What is the algorithm used for up and down chroma sampling on a Silicon Graphics 320 and 540?
On chroma upsample in video in, the odd pixels’ chroma are averaged from its nearest 2 even pixels, except for the last odd pixel, which is replicated from its nearest even pixel. On chroma downsample in video out, the even pixels’ chroma consists of 1/4 of each if its nearest odd pixels and 1/2 of its own chroma value.