webgl: optimize webgl.texSubImage2D(video) path.

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
index 33cce6b0aec3bf0ce5f711a30d53b3592f3aa381..bc4530093088fe64e30405e11407ec9b5deb049e 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
@@ -4384,7 +4384,7 @@ void WebGLRenderingContextBase::texImage2DCanvasByGPU(TexImageFunctionType funct
 
     if (!canvas->is3D()) {
         ImageBuffer* buffer = canvas->buffer();
-        if (!buffer->copyToPlatformTexture(webContext(), targetTexture, targetInternalformat, targetType,
+        if (!buffer->copyToPlatformTexture(webContext(), GL_TEXTURE_2D, targetTexture, targetInternalformat, targetType,
             targetLevel, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
             ASSERT_NOT_REACHED();
         }
@@ -4460,9 +4460,11 @@ void WebGLRenderingContextBase::texImage2D(GLenum target, GLint level, GLenum in
     // Otherwise, it will fall back to the normal SW path.
     WebGLTexture* texture = validateTextureBinding("texImage2D", target, true);
     ASSERT(texture);
-    if (GL_TEXTURE_2D == target) {
-        if (Extensions3DUtil::canUseCopyTextureCHROMIUM(target, internalformat, type, level)
-            && video->copyVideoTextureToPlatformTexture(webContext(), texture->object(), internalformat, type, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
+    if (Extensions3DUtil::canUseCopyTextureCHROMIUM(target, internalformat, type, level)) {
+        if (video->copyVideoTextureToPlatformTexture(webContext(),
+            WebMediaPlayer::CopyVideoTextureParams(
+                WebMediaPlayer::CopyVideoTextureParams::FullCopy, target, texture->object(),
+                internalformat, type, level, 0, 0, m_unpackPremultiplyAlpha, m_unpackFlipY))) {
             texture->setLevelInfo(target, level, internalformat, video->videoWidth(), video->videoHeight(), 1, type);
             return;
         }
@@ -4479,7 +4481,7 @@ void WebGLRenderingContextBase::texImage2D(GLenum target, GLint level, GLenum in
                 imageBuffer->canvas()->flush();
 
                 // This is a straight GPU-GPU copy, any necessary color space conversion was handled in the paintCurrentFrameInContext() call.
-                if (imageBuffer->copyToPlatformTexture(webContext(), texture->object(), internalformat, type,
+                if (imageBuffer->copyToPlatformTexture(webContext(), target, texture->object(), internalformat, type,
                     level, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
                     texture->setLevelInfo(target, level, internalformat, video->videoWidth(), video->videoHeight(), 1, type);
                     return;
@@ -4701,6 +4703,38 @@ void WebGLRenderingContextBase::texSubImage2D(GLenum target, GLint level, GLint
         || !validateTexFunc("texSubImage2D", TexSubImage2D, SourceHTMLVideoElement, target, level, 0, video->videoWidth(), video->videoHeight(), 0, format, type, xoffset, yoffset))
         return;
 
+    // Go through the fast path doing a GPU-GPU textures copy without a readback to system memory if possible.
+    // Otherwise, it will fall back to the normal SW path.
+    WebGLTexture* texture = validateTextureBinding("texSubImage2D", target, true);
+    ASSERT(texture);
+    if (Extensions3DUtil::canUseCopyTextureCHROMIUM(target, GL_RGBA, type, level)) {

[Ken Russell (switch to Gerrit), 2015/10/25 01:08:40]

It would be great if more code could be shared between here and texImage2D,
above, since the main difference now seems to be the arguments to the
CopyVideoTextureParams constructor.

[dshwang, 2015/10/26 14:17:32]

I'll merge soon.

[dshwang, 2015/10/26 17:45:15]

Done.

+        if (video->copyVideoTextureToPlatformTexture(webContext(),
+            WebMediaPlayer::CopyVideoTextureParams(
+                WebMediaPlayer::CopyVideoTextureParams::SubCopy, target, texture->object(),
+                GL_FALSE, GL_FALSE, level, xoffset, yoffset, m_unpackPremultiplyAlpha, m_unpackFlipY))) {
+            return;
+        }
+
+        // Try using an accelerated image buffer, this allows YUV conversion to be done on the GPU.
+        OwnPtr<ImageBufferSurface> surface = adoptPtr(new AcceleratedImageBufferSurface(IntSize(video->videoWidth(), video->videoHeight())));
+        if (surface->isValid()) {
+            OwnPtr<ImageBuffer> imageBuffer(ImageBuffer::create(surface.release()));
+            if (imageBuffer) {
+                // The video element paints an RGBA frame into our surface here. By using an AcceleratedImageBufferSurface,
+                // we enable the WebMediaPlayer implementation to do any necessary color space conversion on the GPU (though it
+                // may still do a CPU conversion and upload the results).
+                video->paintCurrentFrame(imageBuffer->canvas(), IntRect(0, 0, video->videoWidth(), video->videoHeight()), nullptr);
+                imageBuffer->canvas()->flush();
+
+                // This is a straight GPU-GPU copy, any necessary color space conversion was handled in the paintCurrentFrameInContext() call.
+                if (imageBuffer->copySubToPlatformTexture(webContext(), target, texture->object(), level,
+                    xoffset, yoffset, video->videoWidth(), video->videoHeight(), m_unpackPremultiplyAlpha, m_unpackFlipY)) {
+                    return;
+                }
+            }
+        }
+    }
+
     RefPtr<Image> image = videoFrameToImage(video);
     if (!image)
         return;