Animated WebP: Optimize decoding in case of seeking

Source/core/platform/image-decoders/webp/WEBPImageDecoderTest.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 164 matching lines @@
     EXPECT_EQ(cAnimationLoopOnce, decoder->repetitionCount());
 
     RefPtr<SharedBuffer> data = readFile("/LayoutTests/fast/images/resources/webp-animated.webp");
     ASSERT_TRUE(data.get());
     decoder->setData(data.get(), true);
 
     const int canvasWidth = 11;
     const int canvasHeight = 29;
     const struct AnimParam {
         int xOffset, yOffset, width, height;
-        ImageFrame::FrameDisposalMethod dispose;
+        ImageFrame::DisposalMethod disposalMethod;
+        ImageFrame::AlphaBlendSource alphaBlendSource;
         unsigned duration;
         bool hasAlpha;
     } frameParameters[] = {
-        { 0, 0, 11, 29, ImageFrame::DisposeKeep, 1000u, true },
-        { 2, 10, 7, 17, ImageFrame::DisposeKeep, 500u, true },
-        { 2, 2, 7, 16, ImageFrame::DisposeKeep, 1000u, true },
+        { 0, 0, 11, 29, ImageFrame::DisposeKeep, ImageFrame::BlendAtopPreviousFrame, 1000u, true },
+        { 2, 10, 7, 17, ImageFrame::DisposeKeep, ImageFrame::BlendAtopPreviousFrame, 500u, true },
+        { 2, 2, 7, 16, ImageFrame::DisposeKeep, ImageFrame::BlendAtopPreviousFrame, 1000u, true },
     };
 
     for (size_t i = 0; i < ARRAY_SIZE(frameParameters); ++i) {
         const ImageFrame* const frame = decoder->frameBufferAtIndex(i);
         EXPECT_EQ(ImageFrame::FrameComplete, frame->status());
         EXPECT_EQ(canvasWidth, frame->getSkBitmap().width());
         EXPECT_EQ(canvasHeight, frame->getSkBitmap().height());
         EXPECT_EQ(frameParameters[i].xOffset, frame->originalFrameRect().x());
         EXPECT_EQ(frameParameters[i].yOffset, frame->originalFrameRect().y());
         EXPECT_EQ(frameParameters[i].width, frame->originalFrameRect().width());
         EXPECT_EQ(frameParameters[i].height, frame->originalFrameRect().height());
-        EXPECT_EQ(frameParameters[i].dispose, frame->disposalMethod());
+        EXPECT_EQ(frameParameters[i].disposalMethod, frame->disposalMethod());
+        EXPECT_EQ(frameParameters[i].alphaBlendSource, frame->alphaBlendSource());
         EXPECT_EQ(frameParameters[i].duration, frame->duration());
         EXPECT_EQ(frameParameters[i].hasAlpha, frame->hasAlpha());
     }
 
     EXPECT_EQ(ARRAY_SIZE(frameParameters), decoder->frameCount());
     EXPECT_EQ(cAnimationLoopInfinite, decoder->repetitionCount());
 }
 
 TEST_F(AnimatedWebPTests, verifyAnimationParametersOpaqueFramesTransparentBackground)
 {
     OwnPtr<WEBPImageDecoder> decoder = createDecoder();
     EXPECT_EQ(cAnimationLoopOnce, decoder->repetitionCount());
 
     RefPtr<SharedBuffer> data = readFile("/LayoutTests/fast/images/resources/webp-animated-opaque.webp");
     ASSERT_TRUE(data.get());
     decoder->setData(data.get(), true);
 
     const int canvasWidth = 94;
     const int canvasHeight = 87;
     const struct AnimParam {
         int xOffset, yOffset, width, height;
-        ImageFrame::FrameDisposalMethod dispose;
+        ImageFrame::DisposalMethod disposalMethod;
+        ImageFrame::AlphaBlendSource alphaBlendSource;
         unsigned duration;
         bool hasAlpha;
     } frameParameters[] = {
-        { 4, 10, 33, 32, ImageFrame::DisposeOverwriteBgcolor, 1000u, true },
-        { 34, 30, 33, 32, ImageFrame::DisposeOverwriteBgcolor, 1000u, true },
-        { 62, 50, 32, 32, ImageFrame::DisposeOverwriteBgcolor, 1000u, true },
-        { 10, 54, 32, 33, ImageFrame::DisposeOverwriteBgcolor, 1000u, true },
+        { 4, 10, 33, 32, ImageFrame::DisposeOverwriteBgcolor, ImageFrame::BlendAtopPreviousFrame, 1000u, true },
+        { 34, 30, 33, 32, ImageFrame::DisposeOverwriteBgcolor, ImageFrame::BlendAtopPreviousFrame, 1000u, true },
+        { 62, 50, 32, 32, ImageFrame::DisposeOverwriteBgcolor, ImageFrame::BlendAtopPreviousFrame, 1000u, true },
+        { 10, 54, 32, 33, ImageFrame::DisposeOverwriteBgcolor, ImageFrame::BlendAtopPreviousFrame, 1000u, true },
     };
 
