| /* |
| * Copyright (C) 2010 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of |
| * its contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "platform/image-decoders/webp/WEBPImageDecoder.h" |
| |
| #if CPU(BIG_ENDIAN) || CPU(MIDDLE_ENDIAN) |
| #error Blink assumes a little-endian target. |
| #endif |
| |
| #if SK_B32_SHIFT // Output little-endian RGBA pixels (Android). |
| inline WEBP_CSP_MODE outputMode(bool hasAlpha) { |
| return hasAlpha ? MODE_rgbA : MODE_RGBA; |
| } |
| #else // Output little-endian BGRA pixels. |
| inline WEBP_CSP_MODE outputMode(bool hasAlpha) { |
| return hasAlpha ? MODE_bgrA : MODE_BGRA; |
| } |
| #endif |
| |
| inline uint8_t blendChannel(uint8_t src, |
| uint8_t srcA, |
| uint8_t dst, |
| uint8_t dstA, |
| unsigned scale) { |
| unsigned blendUnscaled = src * srcA + dst * dstA; |
| ASSERT(blendUnscaled < (1ULL << 32) / scale); |
| return (blendUnscaled * scale) >> 24; |
| } |
| |
| inline uint32_t blendSrcOverDstNonPremultiplied(uint32_t src, uint32_t dst) { |
| uint8_t srcA = SkGetPackedA32(src); |
| if (srcA == 0) |
| return dst; |
| |
| uint8_t dstA = SkGetPackedA32(dst); |
| uint8_t dstFactorA = (dstA * SkAlpha255To256(255 - srcA)) >> 8; |
| ASSERT(srcA + dstFactorA < (1U << 8)); |
| uint8_t blendA = srcA + dstFactorA; |
| unsigned scale = (1UL << 24) / blendA; |
| |
| uint8_t blendR = blendChannel(SkGetPackedR32(src), srcA, SkGetPackedR32(dst), |
| dstFactorA, scale); |
| uint8_t blendG = blendChannel(SkGetPackedG32(src), srcA, SkGetPackedG32(dst), |
| dstFactorA, scale); |
| uint8_t blendB = blendChannel(SkGetPackedB32(src), srcA, SkGetPackedB32(dst), |
| dstFactorA, scale); |
| |
| return SkPackARGB32NoCheck(blendA, blendR, blendG, blendB); |
| } |
| |
| // Returns two point ranges (<left, width> pairs) at row |canvasY| which belong |
| // to |src| but not |dst|. A range is empty if its width is 0. |
| inline void findBlendRangeAtRow(const blink::IntRect& src, |
| const blink::IntRect& dst, |
| int canvasY, |
| int& left1, |
| int& width1, |
| int& left2, |
| int& width2) { |
| SECURITY_DCHECK(canvasY >= src.y() && canvasY < src.maxY()); |
| left1 = -1; |
| width1 = 0; |
| left2 = -1; |
| width2 = 0; |
| |
| if (canvasY < dst.y() || canvasY >= dst.maxY() || src.x() >= dst.maxX() || |
| src.maxX() <= dst.x()) { |
| left1 = src.x(); |
| width1 = src.width(); |
| return; |
| } |
| |
| if (src.x() < dst.x()) { |
| left1 = src.x(); |
| width1 = dst.x() - src.x(); |
| } |
| |
| if (src.maxX() > dst.maxX()) { |
| left2 = dst.maxX(); |
| width2 = src.maxX() - dst.maxX(); |
| } |
| } |
| |
| void alphaBlendPremultiplied(blink::ImageFrame& src, |
| blink::ImageFrame& dst, |
| int canvasY, |
| int left, |
| int width) { |
| for (int x = 0; x < width; ++x) { |
| int canvasX = left + x; |
| blink::ImageFrame::PixelData& pixel = *src.getAddr(canvasX, canvasY); |
| if (SkGetPackedA32(pixel) != 0xff) { |
| blink::ImageFrame::PixelData prevPixel = *dst.getAddr(canvasX, canvasY); |
| pixel = SkPMSrcOver(pixel, prevPixel); |
| } |
| } |
| } |
| |
| void alphaBlendNonPremultiplied(blink::ImageFrame& src, |
| blink::ImageFrame& dst, |
| int canvasY, |
| int left, |
| int width) { |
| for (int x = 0; x < width; ++x) { |
| int canvasX = left + x; |
| blink::ImageFrame::PixelData& pixel = *src.getAddr(canvasX, canvasY); |
| if (SkGetPackedA32(pixel) != 0xff) { |
| blink::ImageFrame::PixelData prevPixel = *dst.getAddr(canvasX, canvasY); |
