bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
#ifdef TIME_DECODE
AutoTimeMillis atm("JPEG Decode");
#endif
SkAutoMalloc srcStorage;
JPEGAutoClean autoClean;
jpeg_decompress_struct cinfo;
skjpeg_error_mgr sk_err;
skjpeg_source_mgr sk_stream(stream, this, false);
cinfo.err = jpeg_std_error(&sk_err);
sk_err.error_exit = skjpeg_error_exit;
// All objects need to be instantiated before this setjmp call so that
// they will be cleaned up properly if an error occurs.
if (setjmp(sk_err.fJmpBuf)) {
return return_false(cinfo, *bm, "setjmp");
}
jpeg_create_decompress(&cinfo);
autoClean.set(&cinfo);
#ifdef SK_BUILD_FOR_ANDROID
overwrite_mem_buffer_size(&cinfo);
#endif
//jpeg_stdio_src(&cinfo, file);
cinfo.src = &sk_stream;
int status = jpeg_read_header(&cinfo, true);
if (status != JPEG_HEADER_OK) {
return return_false(cinfo, *bm, "read_header");
}
/* Try to fulfill the requested sampleSize. Since jpeg can do it (when it
can) much faster that we, just use their num/denom api to approximate
the size.
*/
int sampleSize = this->getSampleSize();
if (this->getPreferQualityOverSpeed()) {
cinfo.dct_method = JDCT_ISLOW;
} else {
cinfo.dct_method = JDCT_IFAST;
}
cinfo.scale_num = 1;
cinfo.scale_denom = sampleSize;
/* this gives about 30% performance improvement. In theory it may
reduce the visual quality, in practice I'm not seeing a difference
*/
cinfo.do_fancy_upsampling = 0;
/* this gives another few percents */
cinfo.do_block_smoothing = 0;
/* default format is RGB */
cinfo.out_color_space = JCS_RGB;
SkBitmap::Config config = this->getPrefConfig(k32Bit_SrcDepth, false);
// only these make sense for jpegs
if (config != SkBitmap::kARGB_8888_Config &&
config != SkBitmap::kARGB_4444_Config &&
config != SkBitmap::kRGB_565_Config) {
config = SkBitmap::kARGB_8888_Config;
}
#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
if (sampleSize == 1 && mode == SkImageDecoder::kDecodeBounds_Mode) {
bm->setConfig(config, cinfo.image_width, cinfo.image_height);
bm->setIsOpaque(true);
return true;
}
/* image_width and image_height are the original dimensions, available
after jpeg_read_header(). To see the scaled dimensions, we have to call
jpeg_start_decompress(), and then read output_width and output_height.
*/
if (!jpeg_start_decompress(&cinfo)) {
/* If we failed here, we may still have enough information to return
to the caller if they just wanted (subsampled bounds). If sampleSize
was 1, then we would have already returned. Thus we just check if
we're in kDecodeBounds_Mode, and that we have valid output sizes.
One reason to fail here is that we have insufficient stream data
to complete the setup. However, output dimensions seem to get
computed very early, which is why this special check can pay off.
*/
if (SkImageDecoder::kDecodeBounds_Mode == mode &&
valid_output_dimensions(cinfo)) {
SkScaledBitmapSampler smpl(cinfo.output_width, cinfo.output_height,
recompute_sampleSize(sampleSize, cinfo));
bm->setConfig(config, smpl.scaledWidth(), smpl.scaledHeight());
bm->setIsOpaque(true);
return true;
} else {
return return_false(cinfo, *bm, "start_decompress");
}
}
sampleSize = recompute_sampleSize(sampleSize, cinfo);
// should we allow the Chooser (if present) to pick a config for us???
if (!this->chooseFromOneChoice(config, cinfo.output_width,
cinfo.output_height)) {
return return_false(cinfo, *bm, "chooseFromOneChoice");
}
#ifdef ANDROID_RGB
/* short-circuit the SkScaledBitmapSampler when possible, as this gives
a significant performance boost.
