[MPlayer-dev-eng] Re: ccache

[Arpi]

Hi,

> 
> no, iam not joking, this is exactly what the mpeg4 & mpeg2 std says for 
> interlaced YCbCr 420

btw, how are these handled in mplayer? i guess they aren't.
at least i can't imagine how does postproc or swscale or even teh vo
drivers know if that YV12 frame comes from jpg/mpeg1, mpeg2 (frame or fields)
or mpeg4? since they have different chroma rules...

also, what about the 4x4 subsampled YUV 4:1:0 (YVU9) used in indeo & sorenson?
both rules (c't's and the pdf's) description says that 4:1:0 means 4x2
pixels subsampling (4 Y 1 UV in even lines, and no UV in the odd lines)
but it's really 4x4 (UV only in every 4th lines). and where are UV pixels
sampled there?  at least i can differenec displaying lwores YVU9 using ati
mach64's hw YVU9 scaler and swscaler (swscaler looks much better :)),
ati's one shows chroma a bit shifted.

and anyway, what does the whole chroma subsamplin means ?
there are 4 pixels:
P1 P2
P3 P4

is U the average of P1..P4's U values, is the average of P1 & P3's average,
is P1's U or what?


A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu