static bool skip_src_rows_tile(jpeg_decompress_struct* cinfo,
huffman_index *index, void* buffer,
int count) {
for (int i = 0; i < count; i++) {
JSAMPLE* rowptr = (JSAMPLE*)buffer;
int row_count = jpeg_read_tile_scanline(cinfo, index, &rowptr);
if (row_count != 1) {
return false;
}
}
return true;
}
bool SkJPEGImageDecoder::onDecodeRegion(SkBitmap* bm, SkIRect region) {
if (index == NULL) {
return false;
}
int startX = region.fLeft;
int startY = region.fTop;
int width = region.width();
int height = region.height();
jpeg_decompress_struct *cinfo = index->cinfo;
SkAutoMalloc srcStorage;
skjpeg_error_mgr sk_err;
cinfo->err = jpeg_std_error(&sk_err);
sk_err.error_exit = skjpeg_error_exit;
if (setjmp(sk_err.fJmpBuf)) {
return false;
}
int requestedSampleSize = this->getSampleSize();
cinfo->scale_denom = requestedSampleSize;
if (this->getPreferQualityOverSpeed()) {
cinfo->dct_method = JDCT_ISLOW;
} else {
cinfo->dct_method = JDCT_IFAST;
}
SkBitmap::Config config = this->getPrefConfig(k32Bit_SrcDepth, false);
if (config != SkBitmap::kARGB_8888_Config &&
config != SkBitmap::kARGB_4444_Config &&
config != SkBitmap::kRGB_565_Config) {
config = SkBitmap::kARGB_8888_Config;
}
/* default format is RGB */
cinfo->out_color_space = JCS_RGB;
#ifdef ANDROID_RGB
cinfo->dither_mode = JDITHER_NONE;
if (config == SkBitmap::kARGB_8888_Config) {
cinfo->out_color_space = JCS_RGBA_8888;
} else if (config == SkBitmap::kRGB_565_Config) {
cinfo->out_color_space = JCS_RGB_565;
if (this->getDitherImage()) {
cinfo->dither_mode = JDITHER_ORDERED;
}
}
#endif
int oriStartX = startX;
int oriStartY = startY;
int oriWidth = width;
int oriHeight = height;
jpeg_init_read_tile_scanline(cinfo, index->index,
&startX, &startY, &width, &height);
int skiaSampleSize = recompute_sampleSize(requestedSampleSize, *cinfo);
int actualSampleSize = skiaSampleSize * (DCTSIZE / cinfo->min_DCT_scaled_size);
SkBitmap *bitmap = new SkBitmap;
SkAutoTDelete<SkBitmap> adb(bitmap);
#ifdef ANDROID_RGB
/* short-circuit the SkScaledBitmapSampler when possible, as this gives
a significant performance boost.
*/
if (skiaSampleSize == 1 &&
((config == SkBitmap::kARGB_8888_Config &&
cinfo->out_color_space == JCS_RGBA_8888) ||
(config == SkBitmap::kRGB_565_Config &&
cinfo->out_color_space == JCS_RGB_565)))
{
bitmap->setConfig(config, cinfo->output_width, height);
bitmap->setIsOpaque(true);
if (!this->allocPixelRef(bitmap, NULL)) {
return return_false(*cinfo, *bitmap, "allocPixelRef");
}
SkAutoLockPixels alp(*bitmap);
JSAMPLE* rowptr = (JSAMPLE*)bitmap->getPixels();
INT32 const bpr = bitmap->rowBytes();
int row_total_count = 0;
while (row_total_count < height) {
int row_count = jpeg_read_tile_scanline(cinfo,
index->index, &rowptr);
// if row_count == 0, then we didn't get a scanline, so abort.
