sceMpegBasePESpacketCopy used to gather each DMA into a buffer filed under the
address of its first block, and sceVideocodecDecode looked one up by the address
it was handed. That works only while an access unit arrives in a single call. It
doesn't: mpeg.prx routinely DMAs one in several pieces at consecutive addresses,
and the table then kept whichever piece happened to start where the decode later
asked, and dropped the rest.
So the DMA now writes each block at the address it names. The Media Engine's own
memory moves to its real addresses - low ones, which mpeg.prx bounds-checks
against 0x3FFFFF - and pieces written at consecutive addresses end up
consecutive, which is all this ever needed. Our own allocations move to the top
half, away from the addresses mpeg.prx picks for itself.
That memory is the ME's, not the Allegrex's, and the two are separate address
spaces: on hardware only the ME reaches it, so here it is a buffer of our own
that nothing emulated can address. It gets its own MEIsValidRange and
MEGetPointerRange rather than borrowing Memory::, which answers for the
Allegrex's memory and has nothing to say about this one.
An address only means something together with the space it came from, and
mpeg.prx hands over bare integers. The three places that have to work it out
from the value now ask the ME first, where they used to ask Memory:: first and
so read every address as the CPU's. It separates the addresses these callers
actually pass (ME memory well down in the first megabyte, PSP RAM at 0x08000000
and up), but that's those callers rather than a rule.
Savestates from before this carry the old packet table; it's read and dropped,
since the Media Engine's memory is saved and that's where the payloads live now.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
__MpegBaseInit was called by __MpegInit rather than by __KernelInit, and
__MpegBaseShutdown had just been added the same way. Every other module is
started and stopped directly by the kernel - __MpegBaseDoState already was -
so do the same here and let sceMpeg.cpp mind only its own state.
The order is unchanged: __MpegBaseInit ran first inside __MpegInit and now sits
just before it, __MpegBaseShutdown ran last and now sits just after.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
__MpegBaseShutdown, hanging off __MpegShutdown the way __MpegBaseInit hangs off
__MpegInit, so the de-tiling scratch and the swscale context go back when the
game stops rather than only when the next one starts. Between them they are a
few hundred kilobytes that a game which played one video early on has no further
use for.
Also name the swscale flags rather than passing SWS_POINT inline, and say next
to it what the choice actually decides - with equal sizes in and out it is only
how chroma gets to full resolution, and SWS_BILINEAR (what the HLE uses) is a
one-line swap. Worth a real option one day; not adding one now.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The planes the de-tiling produces are already the YUV420P swscale wants, and our
sceMpeg HLE converts the same frames the same way, so the pixel formats and the
studio-range setup come straight from MediaEngine::getSwsFormat. It is 3-4x
quicker than going a pixel at a time: 0.37-0.44ms a frame becomes 0.09-0.12ms,
which is the whole reason sceMpegBaseCscAvc was at the top of a profile.
Chroma is upsampled with SWS_POINT rather than the HLE's SWS_BILINEAR, since
replicating is what the scalar path does and, being a fixed-function block,
almost certainly what the hardware does.
It is not bit-identical - swscale rounds its own way. TestMpegCsc measures the
gap per channel rather than per byte, so the number means something for a packed
16-bit pixel: worst 1 step of 31 for 5650 and 5551, 2 of 15 for 4444, 3 of 255
for 8888, with means around a fifth of a step. The scalar path stays as what the
longhand reference is checked against, and takes anything swscale won't - an odd
range origin, or a build without ffmpeg.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The colour conversion was writing alpha fully set - 0xFF000000, or the top bit
for 5551 - where the hardware writes zero. Our sceMpeg HLE already masks it off
and names Sword Art Online as a game that depends on it: it doesn't clear the
alpha in the buffer it hands over, and expects the video not to set it. The two
paths now agree.
The de-tiling ahead of it becomes UntileYCbCr, taking the eight buffers already
resolved, so it can be measured and compared against the original longhand
version in TestMpegCsc. Its planes move to scratch that persists between calls -
a movie converts one frame per displayed frame, and this was allocating and
clearing about 200KB every time - and the per-pixel bounds checks in the chroma
loop, which only depend on the group of eight, are hoisted out of it.
That last part is worth 2529 -> 3201 MPix/s, but the point of measuring was to
find out whether it mattered, and it doesn't much: de-tiling is 0.04ms of a
frame against the conversion's 0.4ms. The conversion is where the time is.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
sceMpegBaseCscAvc is the top of a profile during video playback, so the loop
that does the work becomes MpegCscRange - a pure function with the HLE plumbing
left behind - and TestMpegCsc measures and checks it.
The measuring half reports megapixels per second for a 480x272 frame in each of
the four pixel formats. The checking half compares against the conversion
written out longhand, over whole frames and over partial ranges with odd offsets
and sizes, plus one-pixel, one-row and one-column ranges and one that reaches
the far edge of the frame. Those are the cases an optimized version gets wrong:
chroma is half resolution, so an odd left edge starts mid-sample, and anything
handling two pixels at a time has to deal with the leftover. The destination is
padded and prefilled, so writing outside the range fails too.
This is only the move - the loop is the same one, so the numbers it gives are
the baseline to improve on. On a Snapdragon X Elite it runs at about 300 MPix/s,
0.44ms for a frame.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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) <noreply@anthropic.com>
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) <noreply@anthropic.com>
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) <noreply@anthropic.com>
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) <noreply@anthropic.com>
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) <noreply@anthropic.com>
