[PATCH v2 3/5] drm/rockchip: vop: support plane scale

[Mark yao]

On 2015年07月03日 17:58, Tomasz Figa wrote:
>>> >>Aren't the scl_modes for CbCr planes always the same as for Y plane?
>> >
>> >
>> >No, such as src(1920 x 1080) -> dst(1280x800), yuv format is NV12.
>> >so Y plane horizontal and vertical is scale down.
>> >
>> >but src_w = 1920 / 2 = 960 < 1280
>> >       src_h = 1080 / 2 = 540 < 800.
>> >
>> >So Cbcr horizontal and vertical is scale up.
> Sorry, I don't follow.
>
> If we scale down Y plane in NV12 from 1920x1080 to 1280x800, then
> original CbCr plane will be 960x540 and destination CbCr plane will be
> 640x400 (because CbCr plane of NV12 is subsampled 2x2, which is half
> the width and half the height of Y plane), so both planes are being
> scaled down.
>
destination CbCr plane is 1280x800, destination can't be subsample.

-- 
Ｍark