*/
if (sampleSize == 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)))
{
bm->lockPixels();
JSAMPLE* rowptr = (JSAMPLE*)bm->getPixels();
bm->unlockPixels();
bool reuseBitmap = (rowptr != NULL);
if (reuseBitmap && ((int) cinfo.output_width != bm->width() ||
(int) cinfo.output_height != bm->height())) {
// Dimensions must match
return false;
}
if (!reuseBitmap) {
bm->setConfig(config, cinfo.output_width, cinfo.output_height);
bm->setIsOpaque(true);
if (SkImageDecoder::kDecodeBounds_Mode == mode) {
return true;
}
if (!this->allocPixelRef(bm, NULL)) {
return return_false(cinfo, *bm, "allocPixelRef");
}
} else if (SkImageDecoder::kDecodeBounds_Mode == mode) {
return true;
}
SkAutoLockPixels alp(*bm);
rowptr = (JSAMPLE*)bm->getPixels();
INT32 const bpr = bm->rowBytes();
while (cinfo.output_scanline < cinfo.output_height) {
int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1);
// 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, *bm, "read_scanlines");
}
if (this->shouldCancelDecode()) {
return return_false(cinfo, *bm, "shouldCancelDecode");
}
rowptr += bpr;
}
if (reuseBitmap) {
bm->notifyPixelsChanged();
}
jpeg_finish_decompress(&cinfo);
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(cinfo.output_width, cinfo.output_height,
sampleSize);
bm->lockPixels();
JSAMPLE* rowptr = (JSAMPLE*)bm->getPixels();
bool reuseBitmap = (rowptr != NULL);
bm->unlockPixels();
if (reuseBitmap && (sampler.scaledWidth() != bm->width() ||
sampler.scaledHeight() != bm->height())) {
// Dimensions must match
return false;
}
if (!reuseBitmap) {
bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight());
// jpegs are always opaque (i.e. have no per-pixel alpha)
bm->setIsOpaque(true);
if (SkImageDecoder::kDecodeBounds_Mode == mode) {
return true;
}
if (!this->allocPixelRef(bm, NULL)) {
return return_false(cinfo, *bm, "allocPixelRef");
}
} else if (SkImageDecoder::kDecodeBounds_Mode == mode) {
return true;
}
SkAutoLockPixels alp(*bm);
if (!sampler.begin(bm, sc, this->getDitherImage())) {
return return_false(cinfo, *bm, "sampler.begin");
}
uint8_t* srcRow = (uint8_t*)srcStorage.reset(cinfo.output_width * 4);
// Possibly skip initial rows [sampler.srcY0]
if (!skip_src_rows(&cinfo, srcRow, sampler.srcY0())) {
return return_false(cinfo, *bm, "skip rows");
}
// now loop through scanlines until y == bm->height() - 1
for (int y = 0;; y++) {
JSAMPLE* rowptr = (JSAMPLE*)srcRow;
int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1);
if (0 == row_count) {
return return_false(cinfo, *bm, "read_scanlines");
}
if (this->shouldCancelDecode()) {
return return_false(cinfo, *bm, "shouldCancelDecode");
}
sampler.next(srcRow);
if (bm->height() - 1 == y) {
// we're done
break;
}
if (!skip_src_rows(&cinfo, srcRow, sampler.srcDY() - 1)) {
return return_false(cinfo, *bm, "skip rows");
}
}
// we formally skip the rest, so we don't get a complaint from libjpeg
if (!skip_src_rows(&cinfo, srcRow,
cinfo.output_height - cinfo.output_scanline)) {
return return_false(cinfo, *bm, "skip rows");
}
if (reuseBitmap) {
bm->notifyPixelsChanged();
}
jpeg_finish_decompress(&cinfo);
// SkDebugf("------------------- bm2 size %d [%d %d] %d\n", bm->getSize(), bm->width(), bm->height(), bm->config());
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;
}