// Copyright 2015 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <array>
#include <cstddef>
#include <memory>
#include "common/assert.h"
#include "common/color.h"
#include "common/common_types.h"
#include "common/math_util.h"
#include "common/vector_math.h"
#include "core/hle/service/y2r_u.h"
#include "core/hw/y2r.h"
#include "core/memory.h"
namespace HW {
namespace Y2R {
using namespace Y2R_U;
static const size_t MAX_TILES = 1024 / 8;
static const size_t TILE_SIZE = 8 * 8;
using ImageTile = std::array<u32, TILE_SIZE>;
/// Converts a image strip from the source YUV format into individual 8x8 RGB32 tiles.
static void ConvertYUVToRGB(InputFormat input_format, const u8* input_Y, const u8* input_U,
const u8* input_V, ImageTile output[], unsigned int width,
unsigned int height, const CoefficientSet& coefficients) {
for (unsigned int y = 0; y < height; ++y) {
for (unsigned int x = 0; x < width; ++x) {
s32 Y = 0;
s32 U = 0;
s32 V = 0;
switch (input_format) {
case InputFormat::YUV422_Indiv8:
case InputFormat::YUV422_Indiv16:
Y = input_Y[y * width + x];
U = input_U[(y * width + x) / 2];
V = input_V[(y * width + x) / 2];
break;
case InputFormat::YUV420_Indiv8:
case InputFormat::YUV420_Indiv16:
Y = input_Y[y * width + x];
U = input_U[((y / 2) * width + x) / 2];
V = input_V[((y / 2) * width + x) / 2];
break;
case InputFormat::YUYV422_Interleaved:
Y = input_Y[(y * width + x) * 2];
U = input_Y[(y * width + (x / 2) * 2) * 2 + 1];
V = input_Y[(y * width + (x / 2) * 2) * 2 + 3];
break;
}
// This conversion process is bit-exact with hardware, as far as could be tested.
auto& c = coefficients;
s32 cY = c[0] * Y;
s32 r = cY + c[1] * V;
s32 g = cY - c[3] * U - c[2] * V;
s32 b = cY + c[4] * U;
const s32 rounding_offset = 0x18;
r = (r >> 3) + c[5] + rounding_offset;
g = (g >> 3) + c[6] + rounding_offset;
b = (b >> 3) + c[7] + rounding_offset;
unsigned int tile = x / 8;
unsigned int tile_x = x % 8;
u32* out = &output[tile][y * 8 + tile_x];
using MathUtil::Clamp;
*out = ((u32)Clamp(r >> 5, 0, 0xFF) << 24) | ((u32)Clamp(g >> 5, 0, 0xFF) << 16) |
((u32)Clamp(b >> 5, 0, 0xFF) << 8);
}
}
}
/// Simulates an incoming CDMA transfer. The N parameter is used to automatically convert 16-bit
/// formats to 8-bit.
template <size_t N>
static void ReceiveData(u8* output, ConversionBuffer& buf, size_t amount_of_data) {
const u8* input = Memory::GetPointer(buf.address);
size_t output_unit = buf.transfer_unit / N;
ASSERT(amount_of_data % output_unit == 0);
while (amount_of_data > 0) {
for (size_t i = 0; i < output_unit; ++i) {
output[i] = input[i * N];
}
output += output_unit;
input += buf.transfer_unit + buf.gap;
buf.address += buf.transfer_unit + buf.gap;
buf.image_size -= buf.transfer_unit;
amount_of_data -= output_unit;
}
}
/// Convert intermediate RGB32 format to the final output format while simulating an outgoing CDMA
/// transfer.
