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Diffstat (limited to 'src/codec/SkWebpCodec.cpp')
-rw-r--r--src/codec/SkWebpCodec.cpp201
1 files changed, 86 insertions, 115 deletions
diff --git a/src/codec/SkWebpCodec.cpp b/src/codec/SkWebpCodec.cpp
index 2bc3507df4..dbc141ebd6 100644
--- a/src/codec/SkWebpCodec.cpp
+++ b/src/codec/SkWebpCodec.cpp
@@ -7,10 +7,9 @@
#include "SkCodecPriv.h"
#include "SkColorSpaceXform.h"
-#include "SkSampler.h"
+#include "SkWebpCodec.h"
#include "SkStreamPriv.h"
#include "SkTemplates.h"
-#include "SkWebpCodec.h"
// A WebP decoder on top of (subset of) libwebp
// For more information on WebP image format, and libwebp library, see:
@@ -60,21 +59,6 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
return nullptr;
}
- const int width = WebPDemuxGetI(demux, WEBP_FF_CANVAS_WIDTH);
- const int height = WebPDemuxGetI(demux, WEBP_FF_CANVAS_HEIGHT);
-
- // Sanity check for image size that's about to be decoded.
- {
- const int64_t size = sk_64_mul(width, height);
- if (!sk_64_isS32(size)) {
- return nullptr;
- }
- // now check that if we are 4-bytes per pixel, we also don't overflow
- if (sk_64_asS32(size) > (0x7FFFFFFF >> 2)) {
- return nullptr;
- }
- }
-
WebPChunkIterator chunkIterator;
SkAutoTCallVProc<WebPChunkIterator, WebPDemuxReleaseChunkIterator> autoCI(&chunkIterator);
sk_sp<SkColorSpace> colorSpace = nullptr;
@@ -89,15 +73,36 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
colorSpace = SkColorSpace::MakeNamed(SkColorSpace::kSRGB_Named);
}
- // Get the first frame and its "features" to determine the color and alpha types.
- // Since we do not yet support animated webp, this is the only frame that we will
- // decode.
+ // Since we do not yet support animation, we get the |width|, |height|, |color|, and |alpha|
+ // from the first frame. It's the only frame we will decode.
+ //
+ // TODO:
+ // When we support animation, we'll want to report the canvas width and canvas height instead.
+ // We can get these from the |demux| directly.
+ // What |color| and |alpha| will we want to report though? WebP allows different frames
+ // to be encoded in different ways, making the encoded format difficult to describe.
WebPIterator frame;
SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
if (!WebPDemuxGetFrame(demux, 1, &frame)) {
return nullptr;
}
+ // Sanity check for image size that's about to be decoded.
+ {
+ const int64_t size = sk_64_mul(frame.width, frame.height);
+ if (!sk_64_isS32(size)) {
+ return nullptr;
+ }
+ // now check that if we are 4-bytes per pixel, we also don't overflow
+ if (sk_64_asS32(size) > (0x7FFFFFFF >> 2)) {
+ return nullptr;
+ }
+ }
+
+ // TODO:
+ // The only reason we actually need to call WebPGetFeatures() is to get the |features.format|.
+ // This call actually re-reads the frame header. Should we suggest that libwebp expose
+ // the format on the |frame|?
WebPBitstreamFeatures features;
VP8StatusCode status = WebPGetFeatures(frame.fragment.bytes, frame.fragment.size, &features);
if (VP8_STATUS_OK != status) {
@@ -108,8 +113,8 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
SkEncodedInfo::Alpha alpha;
switch (features.format) {
case 0:
- // This indicates a "mixed" format. We could see this for
- // animated webps (multiple fragments).
+ // This indicates a "mixed" format. We would see this for
+ // animated webps or for webps encoded in multiple fragments.
// I believe that this is a rare case.
// We could also guess kYUV here, but I think it makes more
// sense to guess kBGRA which is likely closer to the final
@@ -120,7 +125,7 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
break;
case 1:
// This is the lossy format (YUV).
- if (SkToBool(features.has_alpha) || frame.width != width || frame.height != height) {
+ if (SkToBool(features.has_alpha)) {
color = SkEncodedInfo::kYUVA_Color;
alpha = SkEncodedInfo::kUnpremul_Alpha;
} else {
@@ -138,9 +143,9 @@ SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
}
SkEncodedInfo info = SkEncodedInfo::Make(color, alpha, 8);
- SkWebpCodec* codecOut = new SkWebpCodec(width, height, info, std::move(colorSpace),
- streamDeleter.release(), demux.release(),
- std::move(data));
+ SkWebpCodec* codecOut = new SkWebpCodec(features.width, features.height, info,
+ std::move(colorSpace), streamDeleter.release(),
+ demux.release(), std::move(data));
codecOut->setUnsupportedICC(unsupportedICC);
return codecOut;
}
@@ -212,85 +217,48 @@ SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
// Free any memory associated with the buffer. Must be called last, so we declare it first.
