SkWuffsCodec: fix dependent frames
SkWuffsCodec tells wuffs to decode only the current frame's
contribution, and then SkWuffsCodec blends it onto the prior frame (if
any). If there is a prior frame, do not call SkSampler::Fill, and blend
the new frame onto the old, rather than replacing it.
In addition, set rowsDecoded to scaledHeight to work properly for
scaled decodes.
TBR=reed@google.com No change to public API
Bug: skia:8235
Change-Id: I08e89f1083da3f9b98f93d8d2375ce78f0c378f8
Reviewed-on: https://skia-review.googlesource.com/c/171645
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Nigel Tao <nigeltao@google.com>
diff --git a/src/codec/SkWuffsCodec.cpp b/src/codec/SkWuffsCodec.cpp
index 4d2bbe7..090c234 100644
--- a/src/codec/SkWuffsCodec.cpp
+++ b/src/codec/SkWuffsCodec.cpp
@@ -173,6 +173,7 @@
bool onGetFrameInfo(int, FrameInfo*) const override;
int onGetRepetitionCount() override;
SkSampler* getSampler(bool createIfNecessary) override;
+ bool conversionSupported(const SkImageInfo& dst, bool, bool) override;
void readFrames();
Result seekFrame(int frameIndex);
@@ -389,6 +390,26 @@
return SkCodec::kSuccess;
}
+static bool independent_frame(SkCodec* codec, int frameIndex) {
+ if (frameIndex == 0) {
+ return true;
+ }
+
+ SkCodec::FrameInfo frameInfo;
+ SkAssertResult(codec->getFrameInfo(frameIndex, &frameInfo));
+ return frameInfo.fRequiredFrame == SkCodec::kNoFrame;
+}
+
+static void blend(uint32_t* dst, const uint32_t* src, int width) {
+ while (width --> 0) {
+ if (*src != 0) {
+ *dst = *src;
+ }
+ src++;
+ dst++;
+ }
+}
+
SkCodec::Result SkWuffsCodec::onIncrementalDecode(int* rowsDecoded) {
if (!fIncrDecDst) {
return SkCodec::kInternalError;
@@ -418,6 +439,7 @@
return SkCodec::kErrorInInput;
}
+ const bool independent = independent_frame(this, options().fFrameIndex);
wuffs_base__rect_ie_u32 r = fFrameConfig.bounds();
if (!fSwizzler) {
SkIRect swizzleRect = SkIRect::MakeLTRB(r.min_incl_x, 0, r.max_excl_x, 1);
@@ -426,9 +448,12 @@
fSwizzler->setSampleX(fSpySampler.sampleX());
fSwizzler->setSampleY(fSpySampler.sampleY());
- auto fillInfo = dstInfo().makeWH(
- fSwizzler->fillWidth(), get_scaled_dimension(dstInfo().height(), fSwizzler->sampleY()));
- SkSampler::Fill(fillInfo, fIncrDecDst, fIncrDecRowBytes, options().fZeroInitialized);
+ if (independent) {
+ auto fillInfo = dstInfo().makeWH(fSwizzler->fillWidth(),
+ get_scaled_dimension(this->dstInfo().height(),
+ fSwizzler->sampleY()));
+ SkSampler::Fill(fillInfo, fIncrDecDst, fIncrDecRowBytes, options().fZeroInitialized);
+ }
}
wuffs_base__slice_u8 palette = fPixelBuffer.palette();
@@ -439,6 +464,10 @@
fColorTable[i] = proc(p[3], p[2], p[1], p[0]);
}
+ std::unique_ptr<uint8_t[]> tmpBuffer;
+ if (!independent) {
+ tmpBuffer.reset(new uint8_t[dstInfo().minRowBytes()]);
+ }
wuffs_base__table_u8 pixels = fPixelBuffer.plane(0);
const int sampleY = fSwizzler->sampleY();
const int scaledHeight = get_scaled_dimension(dstInfo().height(), sampleY);
@@ -468,7 +497,16 @@
// To get from the start (in the X-direction) of the image to the start
// of the frame, we adjust s by (r.min_incl_x * src_bpp).
uint8_t* s = pixels.ptr + (y * pixels.stride) + (r.min_incl_x * src_bpp);
- fSwizzler->swizzle(d, s);
+ if (independent) {
+ fSwizzler->swizzle(d, s);
+ } else {
+ SkASSERT(tmpBuffer.get());
+ fSwizzler->swizzle(tmpBuffer.get(), s);
+ d = SkTAddOffset<uint8_t>(d, fSwizzler->swizzleOffsetBytes());
+ const auto* swizzled = SkTAddOffset<uint32_t>(tmpBuffer.get(),
+ fSwizzler->swizzleOffsetBytes());
+ blend(reinterpret_cast<uint32_t*>(d), swizzled, fSwizzler->swizzleWidth());
+ }
}
// The semantics of *rowsDecoded is: say you have a 10 pixel high image
@@ -484,8 +522,12 @@
// interlaced), we just zero-initialize all 10 rows ahead of time and
// return the height of the image, so the caller knows it doesn't need to
// do anything.
+ //
+ // Similarly, if the output is scaled, we zero-initialized all
+ // |scaledHeight| rows (the scaled image height), so we inform the caller
+ // that it doesn't need to do anything.
if (rowsDecoded) {
- *rowsDecoded = static_cast<int>(fPixelBuffer.pixcfg.height());
+ *rowsDecoded = scaledHeight;
}
if (result == SkCodec::kSuccess) {
@@ -543,6 +585,22 @@
return nullptr;
}
+bool SkWuffsCodec::conversionSupported(const SkImageInfo& dst, bool srcIsOpaque, bool needsColorXform) {
+ if (!this->INHERITED::conversionSupported(dst, srcIsOpaque, needsColorXform)) {
+ return false;
+ }
+
+ switch (dst.colorType()) {
+ case kRGBA_8888_SkColorType:
+ case kBGRA_8888_SkColorType:
+ return true;
+ default:
+ // FIXME: Add skcms to support F16
+ // FIXME: Add support for 565 on the first frame
+ return false;
+ }
+}
+
void SkWuffsCodec::readFrames() {
size_t n = fFrames.size();
int i = n ? n - 1 : 0;