| pixel = blendSrcOverDstNonPremultiplied(pixel, prevPixel); |
| } |
| } |
| } |
| |
| namespace blink { |
| |
| WEBPImageDecoder::WEBPImageDecoder(AlphaOption alphaOption, |
| ColorSpaceOption colorOptions, |
| size_t maxDecodedBytes) |
| : ImageDecoder(alphaOption, colorOptions, maxDecodedBytes), |
| m_decoder(0), |
| m_formatFlags(0), |
| m_frameBackgroundHasAlpha(false), |
| m_demux(0), |
| m_demuxState(WEBP_DEMUX_PARSING_HEADER), |
| m_haveAlreadyParsedThisData(false), |
| m_repetitionCount(cAnimationLoopOnce), |
| m_decodedHeight(0) { |
| m_blendFunction = (alphaOption == AlphaPremultiplied) |
| ? alphaBlendPremultiplied |
| : alphaBlendNonPremultiplied; |
| } |
| |
| WEBPImageDecoder::~WEBPImageDecoder() { |
| clear(); |
| } |
| |
| void WEBPImageDecoder::clear() { |
| WebPDemuxDelete(m_demux); |
| m_demux = 0; |
| m_consolidatedData.reset(); |
| clearDecoder(); |
| } |
| |
| void WEBPImageDecoder::clearDecoder() { |
| WebPIDelete(m_decoder); |
| m_decoder = 0; |
| m_decodedHeight = 0; |
| m_frameBackgroundHasAlpha = false; |
| } |
| |
| void WEBPImageDecoder::onSetData(SegmentReader*) { |
| m_haveAlreadyParsedThisData = false; |
| } |
| |
| int WEBPImageDecoder::repetitionCount() const { |
| return failed() ? cAnimationLoopOnce : m_repetitionCount; |
| } |
| |
| bool WEBPImageDecoder::frameIsCompleteAtIndex(size_t index) const { |
| if (!m_demux || m_demuxState <= WEBP_DEMUX_PARSING_HEADER) |
| return false; |
| if (!(m_formatFlags & ANIMATION_FLAG)) |
| return ImageDecoder::frameIsCompleteAtIndex(index); |
| bool frameIsLoadedAtIndex = index < m_frameBufferCache.size(); |
| return frameIsLoadedAtIndex; |
| } |
| |
| float WEBPImageDecoder::frameDurationAtIndex(size_t index) const { |
| return index < m_frameBufferCache.size() |
| ? m_frameBufferCache[index].duration() |
| : 0; |
| } |
| |
| bool WEBPImageDecoder::updateDemuxer() { |
| if (failed()) |
| return false; |
| |
| if (m_haveAlreadyParsedThisData) |
| return true; |
| |
| m_haveAlreadyParsedThisData = true; |
| |
| const unsigned webpHeaderSize = 30; |
| if (m_data->size() < webpHeaderSize) |
| return false; // Await VP8X header so WebPDemuxPartial succeeds. |
| |
| WebPDemuxDelete(m_demux); |
| m_consolidatedData = m_data->getAsSkData(); |
| WebPData inputData = { |
| reinterpret_cast<const uint8_t*>(m_consolidatedData->data()), |
| m_consolidatedData->size()}; |
| m_demux = WebPDemuxPartial(&inputData, &m_demuxState); |
| if (!m_demux || (isAllDataReceived() && m_demuxState != WEBP_DEMUX_DONE)) { |
| if (!m_demux) |
| m_consolidatedData.reset(); |
| return setFailed(); |
| } |
| |
| ASSERT(m_demuxState > WEBP_DEMUX_PARSING_HEADER); |
| if (!WebPDemuxGetI(m_demux, WEBP_FF_FRAME_COUNT)) |
| return false; // Wait until the encoded image frame data arrives. |
| |
| if (!isDecodedSizeAvailable()) { |
| int width = WebPDemuxGetI(m_demux, WEBP_FF_CANVAS_WIDTH); |
| int height = WebPDemuxGetI(m_demux, WEBP_FF_CANVAS_HEIGHT); |
| if (!setSize(width, height)) |
| return setFailed(); |
| |
| m_formatFlags = WebPDemuxGetI(m_demux, WEBP_FF_FORMAT_FLAGS); |
| if (!(m_formatFlags & ANIMATION_FLAG)) { |
| m_repetitionCount = cAnimationNone; |
| } else { |
| // Since we have parsed at least one frame, even if partially, |
| // the global animation (ANIM) properties have been read since |
| // an ANIM chunk must precede the ANMF frame chunks. |
