[FFmpeg-devel] [PATCH] RoQ video encoder

Michael Niedermayer michaelni
Thu May 31 14:06:20 CEST 2007


On Thu, May 31, 2007 at 12:57:26PM +0200, Michael Niedermayer wrote:
> Hi
> On Wed, May 30, 2007 at 11:42:36PM -0400, Eric Lasota wrote:
> > Hi,
> > 
> > Michael Niedermayer wrote:
> > > roq is a YV12 codec not a YUV 4:4:4 codec AFAIK so this is just wrong
> > 
> > The actual RoQ decoder, the one used in Quake 3, uses RGB.  Check the
> > cl_cin.c file.  Codebooks are converted out of 4:2:0 when they are
> > loaded, and the 8x8 versions are also generated at that point.  This
> > makes sense, as RoQ was created when 16-bit was popular, and and doing
> > tons of copies was probably cheaper than doing colorspace conversion
> > into 16-bit on a full frame on the hardware at the time.
> > 
> > Chroma subsampling is merely done to reduce codebook size.  The
> > authoritative RoQ decoder DOES NOT subsample chroma.  Using 4:4:4 is
> > consequently the correct internal representation.  Ferguson's decoder,
> > the one that FFMPEG was based off of, is incorrect.
> hmm, iam CC-ing this to tim ferguson, lets see what his oppinion is about
> it ...

<timf at csse.monash.edu.au>:<timf at csse.monash.edu.au>:_Recipient_address_rejected:_Mailbox_does_not_exist/Giving_up_on_130.194.1

does anyone have a working email address from him?

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When the tyrant has disposed of foreign enemies by conquest or treaty, and
there is nothing more to fear from them, then he is always stirring up
some war or other, in order that the people may require a leader. -- Plato
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