SkAutoTCallVProc<WebPDecBuffer, WebPFreeDecBuffer> autoFree(&(config.output));
- WebPIterator frame;
- SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
- // If this succeeded in NewFromStream(), it should succeed again here.
- SkAssertResult(WebPDemuxGetFrame(fDemux, 1, &frame));
-
- // Get the frameRect. libwebp will have already signaled an error if this is not fully
- // contained by the canvas.
- auto frameRect = SkIRect::MakeXYWH(frame.x_offset, frame.y_offset, frame.width, frame.height);
- SkASSERT(this->getInfo().bounds().contains(frameRect));
- bool frameIsSubset = frameRect.size() != this->getInfo().dimensions();
- if (frameIsSubset) {
- SkSampler::Fill(dstInfo, dst, rowBytes, 0, options.fZeroInitialized);
- }
-
- int dstX = frameRect.x();
- int dstY = frameRect.y();
- int subsetWidth = frameRect.width();
- int subsetHeight = frameRect.height();
+ SkIRect bounds = SkIRect::MakeSize(this->getInfo().dimensions());
if (options.fSubset) {
- SkIRect subset = *options.fSubset;
- SkASSERT(this->getInfo().bounds().contains(subset));
- SkASSERT(SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
- SkASSERT(this->getValidSubset(&subset) && subset == *options.fSubset);
-
- if (!SkIRect::IntersectsNoEmptyCheck(subset, frameRect)) {
- return kSuccess;
+ // Caller is requesting a subset.
+ if (!bounds.contains(*options.fSubset)) {
+ // The subset is out of bounds.
+ return kInvalidParameters;
}
- int minXOffset = SkTMin(dstX, subset.x());
- int minYOffset = SkTMin(dstY, subset.y());
- dstX -= minXOffset;
- dstY -= minYOffset;
- frameRect.offset(-minXOffset, -minYOffset);
- subset.offset(-minXOffset, -minYOffset);
+ bounds = *options.fSubset;
- // Just like we require that the requested subset x and y offset are even, libwebp
- // guarantees that the frame x and y offset are even (it's actually impossible to specify
- // an odd frame offset). So we can still guarantee that the adjusted offsets are even.
- SkASSERT(SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
+ // This is tricky. libwebp snaps the top and left to even values. We could let libwebp
+ // do the snap, and return a subset which is a different one than requested. The problem
+ // with that approach is that the caller may try to stitch subsets together, and if we
+ // returned different subsets than requested, there would be artifacts at the boundaries.
+ // Instead, we report that we cannot support odd values for top and left..
+ if (!SkIsAlign2(bounds.fLeft) || !SkIsAlign2(bounds.fTop)) {
+ return kInvalidParameters;
+ }
- SkIRect intersection;
- SkAssertResult(intersection.intersect(frameRect, subset));
- subsetWidth = intersection.width();
- subsetHeight = intersection.height();
+#ifdef SK_DEBUG
+ {
+ // Make a copy, since getValidSubset can change its input.
+ SkIRect subset(bounds);
+ // That said, getValidSubset should *not* change its input, in this case; otherwise
+ // getValidSubset does not match the actual subsets we can do.
+ SkASSERT(this->getValidSubset(&subset) && subset == bounds);
+ }
+#endif
config.options.use_cropping = 1;
- config.options.crop_left = subset.x();
- config.options.crop_top = subset.y();
- config.options.crop_width = subsetWidth;
- config.options.crop_height = subsetHeight;
+ config.options.crop_left = bounds.fLeft;
+ config.options.crop_top = bounds.fTop;
+ config.options.crop_width = bounds.width();
+ config.options.crop_height = bounds.height();
}
- // Ignore the frame size and offset when determining if scaling is necessary.
- int scaledWidth = subsetWidth;
- int scaledHeight = subsetHeight;
- SkISize srcSize = options.fSubset ? options.fSubset->size() : this->getInfo().dimensions();
- if (srcSize != dstInfo.dimensions()) {
+ SkISize dstDimensions = dstInfo.dimensions();
+ if (bounds.size() != dstDimensions) {
+ // Caller is requesting scaling.
config.options.use_scaling = 1;
-
- if (frameIsSubset) {
- float scaleX = ((float) dstInfo.width()) / srcSize.width();
- float scaleY = ((float) dstInfo.height()) / srcSize.height();
-
- // We need to be conservative here and floor rather than round.
- // Otherwise, we may find ourselves decoding off the end of memory.
