16 bpp video stream capture, render and createImageBitmap(video) using (CPU) shared memory buffers

cc/resources/video_resource_updater.cc

 // Copyright 2013 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 "cc/resources/video_resource_updater.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 410 matching lines @@
     case media::PIXEL_FORMAT_YUV420P12:
     case media::PIXEL_FORMAT_YUV422P12:
     case media::PIXEL_FORMAT_YUV444P12:
       bits_per_channel = 12;
       break;
     case media::PIXEL_FORMAT_Y16:
       bits_per_channel = 16;
       break;
   }
 
-  // TODO(dshwang): support PIXEL_FORMAT_Y16. crbug.com/624436
-  DCHECK_NE(bits_per_channel, 16);
-
-  // Only YUV software video frames are supported.
-  if (!media::IsYuvPlanar(input_frame_format)) {
-    NOTREACHED() << media::VideoPixelFormatToString(input_frame_format);
-    return VideoFrameExternalResources();
-  }
+  // Only YUV and Y16 software video frames are supported.
+  DCHECK(media::IsYuvPlanar(input_frame_format) ||
+         input_frame_format == media::PIXEL_FORMAT_Y16);
 
   const bool software_compositor = context_provider_ == NULL;
 
-  ResourceFormat output_resource_format =
-      resource_provider_->YuvResourceFormat(bits_per_channel);
+  ResourceFormat output_resource_format;
+  if (input_frame_format == media::PIXEL_FORMAT_Y16) {
+    // Unable to display directly as yuv planes so convert it to RGBA for
+    // compositing.
+    output_resource_format = RGBA_8888;
+  } else {
+    // Can be composited directly from yuv planes.
+    output_resource_format =
+        resource_provider_->YuvResourceFormat(bits_per_channel);
+  }
 
   // If GPU compositing is enabled, but the output resource format
   // returned by the resource provider is RGBA_8888, then a GPU driver
   // bug workaround requires that YUV frames must be converted to RGB
   // before texture upload.
   bool texture_needs_rgb_conversion =
       !software_compositor &&
       output_resource_format == ResourceFormat::RGBA_8888;
   size_t output_plane_count = media::VideoFrame::NumPlanes(input_frame_format);
 
@@ skipping 347 matching lines @@
   if (lost_resource) {
     resource_it->clear_refs();
     updater->DeleteResource(resource_it);
     return;
   }
 
   resource_it->remove_ref();
 }
 
 }  // namespace cc