     for (size_t i = 0; i < ARRAY_SIZE(frameParameters); ++i) {
         const ImageFrame* const frame = decoder->frameBufferAtIndex(i);
         EXPECT_EQ(ImageFrame::FrameComplete, frame->status());
         EXPECT_EQ(canvasWidth, frame->getSkBitmap().width());
         EXPECT_EQ(canvasHeight, frame->getSkBitmap().height());
         EXPECT_EQ(frameParameters[i].xOffset, frame->originalFrameRect().x());
         EXPECT_EQ(frameParameters[i].yOffset, frame->originalFrameRect().y());
         EXPECT_EQ(frameParameters[i].width, frame->originalFrameRect().width());
         EXPECT_EQ(frameParameters[i].height, frame->originalFrameRect().height());
-        EXPECT_EQ(frameParameters[i].dispose, frame->disposalMethod());
+        EXPECT_EQ(frameParameters[i].disposalMethod, frame->disposalMethod());
+        EXPECT_EQ(frameParameters[i].alphaBlendSource, frame->alphaBlendSource());
         EXPECT_EQ(frameParameters[i].duration, frame->duration());
         EXPECT_EQ(frameParameters[i].hasAlpha, frame->hasAlpha());
     }
+
+    EXPECT_EQ(ARRAY_SIZE(frameParameters), decoder->frameCount());
+    EXPECT_EQ(cAnimationLoopInfinite, decoder->repetitionCount());
+}
+
+TEST_F(AnimatedWebPTests, verifyAnimationParametersBlendOverwrite)
+{
+    OwnPtr<WEBPImageDecoder> decoder = createDecoder();
+    EXPECT_EQ(cAnimationLoopOnce, decoder->repetitionCount());
+
+    RefPtr<SharedBuffer> data = readFile("/LayoutTests/fast/images/resources/webp-animated-no-blend.webp");
+    ASSERT_TRUE(data.get());
+    decoder->setData(data.get(), true);
+
+    const int canvasWidth = 94;
+    const int canvasHeight = 87;
+    const struct AnimParam {
+        int xOffset, yOffset, width, height;
+        ImageFrame::DisposalMethod disposalMethod;
+        ImageFrame::AlphaBlendSource alphaBlendSource;
+        unsigned duration;
+        bool hasAlpha;
+    } frameParameters[] = {
+        { 4, 10, 33, 32, ImageFrame::DisposeOverwriteBgcolor, ImageFrame::BlendAtopBgcolor, 1000u, true },
+        { 34, 30, 33, 32, ImageFrame::DisposeOverwriteBgcolor, ImageFrame::BlendAtopBgcolor, 1000u, true },
+        { 62, 50, 32, 32, ImageFrame::DisposeOverwriteBgcolor, ImageFrame::BlendAtopBgcolor, 1000u, true },
+        { 10, 54, 32, 33, ImageFrame::DisposeOverwriteBgcolor, ImageFrame::BlendAtopBgcolor, 1000u, true },
+    };
+
+    for (size_t i = 0; i < ARRAY_SIZE(frameParameters); ++i) {
+        const ImageFrame* const frame = decoder->frameBufferAtIndex(i);
+        EXPECT_EQ(ImageFrame::FrameComplete, frame->status());
+        EXPECT_EQ(canvasWidth, frame->getSkBitmap().width());
+        EXPECT_EQ(canvasHeight, frame->getSkBitmap().height());
+        EXPECT_EQ(frameParameters[i].xOffset, frame->originalFrameRect().x());
+        EXPECT_EQ(frameParameters[i].yOffset, frame->originalFrameRect().y());
+        EXPECT_EQ(frameParameters[i].width, frame->originalFrameRect().width());
+        EXPECT_EQ(frameParameters[i].height, frame->originalFrameRect().height());
+        EXPECT_EQ(frameParameters[i].disposalMethod, frame->disposalMethod());
+        EXPECT_EQ(frameParameters[i].alphaBlendSource, frame->alphaBlendSource());
+        EXPECT_EQ(frameParameters[i].duration, frame->duration());
+        EXPECT_EQ(frameParameters[i].hasAlpha, frame->hasAlpha());
+    }
 
     EXPECT_EQ(ARRAY_SIZE(frameParameters), decoder->frameCount());
     EXPECT_EQ(cAnimationLoopInfinite, decoder->repetitionCount());
 }
 
 TEST_F(AnimatedWebPTests, parseAndDecodeByteByByte)
 {
     const struct TestImage {
         const char* filename;
         unsigned frameCount;
@@ skipping 192 matching lines @@
     ImageFrame* firstFrame = decoder->frameBufferAtIndex(0);
     EXPECT_EQ(ImageFrame::FrameComplete, firstFrame->status());
     EXPECT_EQ(baselineHashes[0], hashSkBitmap(firstFrame->getSkBitmap()));
 }
 
 TEST_F(AnimatedWebPTests, decodeAfterReallocatingData)
 {
     testDecodeAfterReallocatingData("/LayoutTests/fast/images/resources/webp-animated.webp");
     testDecodeAfterReallocatingData("/LayoutTests/fast/images/resources/webp-animated-icc-xmp.webp");
 }