- dstX = scaleX * dstX;
- scaledWidth = scaleX * scaledWidth;
- dstY = scaleY * dstY;
- scaledHeight = scaleY * scaledHeight;
- if (0 == scaledWidth || 0 == scaledHeight) {
- return kSuccess;
- }
- } else {
- scaledWidth = dstInfo.width();
- scaledHeight = dstInfo.height();
- }
-
- config.options.scaled_width = scaledWidth;
- config.options.scaled_height = scaledHeight;
+ config.options.scaled_width = dstDimensions.width();
+ config.options.scaled_height = dstDimensions.height();
}
// Swizzling between RGBA and BGRA is zero cost in a color transform. So when we have a
@@ -306,17 +274,21 @@ SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
// does not provide a row-by-row API. This is a shame particularly in the F16 case,
// where we need to allocate an extra image-sized buffer.
SkAutoTMalloc<uint32_t> pixels;
- bool isF16 = kRGBA_F16_SkColorType == dstInfo.colorType();
- void* webpDst = isF16 ? pixels.reset(dstInfo.width() * dstInfo.height()) : dst;
- size_t webpRowBytes = isF16 ? dstInfo.width() * sizeof(uint32_t) : rowBytes;
- size_t totalBytes = isF16 ? webpRowBytes * dstInfo.height() : dstInfo.getSafeSize(webpRowBytes);
- size_t dstBpp = SkColorTypeBytesPerPixel(dstInfo.colorType());
- size_t webpBpp = isF16 ? sizeof(uint32_t) : dstBpp;
-
- size_t offset = dstX * webpBpp + dstY * webpRowBytes;
- config.output.u.RGBA.rgba = SkTAddOffset<uint8_t>(webpDst, offset);
- config.output.u.RGBA.stride = (int) webpRowBytes;
- config.output.u.RGBA.size = totalBytes - offset;
+ if (kRGBA_F16_SkColorType == dstInfo.colorType()) {
+ pixels.reset(dstDimensions.width() * dstDimensions.height());
+ config.output.u.RGBA.rgba = (uint8_t*) pixels.get();
+ config.output.u.RGBA.stride = (int) dstDimensions.width() * sizeof(uint32_t);
+ config.output.u.RGBA.size = config.output.u.RGBA.stride * dstDimensions.height();
+ } else {
+ config.output.u.RGBA.rgba = (uint8_t*) dst;
+ config.output.u.RGBA.stride = (int) rowBytes;
+ config.output.u.RGBA.size = dstInfo.getSafeSize(rowBytes);
+ }
+
+ WebPIterator frame;
+ SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
+ // If this succeeded in NewFromStream(), it should succeed again here.
+ SkAssertResult(WebPDemuxGetFrame(fDemux, 1, &frame));
SkAutoTCallVProc<WebPIDecoder, WebPIDelete> idec(WebPIDecode(nullptr, 0, &config));
if (!idec) {
@@ -327,12 +299,12 @@ SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
SkCodec::Result result;
switch (WebPIUpdate(idec, frame.fragment.bytes, frame.fragment.size)) {
case VP8_STATUS_OK:
- rowsDecoded = scaledHeight;
+ rowsDecoded = dstInfo.height();
result = kSuccess;
break;
case VP8_STATUS_SUSPENDED:
- WebPIDecGetRGB(idec, &rowsDecoded, nullptr, nullptr, nullptr);
- *rowsDecodedPtr = rowsDecoded + dstY;
+ WebPIDecGetRGB(idec, rowsDecodedPtr, nullptr, nullptr, nullptr);
+ rowsDecoded = *rowsDecodedPtr;
result = kIncompleteInput;
break;
default:
@@ -344,15 +316,14 @@ SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
SkAlphaType xformAlphaType = select_xform_alpha(dstInfo.alphaType(),
this->getInfo().alphaType());
- uint32_t* xformSrc = (uint32_t*) config.output.u.RGBA.rgba;
- void* xformDst = SkTAddOffset<void>(dst, dstBpp * dstX + rowBytes * dstY);
+ uint32_t* src = (uint32_t*) config.output.u.RGBA.rgba;
size_t srcRowBytes = config.output.u.RGBA.stride;
for (int y = 0; y < rowsDecoded; y++) {
- SkAssertResult(this->colorXform()->apply(dstColorFormat, xformDst,
- SkColorSpaceXform::kBGRA_8888_ColorFormat, xformSrc, scaledWidth,
+ SkAssertResult(this->colorXform()->apply(dstColorFormat, dst,
+ SkColorSpaceXform::kBGRA_8888_ColorFormat, src, dstInfo.width(),
xformAlphaType));
- xformDst = SkTAddOffset<void>(xformDst, rowBytes);
- xformSrc = SkTAddOffset<uint32_t>(xformSrc, srcRowBytes);
+ dst = SkTAddOffset<void>(dst, rowBytes);
+ src = SkTAddOffset<uint32_t>(src, srcRowBytes);
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-23 16:41:06 +0000