[MPlayer-dev-eng] help request: YUV fourcc internals

[Arpi]

Hi,

> As I've found (looking at radeon sources from X11 and gatos stuffs):
> YUY2 is flat format - it has only one image surface with interlaved
> YUYV components (and indeed it's VYUY422 format).
yes, YUY2 and UYVY are packed (interleaved) YUV 4:2:2 formats

> Well, but IYUV, YV12, I420 are complex formats and consist from 3 parts:
> 
> +------------+
> |            |
> |     P1     |
> |            |
> +------------+
> | P2  |  P3  |
> +------------+
yes.

> As I've found only difference between I420 and YV12 it's swapped P2 and P3
yes.

> parts. And as I understand: IYUV === YUV12, isn't?
no. IYUV == I420 == swappedUV(YV12)

> But what is difference between YUV12 and YV12?
YV12 is the fourcc of YUV12. there is no format called YUV12 in this world.
in tech stuff call it planar 4:2:0, the codecs call it YV12

> >From name it's understandable that YV12 lacks U-component,
> then what is instead?
no.

> P.S.: IMHO it would be better to add such info into main/DOCS/tech/fourcc.txt
> same as describe - what codec are able to produce rare outputs.
> (Currently I'm interesting with I420, YUV12, YVYU422, YUV09, and many other
> from img_format.h)
ok. later. or do it. :)


A'rpi / Astral & ESP-team

--
mailto:arpi at thot.banki.hu
http://esp-team.scene.hu