On 2015?07?03? 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. -- ?ark
