Add a new API in WebMediaPlayer to do a GPU-GPU textures copy if possible

webkit/media/webmediaplayer_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/media/webmediaplayer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/message_loop_proxy.h"
 #include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/synchronization/waitable_event.h"
+#include "gpu/GLES2/gl2extchromium.h"
 #include "media/audio/null_audio_sink.h"
 #include "media/base/bind_to_loop.h"
 #include "media/base/filter_collection.h"
 #include "media/base/limits.h"
 #include "media/base/media_log.h"
 #include "media/base/pipeline.h"
 #include "media/base/video_frame.h"
 #include "media/filters/audio_renderer_impl.h"
 #include "media/filters/chunk_demuxer.h"
 #include "media/filters/video_renderer_base.h"
@@ skipping 635 matching lines @@
 void WebMediaPlayerImpl::putCurrentFrame(
     WebKit::WebVideoFrame* web_video_frame) {
   if (!accelerated_compositing_reported_) {
     accelerated_compositing_reported_ = true;
     DCHECK(frame_->view()->isAcceleratedCompositingActive());
     UMA_HISTOGRAM_BOOLEAN("Media.AcceleratedCompositingActive", true);
   }
   delete web_video_frame;
 }
 
+bool WebMediaPlayerImpl::copyVideoTextureToPlatformTexture(
+    WebKit::WebGraphicsContext3D* web_graphics_context,
+    unsigned int texture,
+    unsigned int level,
+    unsigned int internal_format,
+    bool premultiply_alpha,
+    bool flip_y) {
+  scoped_refptr<media::VideoFrame> video_frame;
+  {
+    base::AutoLock auto_lock(lock_);
+    video_frame = current_frame_;
+  }
+  if (video_frame &&
+      video_frame->format() == media::VideoFrame::NATIVE_TEXTURE &&
+      video_frame->texture_target() == GL_TEXTURE_2D) {
+    uint32 source_texture = video_frame->texture_id();
+    // The video is stored in a unmultiplied format, so premultiply
+    // if necessary.
+    web_graphics_context->pixelStorei(GL_UNPACK_PREMULTIPLY_ALPHA_CHROMIUM,
+        premultiply_alpha);
+    // Application itself needs to take care of setting the right flip_y
+    // value down to get the expected result.
+    // flip_y==true means to reverse the video orientation while
+    // flip_y==false means to keep the intrinsic orientation.
+    web_graphics_context->pixelStorei(GL_UNPACK_FLIP_Y_CHROMIUM, flip_y);
+    web_graphics_context->copyTextureCHROMIUM(GL_TEXTURE_2D,
+        source_texture, texture, level, internal_format);
+    web_graphics_context->pixelStorei(GL_UNPACK_FLIP_Y_CHROMIUM, false);
+    web_graphics_context->pixelStorei(GL_UNPACK_PREMULTIPLY_ALPHA_CHROMIUM,
+        false);
+    web_graphics_context->flush();

[Ken Russell (switch to Gerrit), 2013/03/12 02:08:13]

This flush shouldn't be necessary.

[Jun Jiang, 2013/03/12 13:38:38]

Could we keep the flush operation since the flush operation could bring some
performance gain? I have tried the cases to enable threaded-composting or
disable threaded-composting on win7, the performance is always better with the
flush operation added than without that.

[Ken Russell (switch to Gerrit), 2013/03/12 22:17:46]

Leaving it is fine, but please add a comment indicating that performance is
better with the flush than without it, and that that might warrant more
investigation.

+    return true;
+  }
+  return false;
+}
+
 // Helper enum for reporting generateKeyRequest/addKey histograms.
 enum MediaKeyException {
   kUnknownResultId,
   kSuccess,
   kKeySystemNotSupported,
   kInvalidPlayerState,
   kMaxMediaKeyException
 };
 
 static MediaKeyException MediaKeyExceptionForUMA(
@@ skipping 475 matching lines @@
 
   if (pending_repaint_)
     return;
 
   pending_repaint_ = true;
   main_loop_->PostTask(FROM_HERE, base::Bind(
       &WebMediaPlayerImpl::Repaint, AsWeakPtr()));
 }
 
 }  // namespace webkit_media