| m_repetitionCount = WebPDemuxGetI(m_demux, WEBP_FF_LOOP_COUNT); |
| // Repetition count is always <= 16 bits. |
| ASSERT(m_repetitionCount == (m_repetitionCount & 0xffff)); |
| if (!m_repetitionCount) |
| m_repetitionCount = cAnimationLoopInfinite; |
| // FIXME: Implement ICC profile support for animated images. |
| m_formatFlags &= ~ICCP_FLAG; |
| } |
| |
| if ((m_formatFlags & ICCP_FLAG) && !ignoresColorSpace()) |
| readColorProfile(); |
| } |
| |
| ASSERT(isDecodedSizeAvailable()); |
| |
| size_t frameCount = WebPDemuxGetI(m_demux, WEBP_FF_FRAME_COUNT); |
| updateAggressivePurging(frameCount); |
| |
| return true; |
| } |
| |
| bool WEBPImageDecoder::initFrameBuffer(size_t frameIndex) { |
| ImageFrame& buffer = m_frameBufferCache[frameIndex]; |
| if (buffer.getStatus() != ImageFrame::FrameEmpty) // Already initialized. |
| return true; |
| |
| const size_t requiredPreviousFrameIndex = buffer.requiredPreviousFrameIndex(); |
| if (requiredPreviousFrameIndex == kNotFound) { |
| // This frame doesn't rely on any previous data. |
| if (!buffer.setSizeAndColorSpace(size().width(), size().height(), |
| colorSpace())) |
| return setFailed(); |
| m_frameBackgroundHasAlpha = |
| !buffer.originalFrameRect().contains(IntRect(IntPoint(), size())); |
| } else { |
| ImageFrame& prevBuffer = m_frameBufferCache[requiredPreviousFrameIndex]; |
| ASSERT(prevBuffer.getStatus() == ImageFrame::FrameComplete); |
| |
| // Preserve the last frame as the starting state for this frame. We try |
| // to reuse |prevBuffer| as starting state to avoid copying. |
| // For BlendAtopPreviousFrame, both frames are required, so we can't |
| // take over its image data using takeBitmapDataIfWritable. |
| if ((buffer.getAlphaBlendSource() == ImageFrame::BlendAtopPreviousFrame || |
| !buffer.takeBitmapDataIfWritable(&prevBuffer)) && |
| !buffer.copyBitmapData(prevBuffer)) |
| return setFailed(); |
| |
| if (prevBuffer.getDisposalMethod() == ImageFrame::DisposeOverwriteBgcolor) { |
| // We want to clear the previous frame to transparent, without |
| // affecting pixels in the image outside of the frame. |
| const IntRect& prevRect = prevBuffer.originalFrameRect(); |
| ASSERT(!prevRect.contains(IntRect(IntPoint(), size()))); |
| buffer.zeroFillFrameRect(prevRect); |
| } |
| |
| m_frameBackgroundHasAlpha = |
| prevBuffer.hasAlpha() || |
| (prevBuffer.getDisposalMethod() == ImageFrame::DisposeOverwriteBgcolor); |
| } |
| |
| buffer.setStatus(ImageFrame::FramePartial); |
| // The buffer is transparent outside the decoded area while the image is |
| // loading. The correct alpha value for the frame will be set when it is fully |
| // decoded. |
| buffer.setHasAlpha(true); |
| return true; |
| } |
| |
| size_t WEBPImageDecoder::clearCacheExceptFrame(size_t clearExceptFrame) { |
| // If |clearExceptFrame| has status FrameComplete, we preserve that frame. |
| // Otherwise, we preserve the most recent previous frame with status |
| // FrameComplete whose data will be required to decode |clearExceptFrame|, |
| // either in initFrameBuffer() or ApplyPostProcessing(). All other frames can |
| // be cleared. |
| while ((clearExceptFrame < m_frameBufferCache.size()) && |
| (m_frameBufferCache[clearExceptFrame].getStatus() != |
| ImageFrame::FrameComplete)) |
| clearExceptFrame = |
| m_frameBufferCache[clearExceptFrame].requiredPreviousFrameIndex(); |
| |
