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

cc/resources/video_resource_updater.cc

Index: cc/resources/video_resource_updater.cc
diff --git a/cc/resources/video_resource_updater.cc b/cc/resources/video_resource_updater.cc
index 9fe434f3837211b63d4ded74b8b39ced0a398b20..3b5bed2ac65e495879a72ac39dc3464351be3239 100644
--- a/cc/resources/video_resource_updater.cc
+++ b/cc/resources/video_resource_updater.cc
@@ -358,11 +358,9 @@ VideoFrameExternalResources VideoResourceUpdater::CreateForSoftwarePlanes(
       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)) {
+  // Only YUV and Y16 software video frames are supported.
+  const bool isYuvPlanar = media::IsYuvPlanar(input_frame_format);
+  if (!(isYuvPlanar || input_frame_format == media::PIXEL_FORMAT_Y16)) {
     NOTREACHED() << media::VideoPixelFormatToString(input_frame_format);
     return VideoFrameExternalResources();
   }
@@ -370,7 +368,8 @@ VideoFrameExternalResources VideoResourceUpdater::CreateForSoftwarePlanes(
   const bool software_compositor = context_provider_ == NULL;
 
   ResourceFormat output_resource_format =
-      resource_provider_->YuvResourceFormat(bits_per_channel);
+      isYuvPlanar ? resource_provider_->YuvResourceFormat(bits_per_channel)

[aleksandar.stojiljkovic, 2016/10/20 21:52:49]

Check above only allows Yuv and Y16, so ResourceFormat::RGBA_8888 is the same as
if checking Y16, at least for now.
In following patches, the plan is to add also Y8 but this line wouldn't change -
Y8 would either use the same as lowbit YUV (R8) or RGBA_8888 here.
GPU buffer support is part of original patch and it is planned to submit it
later, once the discussion about what GPU format to use for Y16 is over.

+                  : ResourceFormat::RGBA_8888;
 
   // If GPU compositing is enabled, but the output resource format
   // returned by the resource provider is RGBA_8888, then a GPU driver