static void SendData(const u32* input, ConversionBuffer& buf, int amount_of_data,
OutputFormat output_format, u8 alpha) {
u8* output = Memory::GetPointer(buf.address);
while (amount_of_data > 0) {
u8* unit_end = output + buf.transfer_unit;
while (output < unit_end) {
u32 color = *input++;
Math::Vec4<u8> col_vec{(u8)(color >> 24), (u8)(color >> 16), (u8)(color >> 8), alpha};
switch (output_format) {
case OutputFormat::RGBA8:
Color::EncodeRGBA8(col_vec, output);
output += 4;
break;
case OutputFormat::RGB8:
Color::EncodeRGB8(col_vec, output);
output += 3;
break;
case OutputFormat::RGB5A1:
Color::EncodeRGB5A1(col_vec, output);
output += 2;
break;
case OutputFormat::RGB565:
Color::EncodeRGB565(col_vec, output);
output += 2;
break;
}
amount_of_data -= 1;
}
output += buf.gap;
buf.address += buf.transfer_unit + buf.gap;
buf.image_size -= buf.transfer_unit;
}
}
static const u8 linear_lut[64] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,
44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
};
static const u8 morton_lut[64] = {
0, 1, 4, 5, 16, 17, 20, 21, 2, 3, 6, 7, 18, 19, 22, 23, 8, 9, 12, 13, 24, 25,
28, 29, 10, 11, 14, 15, 26, 27, 30, 31, 32, 33, 36, 37, 48, 49, 52, 53, 34, 35, 38, 39,
50, 51, 54, 55, 40, 41, 44, 45, 56, 57, 60, 61, 42, 43, 46, 47, 58, 59, 62, 63,
};
static void RotateTile0(const ImageTile& input, ImageTile& output, int height,
const u8 out_map[64]) {
for (int i = 0; i < height * 8; ++i) {
output[out_map[i]] = input[i];
}
}
static void RotateTile90(const ImageTile& input, ImageTile& output, int height,
const u8 out_map[64]) {
int out_i = 0;
for (int x = 0; x < 8; ++x) {
for (int y = height - 1; y >= 0; --y) {
output[out_map[out_i++]] = input[y * 8 + x];
}
}
}
static void RotateTile180(const ImageTile& input, ImageTile& output, int height,
const u8 out_map[64]) {
int out_i = 0;
for (int i = height * 8 - 1; i >= 0; --i) {
output[out_map[out_i++]] = input[i];
}
}
static void RotateTile270(const ImageTile& input, ImageTile& output, int height,
const u8 out_map[64]) {
int out_i = 0;
for (int x = 8 - 1; x >= 0; --x) {
for (int y = 0; y < height; ++y) {
output[out_map[out_i++]] = input[y * 8 + x];
}
}
}
static void WriteTileToOutput(u32* output, const ImageTile& tile, int height, int line_stride) {
for (int y = 0; y < height; ++y) {
for (int x = 0; x < 8; ++x) {
output[y * line_stride + x] = tile[y * 8 + x];
}
}
}
/**
* Performs a Y2R colorspace conversion.
*
* The Y2R hardware implements hardware-accelerated YUV to RGB colorspace conversions. It is most
* commonly used for video playback or to display camera input to the screen.
*
* The conversion process is quite configurable, and can be divided in distinct steps. From
* observation, it appears that the hardware buffers a single 8-pixel tall strip of image data
* internally and converts it in one go before writing to the output and loading the next strip.
*
* The steps taken to convert one strip of image data are:
*
* - The hardware receives data via CDMA (http://3dbrew.org/wiki/Corelink_DMA_Engines), which is
* presumably stored in one or more internal buffers. This process can be done in several separate
* transfers, as long as they don't exceed the size of the internal image buffer. This allows
* flexibility in input strides.
* - The input data is decoded into a YUV tuple. Several formats are suported, see the `InputFormat`
* enum.
* - The YUV tuple is converted, using fixed point calculations, to RGB. This step can be configured
* using a set of coefficients to support different colorspace standards. See `CoefficientSet`.
* - The strip can be optionally rotated 90, 180 or 270 degrees. Since each strip is processed
* independently, this notably rotates each *strip*, not the entire image. This means that for 90
* or 270 degree rotations, the output will be in terms of several 8 x height images, and for any
* non-zero rotation the strips will have to be re-arranged so that the parts of the image will
* not be shuffled together. This limitation makes this a feature of somewhat dubious utility. 90
* or 270 degree rotations in images with non-even height don't seem to work properly.
* - The data is converted to the output RGB format. See the `OutputFormat` enum.
* - The data can be output either linearly line-by-line or in the swizzled 8x8 tile format used by
* the PICA. This is decided by the `BlockAlignment` enum. If 8x8 alignment is used, then the
* image must have a height divisible by 8. The image width must always be divisible by 8.
* - The final data is then CDMAed out to main memory and the next image strip is processed. This
* offers the same flexibility as the input stage.
*
* In this implementation, to avoid the combinatorial explosion of parameter combinations, common
* intermediate formats are used and where possible tables or parameters are used instead of
* diverging code paths to keep the amount of branches in check. Some steps are also merged to
* increase efficiency.
*
* Output for all valid settings combinations matches hardware, however output in some edge-cases
* differs:
*
* - `Block8x8` alignment with non-mod8 height produces different garbage patterns on the last
* strip, especially when combined with rotation.
* - Hardware, when using `Linear` alignment with a non-even height and 90 or 270 degree rotation
* produces misaligned output on the last strip. This implmentation produces output with the
* correct "expected" alignment.
*
* Hardware behaves strangely (doesn't fire the completion interrupt, for example) in these cases,
* so they are believed to be invalid configurations anyway.