| return ImageDecoder::clearCacheExceptFrame(clearExceptFrame); |
| } |
| |
| void WEBPImageDecoder::clearFrameBuffer(size_t frameIndex) { |
| if (m_demux && m_demuxState >= WEBP_DEMUX_PARSED_HEADER && |
| m_frameBufferCache[frameIndex].getStatus() == ImageFrame::FramePartial) { |
| // Clear the decoder state so that this partial frame can be decoded again |
| // when requested. |
| clearDecoder(); |
| } |
| ImageDecoder::clearFrameBuffer(frameIndex); |
| } |
| |
| void WEBPImageDecoder::readColorProfile() { |
| WebPChunkIterator chunkIterator; |
| if (!WebPDemuxGetChunk(m_demux, "ICCP", 1, &chunkIterator)) { |
| WebPDemuxReleaseChunkIterator(&chunkIterator); |
| return; |
| } |
| |
| const char* profileData = |
| reinterpret_cast<const char*>(chunkIterator.chunk.bytes); |
| size_t profileSize = chunkIterator.chunk.size; |
| |
| setColorProfileAndComputeTransform(profileData, profileSize); |
| |
| WebPDemuxReleaseChunkIterator(&chunkIterator); |
| } |
| |
| void WEBPImageDecoder::applyPostProcessing(size_t frameIndex) { |
| ImageFrame& buffer = m_frameBufferCache[frameIndex]; |
| int width; |
| int decodedHeight; |
| if (!WebPIDecGetRGB(m_decoder, &decodedHeight, &width, 0, 0)) |
| return; // See also https://bugs.webkit.org/show_bug.cgi?id=74062 |
| if (decodedHeight <= 0) |
| return; |
| |
| const IntRect& frameRect = buffer.originalFrameRect(); |
| SECURITY_DCHECK(width == frameRect.width()); |
| SECURITY_DCHECK(decodedHeight <= frameRect.height()); |
| const int left = frameRect.x(); |
| const int top = frameRect.y(); |
| |
| // TODO (msarett): |
| // Here we apply the color space transformation to the dst space. |
| // It does not really make sense to transform to a gamma-encoded |
| // space and then immediately after, perform a linear premultiply |
| // and linear blending. Can we find a way to perform the |
| // premultiplication and blending in a linear space? |
| SkColorSpaceXform* xform = colorTransform(); |
| if (xform) { |
| const SkColorSpaceXform::ColorFormat srcFormat = |
| SkColorSpaceXform::kBGRA_8888_ColorFormat; |
| const SkColorSpaceXform::ColorFormat dstFormat = |
| SkColorSpaceXform::kRGBA_8888_ColorFormat; |
| for (int y = m_decodedHeight; y < decodedHeight; ++y) { |
| const int canvasY = top + y; |
| uint8_t* row = reinterpret_cast<uint8_t*>(buffer.getAddr(left, canvasY)); |
| xform->apply(dstFormat, row, srcFormat, row, width, |
| kUnpremul_SkAlphaType); |
| |
| uint8_t* pixel = row; |
| for (int x = 0; x < width; ++x, pixel += 4) { |
| const int canvasX = left + x; |
| buffer.setRGBA(canvasX, canvasY, pixel[0], pixel[1], pixel[2], |
| pixel[3]); |
| } |
| } |
| } |
| |
| // During the decoding of the current frame, we may have set some pixels to be |
| // transparent (i.e. alpha < 255). If the alpha blend source was |
| // 'BlendAtopPreviousFrame', the values of these pixels should be determined |
| // by blending them against the pixels of the corresponding previous frame. |
| // Compute the correct opaque values now. |
| // FIXME: This could be avoided if libwebp decoder had an API that used the |
| // previous required frame to do the alpha-blending by itself. |
| if ((m_formatFlags & ANIMATION_FLAG) && frameIndex && |
| buffer.getAlphaBlendSource() == ImageFrame::BlendAtopPreviousFrame && |
| buffer.requiredPreviousFrameIndex() != kNotFound) { |
| ImageFrame& prevBuffer = m_frameBufferCache[frameIndex - 1]; |
