well :) I'm not in charge of knowledge on mpeg details but I can say that
we should not make modifications on mplayer which makes decoding slower
even with 0.1% ... (imagine about hunderds of "feature extension patch"
for - let's say - two years of development. if each slows mplayer by only
a very little, it makes quite slowdown after two years ...).
And don't forget the other case either: don't make modifications which
is great for one thing, but makes broken or slower another ...

OK, this was only something development philosophy and not technial
detailed mail, as you can see.

- Gabor

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