- // Adds an YCbCr output. Note that you can only have one Y'CbCr output.
- // Currently, only 4:4:4 output is supported, so chroma_subsampling_x
- // and chroma_subsampling_y must both be 1.
+ // Adds an YCbCr output. Note that you can only have at most two Y'CbCr
+ // outputs, and they must have the same <ycbcr_format>.
+ // (This limitation may be lifted in the future, to allow e.g. simultaneous
+ // 8- and 10-bit output. Currently, multiple Y'CbCr outputs are only
+ // useful in some very limited circumstances, like if one texture goes
+ // to some place you cannot easily read from later.)