/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
// This test only works with the GPU backend.
#include "gm.h"
#include "GrBackendSurface.h"
#include "GrContext.h"
#include "GrContextPriv.h"
#include "GrGpu.h"
#include "SkBitmap.h"
#include "SkGradientShader.h"
#include "SkImage.h"
#include "SkTo.h"
static sk_sp<SkColorFilter> yuv_to_rgb_colorfilter() {
static const float kJPEGConversionMatrix[20] = {
1.0f, 0.0f, 1.402f, 0.0f, -180.0f,
1.0f, -0.344136f, -0.714136f, 0.0f, 136.0f,
1.0f, 1.772f, 0.0f, 0.0f, -227.6f,
0.0f, 0.0f, 0.0f, 1.0f, 0.0f
};
return SkColorFilter::MakeMatrixFilterRowMajor255(kJPEGConversionMatrix);
}
namespace skiagm {
class ImageFromYUVTextures : public GpuGM {
public:
ImageFromYUVTextures() {
this->setBGColor(0xFFFFFFFF);
}
protected:
SkString onShortName() override {
return SkString("image_from_yuv_textures");
}
SkISize onISize() override {
return SkISize::Make(kBmpSize + 2 * kPad, 390);
}
void onOnceBeforeDraw() override {
// We create an RGB bitmap and then extract YUV bmps where the U and V bitmaps are
// subsampled by 2 in both dimensions.
SkPaint paint;
constexpr SkColor kColors[] =
{ SK_ColorBLUE, SK_ColorYELLOW, SK_ColorGREEN, SK_ColorWHITE };
paint.setShader(SkGradientShader::MakeRadial(SkPoint::Make(0,0), kBmpSize / 2.f, kColors,
nullptr, SK_ARRAY_COUNT(kColors),
SkShader::kMirror_TileMode));
SkBitmap rgbBmp;
rgbBmp.allocN32Pixels(kBmpSize, kBmpSize, true);
SkCanvas canvas(rgbBmp);
canvas.drawPaint(paint);
SkPMColor* rgbColors = static_cast<SkPMColor*>(rgbBmp.getPixels());
SkImageInfo yinfo = SkImageInfo::MakeA8(kBmpSize, kBmpSize);
fYUVBmps[0].allocPixels(yinfo);
SkImageInfo uinfo = SkImageInfo::MakeA8(kBmpSize / 2, kBmpSize / 2);
fYUVBmps[1].allocPixels(uinfo);
SkImageInfo vinfo = SkImageInfo::MakeA8(kBmpSize / 2, kBmpSize / 2);
fYUVBmps[2].allocPixels(vinfo);
unsigned char* yPixels;
signed char* uvPixels[2];
yPixels = static_cast<unsigned char*>(fYUVBmps[0].getPixels());
uvPixels[0] = static_cast<signed char*>(fYUVBmps[1].getPixels());
uvPixels[1] = static_cast<signed char*>(fYUVBmps[2].getPixels());
// Here we encode using the kJPEG_SkYUVColorSpace (i.e., full-swing Rec 601) even though
// we will draw it with all the supported yuv color spaces when converted back to RGB
for (int i = 0; i < kBmpSize * kBmpSize; ++i) {
yPixels[i] = static_cast<unsigned char>(0.299f * SkGetPackedR32(rgbColors[i]) +
0.587f * SkGetPackedG32(rgbColors[i]) +
0.114f * SkGetPackedB32(rgbColors[i]));
}
for (int j = 0; j < kBmpSize / 2; ++j) {
for (int i = 0; i < kBmpSize / 2; ++i) {
// Average together 4 pixels of RGB.
