j2k-transcode
JPEG to J2K/HTJ2K transcode crate for J2K.
The crate owns CPU transcode algorithms and shared accelerator hooks. CUDA and Metal acceleration live in adapter crates. Unsupported source classes and unsupported transcode modes return explicit errors.
Resident handoff descriptors such as ResidentJpegDctGrid,
ResidentDwtSubband, and ResidentCodestreamBuffer provide validated metadata
contracts for backend adapters that keep transcode stages in device memory.