[FFmpeg-devel] [PATCH 36/36] avcodec/mpegvideo_enc: Remove dead code at compile time

Michael Niedermayer michael at niedermayer.cc
Fri Dec 24 20:36:40 EET 2021


On Fri, Dec 24, 2021 at 07:30:11PM +0100, Andreas Rheinhardt wrote:
> Michael Niedermayer:
> > On Fri, Dec 24, 2021 at 04:23:32AM +0100, Andreas Rheinhardt wrote:
> >> There are no encoders for interlaced dct that support 4:4:4.
> > 
> > i dont remember why its not supported but
> > why not add 4:4:4 interlaced dct support ?
> > 
> > just thinking as you already work on the code, that would seem to me
> > the "more interresting" route than to optimize that out
> > 
> > nothing againt this patch of course, thats fine too
> > 
> > thx
> > [...]
> > 
> 
> There are two encoders that support interlaced DCT: mpeg2video and
> mpeg4. Our encoder for the former supports 420 and 422; the format also
> allows 444. I don't really know how much is missing for supporting this
> (it's probably more than just hardcoding a third chroma format in
> ff_mpeg1_encode_mb()). And honestly, I don't really want to reread the
> mpeg-2 spec to find out, because it is nearly 2022 and MPEG-2 is
> obsolete and legacy.

our decoder should support 444 i dont remember anything special
but i agree, it makes little sense for a old format unless one
enjoys doing it

thx


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Those who are too smart to engage in politics are punished by being
governed by those who are dumber. -- Plato 
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