| ASSERT(prevBuffer.getStatus() == ImageFrame::FrameComplete); |
| ImageFrame::DisposalMethod prevDisposalMethod = |
| prevBuffer.getDisposalMethod(); |
| if (prevDisposalMethod == ImageFrame::DisposeKeep) { |
| // Blend transparent pixels with pixels in previous canvas. |
| for (int y = m_decodedHeight; y < decodedHeight; ++y) { |
| m_blendFunction(buffer, prevBuffer, top + y, left, width); |
| } |
| } else if (prevDisposalMethod == ImageFrame::DisposeOverwriteBgcolor) { |
| const IntRect& prevRect = prevBuffer.originalFrameRect(); |
| // We need to blend a transparent pixel with the starting value (from just |
| // after the initFrame() call). If the pixel belongs to prevRect, the |
| // starting value was fully transparent, so this is a no-op. Otherwise, we |
| // need to blend against the pixel from the previous canvas. |
| for (int y = m_decodedHeight; y < decodedHeight; ++y) { |
| int canvasY = top + y; |
| int left1, width1, left2, width2; |
| findBlendRangeAtRow(frameRect, prevRect, canvasY, left1, width1, left2, |
| width2); |
| if (width1 > 0) |
| m_blendFunction(buffer, prevBuffer, canvasY, left1, width1); |
| if (width2 > 0) |
| m_blendFunction(buffer, prevBuffer, canvasY, left2, width2); |
| } |
| } |
| } |
| |
| m_decodedHeight = decodedHeight; |
| buffer.setPixelsChanged(true); |
| } |
| |
| size_t WEBPImageDecoder::decodeFrameCount() { |
| // If updateDemuxer() fails, return the existing number of frames. This way |
| // if we get halfway through the image before decoding fails, we won't |
| // suddenly start reporting that the image has zero frames. |
| return updateDemuxer() ? WebPDemuxGetI(m_demux, WEBP_FF_FRAME_COUNT) |
| : m_frameBufferCache.size(); |
| } |
| |
| void WEBPImageDecoder::initializeNewFrame(size_t index) { |
| if (!(m_formatFlags & ANIMATION_FLAG)) { |
| ASSERT(!index); |
| return; |
| } |
| WebPIterator animatedFrame; |
| WebPDemuxGetFrame(m_demux, index + 1, &animatedFrame); |
| ASSERT(animatedFrame.complete == 1); |
| ImageFrame* buffer = &m_frameBufferCache[index]; |
| IntRect frameRect(animatedFrame.x_offset, animatedFrame.y_offset, |
| animatedFrame.width, animatedFrame.height); |
| buffer->setOriginalFrameRect( |
| intersection(frameRect, IntRect(IntPoint(), size()))); |
| buffer->setDuration(animatedFrame.duration); |
| buffer->setDisposalMethod(animatedFrame.dispose_method == |
| WEBP_MUX_DISPOSE_BACKGROUND |
| ? ImageFrame::DisposeOverwriteBgcolor |
| : ImageFrame::DisposeKeep); |
| buffer->setAlphaBlendSource(animatedFrame.blend_method == WEBP_MUX_BLEND |
| ? ImageFrame::BlendAtopPreviousFrame |
| : ImageFrame::BlendAtopBgcolor); |
| buffer->setRequiredPreviousFrameIndex( |
| findRequiredPreviousFrame(index, !animatedFrame.has_alpha)); |
| WebPDemuxReleaseIterator(&animatedFrame); |
| } |
| |
| void WEBPImageDecoder::decode(size_t index) { |
| if (failed()) |
| return; |
| |
| Vector<size_t> framesToDecode; |
| size_t frameToDecode = index; |
| do { |
| framesToDecode.append(frameToDecode); |
| frameToDecode = |
| m_frameBufferCache[frameToDecode].requiredPreviousFrameIndex(); |
| } while (frameToDecode != kNotFound && |
| m_frameBufferCache[frameToDecode].getStatus() != |
| ImageFrame::FrameComplete); |
| |
| ASSERT(m_demux); |
| for (auto i = framesToDecode.rbegin(); i != framesToDecode.rend(); ++i) { |
| if ((m_formatFlags & ANIMATION_FLAG) && !initFrameBuffer(*i)) |
| return; |
| WebPIterator webpFrame; |