int rgb[] = { 0, 0, 0 };
for (int y = 0; y < 2; ++y) {
for (int x = 0; x < 2; ++x) {
int rgbIndex = (2 * j + y) * kBmpSize + 2 * i + x;
rgb[0] += SkGetPackedR32(rgbColors[rgbIndex]);
rgb[1] += SkGetPackedG32(rgbColors[rgbIndex]);
rgb[2] += SkGetPackedB32(rgbColors[rgbIndex]);
}
}
for (int c = 0; c < 3; ++c) {
rgb[c] /= 4;
}
int uvIndex = j * kBmpSize / 2 + i;
uvPixels[0][uvIndex] = static_cast<signed char>(
((-38 * rgb[0] - 74 * rgb[1] + 112 * rgb[2] + 128) >> 8) + 128);
uvPixels[1][uvIndex] = static_cast<signed char>(
((112 * rgb[0] - 94 * rgb[1] - 18 * rgb[2] + 128) >> 8) + 128);
}
}
fRGBImage = SkImage::MakeRasterCopy(SkPixmap(rgbBmp.info(), rgbColors, rgbBmp.rowBytes()));
}
void createYUVTextures(GrContext* context, GrBackendTexture yuvTextures[3]) {
GrGpu* gpu = context->priv().getGpu();
if (!gpu) {
return;
}
for (int i = 0; i < 3; ++i) {
SkASSERT(fYUVBmps[i].width() == SkToInt(fYUVBmps[i].rowBytes()));
yuvTextures[i] = gpu->createTestingOnlyBackendTexture(fYUVBmps[i].getPixels(),
fYUVBmps[i].width(),
fYUVBmps[i].height(),
GrColorType::kAlpha_8,
false, GrMipMapped::kNo);
}
context->resetContext();
}
void createResultTexture(GrContext* context, int width, int height,
GrBackendTexture* resultTexture) {
GrGpu* gpu = context->priv().getGpu();
if (!gpu) {
return;
}
*resultTexture = gpu->createTestingOnlyBackendTexture(
nullptr, width, height, GrColorType::kRGBA_8888, true, GrMipMapped::kNo);
context->resetContext();
}
void deleteBackendTextures(GrContext* context, GrBackendTexture textures[], int n) {
if (context->abandoned()) {
return;
}
GrGpu* gpu = context->priv().getGpu();
if (!gpu) {
return;
}
context->flush();
gpu->testingOnly_flushGpuAndSync();
for (int i = 0; i < n; ++i) {
if (textures[i].isValid()) {
gpu->deleteTestingOnlyBackendTexture(textures[i]);
}
}
context->resetContext();
}
void onDraw(GrContext* context, GrRenderTargetContext*, SkCanvas* canvas) override {
// draw the original
SkScalar yOffset = kPad;
canvas->drawImage(fRGBImage.get(), kPad, yOffset);
yOffset += kBmpSize + kPad;
for (int space = kJPEG_SkYUVColorSpace; space <= kLastEnum_SkYUVColorSpace; ++space) {
GrBackendTexture yuvTextures[3];
this->createYUVTextures(context, yuvTextures);
auto image = SkImage::MakeFromYUVTexturesCopy(context,
static_cast<SkYUVColorSpace>(space),
yuvTextures,
kTopLeft_GrSurfaceOrigin);
this->deleteBackendTextures(context, yuvTextures, 3);
SkPaint paint;
if (kIdentity_SkYUVColorSpace == space) {
// The identity color space needs post-processing to appear correct
paint.setColorFilter(yuv_to_rgb_colorfilter());
}
canvas->drawImage(image.get(), kPad, yOffset, &paint);
yOffset += kBmpSize + kPad;
}
for (int space = kJPEG_SkYUVColorSpace; space <= kLastEnum_SkYUVColorSpace; ++space) {
GrBackendTexture yuvTextures[3];
GrBackendTexture resultTexture;
this->createYUVTextures(context, yuvTextures);
this->createResultTexture(
context, yuvTextures[0].width(), yuvTextures[0].height(), &resultTexture);
auto image = SkImage::MakeFromYUVTexturesCopyWithExternalBackend(
context,
static_cast<SkYUVColorSpace>(space),
yuvTextures,
kTopLeft_GrSurfaceOrigin,
resultTexture);
SkPaint paint;
if (kIdentity_SkYUVColorSpace == space) {
// The identity color space needs post-processing to appear correct
paint.setColorFilter(yuv_to_rgb_colorfilter());
}
canvas->drawImage(image.get(), kPad, yOffset, &paint);
yOffset += kBmpSize + kPad;
GrBackendTexture texturesToDelete[4]{
yuvTextures[0],
yuvTextures[1],
yuvTextures[2],
resultTexture,
};
this->deleteBackendTextures(context, texturesToDelete, 4);
}
}
private:
sk_sp<SkImage> fRGBImage;
SkBitmap fYUVBmps[3];
static constexpr SkScalar kPad = 10.0f;
static constexpr int kBmpSize = 32;
typedef GM INHERITED;
};
DEF_GM(return new ImageFromYUVTextures;)
}