// if we supported partial images, we might return true in this case
if (0 == row_count) {
return return_false(*cinfo, *bitmap, "read_scanlines");
}
if (this->shouldCancelDecode()) {
return return_false(*cinfo, *bitmap, "shouldCancelDecode");
}
row_total_count += row_count;
rowptr += bpr;
}
cropBitmap(bm, bitmap, actualSampleSize, oriStartX, oriStartY,
oriWidth, oriHeight, startX, startY);
return true;
}
#endif
// check for supported formats
SkScaledBitmapSampler::SrcConfig sc;
if (3 == cinfo->out_color_components && JCS_RGB == cinfo->out_color_space) {
sc = SkScaledBitmapSampler::kRGB;
#ifdef ANDROID_RGB
} else if (JCS_RGBA_8888 == cinfo->out_color_space) {
sc = SkScaledBitmapSampler::kRGBX;
} else if (JCS_RGB_565 == cinfo->out_color_space) {
sc = SkScaledBitmapSampler::kRGB_565;
#endif
} else if (1 == cinfo->out_color_components &&
JCS_GRAYSCALE == cinfo->out_color_space) {
sc = SkScaledBitmapSampler::kGray;
} else {
return return_false(*cinfo, *bm, "jpeg colorspace");
}
SkScaledBitmapSampler sampler(width, height, skiaSampleSize);
bitmap->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight());
bitmap->setIsOpaque(true);
if (!this->allocPixelRef(bitmap, NULL)) {
return return_false(*cinfo, *bitmap, "allocPixelRef");
}
SkAutoLockPixels alp(*bitmap);
if (!sampler.begin(bitmap, sc, this->getDitherImage())) {
return return_false(*cinfo, *bitmap, "sampler.begin");
}
uint8_t* srcRow = (uint8_t*)srcStorage.reset(width * 4);
// Possibly skip initial rows [sampler.srcY0]
if (!skip_src_rows_tile(cinfo, index->index, srcRow, sampler.srcY0())) {
return return_false(*cinfo, *bitmap, "skip rows");
}
// now loop through scanlines until y == bitmap->height() - 1
for (int y = 0;; y++) {
JSAMPLE* rowptr = (JSAMPLE*)srcRow;
int row_count = jpeg_read_tile_scanline(cinfo, index->index, &rowptr);
if (0 == row_count) {
return return_false(*cinfo, *bitmap, "read_scanlines");
}
if (this->shouldCancelDecode()) {
return return_false(*cinfo, *bitmap, "shouldCancelDecode");
}
sampler.next(srcRow);
if (bitmap->height() - 1 == y) {
// we're done
break;
}
if (!skip_src_rows_tile(cinfo, index->index, srcRow,
sampler.srcDY() - 1)) {
return return_false(*cinfo, *bitmap, "skip rows");
}
}
cropBitmap(bm, bitmap, actualSampleSize, oriStartX, oriStartY,
oriWidth, oriHeight, startX, startY);
return true;
}
bool SkJPEGImageDecoder::onDecodeRegion(SkBitmap* bm, SkIRect region) {
if (index == NULL) {
return false;
}
jpeg_decompress_struct *cinfo = index->cinfo;
SkIRect rect = SkIRect::MakeWH(this->imageWidth, this->imageHeight);
if (!rect.intersect(region)) {
// If the requested region is entirely outsides the image, just
// returns false
return false;
}
SkAutoMalloc srcStorage;
skjpeg_error_mgr sk_err;
cinfo->err = jpeg_std_error(&sk_err);
sk_err.error_exit = skjpeg_error_exit;
if (setjmp(sk_err.fJmpBuf)) {
return false;
}
int requestedSampleSize = this->getSampleSize();
cinfo->scale_denom = requestedSampleSize;
if (this->getPreferQualityOverSpeed()) {
cinfo->dct_method = JDCT_ISLOW;
} else {
cinfo->dct_method = JDCT_IFAST;
}
SkBitmap::Config config = this->getPrefConfig(k32Bit_SrcDepth, false);
if (config != SkBitmap::kARGB_8888_Config &&
config != SkBitmap::kARGB_4444_Config &&
config != SkBitmap::kRGB_565_Config) {
config = SkBitmap::kARGB_8888_Config;
}
/* default format is RGB */
cinfo->out_color_space = JCS_RGB;
#ifdef ANDROID_RGB
cinfo->dither_mode = JDITHER_NONE;
if (config == SkBitmap::kARGB_8888_Config) {
cinfo->out_color_space = JCS_RGBA_8888;
} else if (config == SkBitmap::kRGB_565_Config) {
cinfo->out_color_space = JCS_RGB_565;
if (this->getDitherImage()) {
cinfo->dither_mode = JDITHER_ORDERED;
}
}
#endif
int startX = rect.fLeft;
int startY = rect.fTop;
int width = rect.width();
int height = rect.height();
jpeg_init_read_tile_scanline(cinfo, index->index,
&startX, &startY, &width, &height);
int skiaSampleSize = recompute_sampleSize(requestedSampleSize, *cinfo);
int actualSampleSize = skiaSampleSize * (DCTSIZE / cinfo->min_DCT_scaled_size);
SkBitmap *bitmap = new SkBitmap;
SkAutoTDelete<SkBitmap> adb(bitmap);
#ifdef ANDROID_RGB
/* short-circuit the SkScaledBitmapSampler when possible, as this gives
a significant performance boost.
*/
if (skiaSampleSize == 1 &&
((config == SkBitmap::kARGB_8888_Config &&
cinfo->out_color_space == JCS_RGBA_8888) ||
(config == SkBitmap::kRGB_565_Config &&
cinfo->out_color_space == JCS_RGB_565)))
{
bitmap->setConfig(config, cinfo->output_width, height);
bitmap->setIsOpaque(true);
// Check ahead of time if the swap(dest, src) is possible or not.
// If yes, then we will stick to AllocPixelRef since it's cheaper
// with the swap happening. If no, then we will use alloc to allocate
// pixels to prevent garbage collection.
