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

media/base/video_frame.cc

Index: media/base/video_frame.cc
diff --git a/media/base/video_frame.cc b/media/base/video_frame.cc
index fd4788026434039525f9b5cdfe76c69210af25af..c486e1f82af28a3a2c6a9978a393586edd608d65 100644
--- a/media/base/video_frame.cc
+++ b/media/base/video_frame.cc
@@ -770,8 +770,9 @@ scoped_refptr<VideoFrame> VideoFrame::WrapExternalStorage(
 
   // TODO(miu): This function should support any pixel format.
   // http://crbug.com/555909
-  if (format != PIXEL_FORMAT_I420) {
-    LOG(DFATAL) << "Only PIXEL_FORMAT_I420 format supported: "
+  if (format != PIXEL_FORMAT_I420 && format != PIXEL_FORMAT_Y16) {
+    LOG(DFATAL) << "Only PIXEL_FORMAT_I420 and PIXEL_FORMAT_Y16 formats are"
+                   "supported: "
                 << VideoPixelFormatToString(format);
     return nullptr;
   }
@@ -792,16 +793,29 @@ scoped_refptr<VideoFrame> VideoFrame::WrapExternalStorage(
     frame = new VideoFrame(format, storage_type, coded_size, visible_rect,
                            natural_size, timestamp);
   }
-  frame->strides_[kYPlane] = coded_size.width();
-  // TODO(miu): This always rounds widths down, whereas VideoFrame::RowBytes()
-  // always rounds up.  This inconsistency must be resolved.  Perhaps a
-  // CommonAlignment() check should be made in IsValidConfig()?
-  // http://crbug.com/555909
-  frame->strides_[kUPlane] = coded_size.width() / 2;
-  frame->strides_[kVPlane] = coded_size.width() / 2;
-  frame->data_[kYPlane] = data;
-  frame->data_[kUPlane] = data + coded_size.GetArea();
-  frame->data_[kVPlane] = data + (coded_size.GetArea() * 5 / 4);
+  switch (NumPlanes(format)) {
+    case 0:
+    case 2:
+    case 4:
+      NOTREACHED();

[xhwang, 2016/10/27 16:59:18]

In prod, we are still returning a non-null frame here. Shall we just return
nullptr here instead?

[aleksandar.stojiljkovic, 2016/10/27 19:12:22]

Done. Replaced by LOG(DFATAL) and return nullptr, according to the handling in
l.774 and l.785.

+      break;
+    case 3:
+      DCHECK_EQ(format, PIXEL_FORMAT_I420);
+      // TODO(miu): This always rounds widths down, whereas
+      // VideoFrame::RowBytes() always rounds up.  This inconsistency must be
+      // resolved.  Perhaps a CommonAlignment() check should be made in
+      // IsValidConfig()?
+      // http://crbug.com/555909
+      frame->strides_[kVPlane] = coded_size.width() / 2;
+      frame->data_[kVPlane] = data + (coded_size.GetArea() * 5 / 4);
+      frame->strides_[kUPlane] = coded_size.width() / 2;
+      frame->data_[kUPlane] = data + coded_size.GetArea();
+    // Fall through.
+    case 1:
+      frame->strides_[kYPlane] = RowBytes(kYPlane, format, coded_size.width());
+      frame->data_[kYPlane] = data;
+      return frame;
+  }
   return frame;
 }
 
@@ -972,6 +986,7 @@ gfx::Size VideoFrame::SampleSize(VideoPixelFormat format, size_t plane) {
         case PIXEL_FORMAT_YUV444P9:
         case PIXEL_FORMAT_YUV444P10:
         case PIXEL_FORMAT_YUV444P12:
+        case PIXEL_FORMAT_Y16:
           return gfx::Size(1, 1);
 
         case PIXEL_FORMAT_YV16:
@@ -1000,7 +1015,6 @@ gfx::Size VideoFrame::SampleSize(VideoPixelFormat format, size_t plane) {
         case PIXEL_FORMAT_RGB32:
         case PIXEL_FORMAT_MJPEG:
         case PIXEL_FORMAT_Y8:
-        case PIXEL_FORMAT_Y16:
           break;
       }
   }