*/
void PerformConversion(ConversionConfiguration& cvt) {
ASSERT(cvt.input_line_width % 8 == 0);
ASSERT(cvt.block_alignment != BlockAlignment::Block8x8 || cvt.input_lines % 8 == 0);
// Tiles per row
size_t num_tiles = cvt.input_line_width / 8;
ASSERT(num_tiles <= MAX_TILES);
// Buffer used as a CDMA source/target.
std::unique_ptr<u8[]> data_buffer(new u8[cvt.input_line_width * 8 * 4]);
// Intermediate storage for decoded 8x8 image tiles. Always stored as RGB32.
std::unique_ptr<ImageTile[]> tiles(new ImageTile[num_tiles]);
ImageTile tmp_tile;
// LUT used to remap writes to a tile. Used to allow linear or swizzled output without
// requiring two different code paths.
const u8* tile_remap = nullptr;
switch (cvt.block_alignment) {
case BlockAlignment::Linear:
tile_remap = linear_lut;
break;
case BlockAlignment::Block8x8:
tile_remap = morton_lut;
break;
}
for (unsigned int y = 0; y < cvt.input_lines; y += 8) {
unsigned int row_height = std::min(cvt.input_lines - y, 8u);
// Total size in pixels of incoming data required for this strip.
const size_t row_data_size = row_height * cvt.input_line_width;
u8* input_Y = data_buffer.get();
u8* input_U = input_Y + 8 * cvt.input_line_width;
u8* input_V = input_U + 8 * cvt.input_line_width / 2;
switch (cvt.input_format) {
case InputFormat::YUV422_Indiv8:
ReceiveData<1>(input_Y, cvt.src_Y, row_data_size);
ReceiveData<1>(input_U, cvt.src_U, row_data_size / 2);
ReceiveData<1>(input_V, cvt.src_V, row_data_size / 2);
break;
case InputFormat::YUV420_Indiv8:
ReceiveData<1>(input_Y, cvt.src_Y, row_data_size);
ReceiveData<1>(input_U, cvt.src_U, row_data_size / 4);
ReceiveData<1>(input_V, cvt.src_V, row_data_size / 4);
break;
case InputFormat::YUV422_Indiv16:
ReceiveData<2>(input_Y, cvt.src_Y, row_data_size);
ReceiveData<2>(input_U, cvt.src_U, row_data_size / 2);
ReceiveData<2>(input_V, cvt.src_V, row_data_size / 2);
break;
case InputFormat::YUV420_Indiv16:
ReceiveData<2>(input_Y, cvt.src_Y, row_data_size);
ReceiveData<2>(input_U, cvt.src_U, row_data_size / 4);
ReceiveData<2>(input_V, cvt.src_V, row_data_size / 4);
break;
case InputFormat::YUYV422_Interleaved:
input_U = nullptr;
input_V = nullptr;
ReceiveData<1>(input_Y, cvt.src_YUYV, row_data_size * 2);
break;
}
// Note(yuriks): If additional optimization is required, input_format can be moved to a
// template parameter, so that its dispatch can be moved to outside the inner loop.
ConvertYUVToRGB(cvt.input_format, input_Y, input_U, input_V, tiles.get(),
cvt.input_line_width, row_height, cvt.coefficients);
u32* output_buffer = reinterpret_cast<u32*>(data_buffer.get());
for (size_t i = 0; i < num_tiles; ++i) {
int image_strip_width = 0;
int output_stride = 0;
switch (cvt.rotation) {
case Rotation::None:
RotateTile0(tiles[i], tmp_tile, row_height, tile_remap);
image_strip_width = cvt.input_line_width;
output_stride = 8;
break;
case Rotation::Clockwise_90:
RotateTile90(tiles[i], tmp_tile, row_height, tile_remap);
image_strip_width = 8;
output_stride = 8 * row_height;
break;
case Rotation::Clockwise_180:
// For 180 and 270 degree rotations we also invert the order of tiles in the strip,
// since the rotates are done individually on each tile.
RotateTile180(tiles[num_tiles - i - 1], tmp_tile, row_height, tile_remap);
image_strip_width = cvt.input_line_width;
output_stride = 8;
break;
case Rotation::Clockwise_270:
RotateTile270(tiles[num_tiles - i - 1], tmp_tile, row_height, tile_remap);
image_strip_width = 8;
output_stride = 8 * row_height;
break;
}
switch (cvt.block_alignment) {
case BlockAlignment::Linear:
WriteTileToOutput(output_buffer, tmp_tile, row_height, image_strip_width);
output_buffer += output_stride;
break;
case BlockAlignment::Block8x8:
WriteTileToOutput(output_buffer, tmp_tile, 8, 8);
output_buffer += TILE_SIZE;
break;
}
}
// Note(yuriks): If additional optimization is required, output_format can be moved to a
// template parameter, so that its dispatch can be moved to outside the inner loop.
SendData(reinterpret_cast<u32*>(data_buffer.get()), cvt.dst, (int)row_data_size,
cvt.output_format, (u8)cvt.alpha);
}
}
}
}