| if (!WebPDemuxGetFrame(m_demux, *i + 1, &webpFrame)) { |
| setFailed(); |
| } else { |
| decodeSingleFrame(webpFrame.fragment.bytes, webpFrame.fragment.size, *i); |
| WebPDemuxReleaseIterator(&webpFrame); |
| } |
| if (failed()) |
| return; |
| |
| // We need more data to continue decoding. |
| if (m_frameBufferCache[*i].getStatus() != ImageFrame::FrameComplete) |
| break; |
| |
| if (m_purgeAggressively) |
| clearCacheExceptFrame(*i); |
| } |
| |
| // It is also a fatal error if all data is received and we have decoded all |
| // frames available but the file is truncated. |
| if (index >= m_frameBufferCache.size() - 1 && isAllDataReceived() && |
| m_demux && m_demuxState != WEBP_DEMUX_DONE) |
| setFailed(); |
| } |
| |
| bool WEBPImageDecoder::decodeSingleFrame(const uint8_t* dataBytes, |
| size_t dataSize, |
| size_t frameIndex) { |
| if (failed()) |
| return false; |
| |
| ASSERT(isDecodedSizeAvailable()); |
| |
| ASSERT(m_frameBufferCache.size() > frameIndex); |
| ImageFrame& buffer = m_frameBufferCache[frameIndex]; |
| ASSERT(buffer.getStatus() != ImageFrame::FrameComplete); |
| |
| if (buffer.getStatus() == ImageFrame::FrameEmpty) { |
| if (!buffer.setSizeAndColorSpace(size().width(), size().height(), |
| colorSpace())) |
| return setFailed(); |
| buffer.setStatus(ImageFrame::FramePartial); |
| // The buffer is transparent outside the decoded area while the image is |
| // loading. The correct alpha value for the frame will be set when it is |
| // fully decoded. |
| buffer.setHasAlpha(true); |
| buffer.setOriginalFrameRect(IntRect(IntPoint(), size())); |
| } |
| |
| const IntRect& frameRect = buffer.originalFrameRect(); |
| if (!m_decoder) { |
| WEBP_CSP_MODE mode = outputMode(m_formatFlags & ALPHA_FLAG); |
| if (!m_premultiplyAlpha) |
| mode = outputMode(false); |
| if (colorTransform()) { |
| // Swizzling between RGBA and BGRA is zero cost in a color transform. |
| // So when we have a color transform, we should decode to whatever is |
| // easiest for libwebp, and then let the color transform swizzle if |
| // necessary. |
| // Lossy webp is encoded as YUV (so RGBA and BGRA are the same cost). |
| // Lossless webp is encoded as BGRA. This means decoding to BGRA is |
| // either faster or the same cost as RGBA. |
| mode = MODE_BGRA; |
| } |
| WebPInitDecBuffer(&m_decoderBuffer); |
| m_decoderBuffer.colorspace = mode; |
| m_decoderBuffer.u.RGBA.stride = |
| size().width() * sizeof(ImageFrame::PixelData); |
| m_decoderBuffer.u.RGBA.size = |
| m_decoderBuffer.u.RGBA.stride * frameRect.height(); |
| m_decoderBuffer.is_external_memory = 1; |
| m_decoder = WebPINewDecoder(&m_decoderBuffer); |
| if (!m_decoder) |
| return setFailed(); |
| } |
| |
| m_decoderBuffer.u.RGBA.rgba = |
| reinterpret_cast<uint8_t*>(buffer.getAddr(frameRect.x(), frameRect.y())); |
| |
| switch (WebPIUpdate(m_decoder, dataBytes, dataSize)) { |
| case VP8_STATUS_OK: |
| applyPostProcessing(frameIndex); |
| buffer.setHasAlpha((m_formatFlags & ALPHA_FLAG) || |
| m_frameBackgroundHasAlpha); |
| buffer.setStatus(ImageFrame::FrameComplete); |
| clearDecoder(); |
| return true; |
| case VP8_STATUS_SUSPENDED: |
| if (!isAllDataReceived() && !frameIsCompleteAtIndex(frameIndex)) { |
| applyPostProcessing(frameIndex); |
| return false; |
| } |
| // FALLTHROUGH |
| default: |
| clear(); |
| return setFailed(); |
| } |
| } |
| |
| } // namespace blink |