sceVideoOutRegisterBuffers2 threw "DCC presentation is not implemented"
for category 1 (DCC-compressed) buffers, which PPSA26344 registers. Such
a buffer now needs DCC metadata and the tiled layout, and dcc_control may
only use the CB_DCC_CONTROL block layout bits 0x10026c.
At a flip the keys are read behind their recorded writers, one byte per
256 bytes as in the driver's DCC model. Uncompressed keys present the
stored texels as before; a uniform clear code presents its color with a
GPU clear of the scaler's source image; a pending storage image is used
when it serves the keys. Mixed or unreadable keys, clear codes the
display format has no DCC encoding for, register-clear keys over a
pending image and a clear color wider than 32 bits throw. Buffers
without DCC take the old path.