//
// Not using a recycled-bitmap and the output rect is same as the
// decoded region.
int w = rect.width() / actualSampleSize;
int h = rect.height() / actualSampleSize;
bool swapOnly = (rect == region) && bm->isNull() &&
(w == bitmap->width()) && (h == bitmap->height()) &&
((startX - rect.x()) / actualSampleSize == 0) &&
((startY - rect.y()) / actualSampleSize == 0);
if (swapOnly) {
if (!this->allocPixelRef(bitmap, NULL)) {
return return_false(*cinfo, *bitmap, "allocPixelRef");
}
} else {
if (!bitmap->allocPixels()) {
return return_false(*cinfo, *bitmap, "allocPixels");
}
}
SkAutoLockPixels alp(*bitmap);
JSAMPLE* rowptr = (JSAMPLE*)bitmap->getPixels();
INT32 const bpr = bitmap->rowBytes();
int row_total_count = 0;
while (row_total_count < height) {
int row_count = jpeg_read_tile_scanline(cinfo,
index->index, &rowptr);
// if row_count == 0, then we didn't get a scanline, so abort.
// if we supported partial images, we might return true in this case
if (0 == row_count) {
return return_false(*cinfo, *bitmap, "read_scanlines");
}
if (this->shouldCancelDecode()) {
return return_false(*cinfo, *bitmap, "shouldCancelDecode");
}
row_total_count += row_count;
rowptr += bpr;
}
if (swapOnly) {
bm->swap(*bitmap);
} else {
cropBitmap(bm, bitmap, actualSampleSize, region.x(), region.y(),
region.width(), region.height(), startX, startY);
}
return true;
}
#endif
// check for supported formats
SkScaledBitmapSampler::SrcConfig sc;
if (3 == cinfo->out_color_components && JCS_RGB == cinfo->out_color_space) {
sc = SkScaledBitmapSampler::kRGB;
#ifdef ANDROID_RGB
} else if (JCS_RGBA_8888 == cinfo->out_color_space) {
sc = SkScaledBitmapSampler::kRGBX;
} else if (JCS_RGB_565 == cinfo->out_color_space) {
sc = SkScaledBitmapSampler::kRGB_565;
#endif
} else if (1 == cinfo->out_color_components &&
JCS_GRAYSCALE == cinfo->out_color_space) {
sc = SkScaledBitmapSampler::kGray;
} else {
return return_false(*cinfo, *bm, "jpeg colorspace");
}
SkScaledBitmapSampler sampler(width, height, skiaSampleSize);
bitmap->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight());
bitmap->setIsOpaque(true);
// Check ahead of time if the swap(dest, src) is possible or not.
// If yes, then we will stick to AllocPixelRef since it's cheaper with the
// swap happening. If no, then we will use alloc to allocate pixels to
// prevent garbage collection.
int w = rect.width() / actualSampleSize;
int h = rect.height() / actualSampleSize;
bool swapOnly = (rect == region) && bm->isNull() &&
(w == bitmap->width()) && (h == bitmap->height()) &&
((startX - rect.x()) / actualSampleSize == 0) &&
((startY - rect.y()) / actualSampleSize == 0);
if (swapOnly) {
if (!this->allocPixelRef(bitmap, NULL)) {
return return_false(*cinfo, *bitmap, "allocPixelRef");
}
} else {
if (!bitmap->allocPixels()) {
return return_false(*cinfo, *bitmap, "allocPixels");
}
}
SkAutoLockPixels alp(*bitmap);
if (!sampler.begin(bitmap, sc, this->getDitherImage())) {
return return_false(*cinfo, *bitmap, "sampler.begin");
}
uint8_t* srcRow = (uint8_t*)srcStorage.reset(width * 4);
// Possibly skip initial rows [sampler.srcY0]
if (!skip_src_rows_tile(cinfo, index->index, srcRow, sampler.srcY0())) {
return return_false(*cinfo, *bitmap, "skip rows");
}
// now loop through scanlines until y == bitmap->height() - 1
for (int y = 0;; y++) {
JSAMPLE* rowptr = (JSAMPLE*)srcRow;
int row_count = jpeg_read_tile_scanline(cinfo, index->index, &rowptr);
if (0 == row_count) {
return return_false(*cinfo, *bitmap, "read_scanlines");
}
if (this->shouldCancelDecode()) {
return return_false(*cinfo, *bitmap, "shouldCancelDecode");
}
sampler.next(srcRow);
if (bitmap->height() - 1 == y) {
// we're done
break;
}
if (!skip_src_rows_tile(cinfo, index->index, srcRow,
sampler.srcDY() - 1)) {
return return_false(*cinfo, *bitmap, "skip rows");
}
}
if (swapOnly) {
bm->swap(*bitmap);
} else {
cropBitmap(bm, bitmap, actualSampleSize, region.x(), region.y(),
region.width(), region.height(), startX, startY);
}
return true;
}
