Adds libSceVideodec2. Access units (Annex B, or length-prefixed rewritten to
Annex B) are decoded by FFmpeg's H.264 decoder into the title's NV12 frame
buffers (256-byte pitch, chroma after the visible luma rows). Decode hands
out at most one picture per call, Flush drains the reordered ones, Reset
clears the decoder; timestamps and attached data travel with the picture.
FFmpeg is found through pkg-config and is optional: without it the decoders
return black pictures. guest_videodec2_tests checks the pictures of an
embedded stream against reference hashes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
boykopovar
Pacuka