This is what sceMpegAvcCopyYCbCr is built on, and a game that wants the raw
YCbCr rather than letting sceMpegbase convert to RGB uses it and nothing else.
mpeg.prx builds the descriptor on its own stack and avcodec.prx reads it back at
0x800015c4. Dimensions in pixels at 0x00/0x04, the eight frame buffers from 0x0c
but ordered 0,2,4,6 then 1,3,5,7, and from 0x2c the destination Y with Cb and Cr
following it contiguously - ordinary planar YUV420. Checked against what the
game passes: the eight addresses are exactly the buffers we handed out, and the
three destinations are spaced width*height and width*height/4 apart.
Un-tiling is the same operation the colour conversion already does, so that
moves out of sceMpegbase.cpp as ReadTiledYCbCr rather than being written twice.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
The output pixel mode decides both the colour packing and the bytes per pixel of
the conversion, and a game sets it once per movie rather than per frame - so a
state resumed mid-movie converted at the default until the next
sceMpegBaseCscInit, which may never come. The gathered PES payloads go in too,
since a state can land between the copy and the decode that consumes it.
The section is optional (minimum version 0), so states written before it still
load.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Decode looked its context up with operator[], so a game that never opened one
would still get an entry and a decoder, and only Delete ever removes those.
Require the context to exist instead.
The gathered PES payloads were likewise kept for the whole boot, so the first
decode of a movie could be handed the last packet of the previous one if the
address came round again. Hand each payload out once.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Add flash0:/kd/mpeg.prx to the sceUtility module swap, hung off av_mpegbase,
so it loads when DisableHLEFlags::sceMpeg is set. Games that ship their own
sceMpeg_library on the disc never get here and just use theirs.
The piece that was missing to make it work: the access unit address mpeg.prx
passes to sceVideocodecDecode is in Media Engine space, which we can't read.
On hardware sceMpegBasePESpacketCopy DMA'd the payload there first. That copy
is ours, so it now gathers the blocks and sceVideocodec decodes from those,
falling back to main memory for any caller that points at it directly. The
gather is keyed by destination, because that call carries the audio payload
too - video to an ME address, audio to main memory - and handing an ATRAC
packet to the H.264 decoder gets you nothing.
With that, video/mpeg/basic gets a 144x80 frame out of real Sony code driving
our sceVideocodec through ffmpeg. The test still fails overall, as it did
before this branch - it is in tests_next.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Five of the six functions in this module were registered as nullptr, so any
caller reaching them got nothing. mpeg.prx needs all of them, and this is the
first of the pieces required before the real module can run in place of our
sceMpeg HLE.
The module gets its own file at the same time. It was a tail of sceMpeg.cpp,
which is long enough already, and everything below is new code for it.
sceMpegBaseCscAvc and sceMpegBaseCscAvcRange convert the ME's decoded output to
RGB. The 48-byte descriptor holds the frame size in macroblocks at 0x10 and
0x14 - it appears at 0x00/0x04 too, but scaled differently depending on which
path built it, so the second pair is the one every caller agrees on - and the
four luma buffers at 0x20. What they point at is not planar: luma arrives as
16-pixel-wide vertical strips alternating between buffers on every other line,
and chroma as Cb/Cr pairs interleaved across four more. All eight are untangled
into planes once per frame before converting, which keeps the pixel loop
readable.
sceMpegBaseCscInit carries the default buffer width for callers that pass zero.
sceMpegBaseCscSetPixelMode (0x0530BE4E - the official name isn't known) carries
the output format, in mpegbase's own numbering rather than the GE's: mpeg.prx
gets it by indexing a table of {1, 2, 3, 0} with the pixel mode the game gave
sceMpegAvcDecodeMode, making 0 ABGR8888 and 2 ABGR5551. Read as a GE mode it
turned Thrillville's black into blue.
sceMpegBaseYCrCbCopy copies the descriptor but not the buffers it points at,
and says so in its log - nothing seen so far needs more, and inventing the
buffer copy without something to test it against seemed worse than a note.
Behaviour is cross-checked against JPCSP, which implements all of these.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>