[MPlayer-dev-eng] Re: ccache

[Michael Niedermayer]

Hi

On Monday 06 January 2003 01:07, Tobias Diedrich wrote:
> After reading the explanation I have to correct myself:
>
> Tobias Diedrich wrote:
> > 3)
> > The "color interlacing" can happen if an YUV411 Signal is converted to
> > RGB or vice versa. You have to use different algorithms for interlaced
> > and progressive material. For progressive material the first UV-Line
> > contains color information for Y-Line 1+2, for interlaced material it is
> > for Y-Line 1+3.
> >
> > 6)
> > PAL vs. NTSC:
> > PAL has a slightly higher luma resolution, but a halfed chroma
> > resolution because of the Phase Alternating Line Color Encoding.
> > IIRC NTSC is information wise comparable to YUV422 while PAL carries
> > only as much information as an YUV411 picture...
>
> s/YUV411/YUV420/
>
> For a 4x4 pixel matrix the encodings should be:
[...]
> YUV420:
>    0    1    2    3
> 0 YUV  Y    YUV  Y
>
> 1 Y    Y    Y    Y
>
> 2 YUV  Y    YUV  Y
>
> 3 Y    Y    Y    Y
hmm, looks too clean & simple, why not
 MPEG1 YUV420:
   0    1    2    3
 0 Y    Y    Y    Y
     UV        UV
 1 Y    Y    Y    Y

 2 Y    Y    Y    Y
     UV        UV
 3 Y    Y    Y    Y
 MPEG2/4 YUV420:
   0    1    2    3
 0 Y    Y    Y    Y
   UV        UV
 1 Y    Y    Y    Y

 2 Y    Y    Y    Y
   UV        UV
 3 Y    Y    Y    Y

and now the temporal structure for the interlaced variant
      Time
       ->
height  Y 
      | C
      v    Y
         
        Y
           C
           Y

        Y
        C
           Y

        Y
           C

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

[...]

Michael