Mojo Video Capture service in media/capture

media/capture/service/mojo_video_frame.cc

+// Copyright 2016 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 "media/capture/service/mojo_video_frame.h"
+
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace media {
+
+// static
+scoped_refptr<MojoVideoFrame> MojoVideoFrame::CreateMojoVideoFrame(
+    const gfx::Size& dimensions,
+    base::TimeDelta timestamp) {
+  scoped_refptr<MojoVideoFrame> frame =
+      new MojoVideoFrame(dimensions, timestamp);
+  return frame->Init() ? frame : nullptr;
+}
+
+MojoVideoFrame::MojoVideoFrame(const gfx::Size& dimensions,
+                               base::TimeDelta timestamp)
+    : VideoFrame(media::PIXEL_FORMAT_I420,
+                 STORAGE_UNOWNED_MEMORY,
+                 dimensions,
+                 gfx::Rect(dimensions),
+                 dimensions,
+                 timestamp),
+      shared_buffer_size_(
+          media::VideoFrame::AllocationSize(media::PIXEL_FORMAT_I420,
+                                            dimensions)),
+      shared_buffer_(shared_buffer_size_) {
+  DCHECK(shared_buffer_size_ > 0);
+  DCHECK(shared_buffer_.handle.is_valid());
+}
+
+bool MojoVideoFrame::Init() {
+  CHECK_EQ(format(), media::PIXEL_FORMAT_I420);
+  // Map our |shared_buffer_| and plug the pointers into |data_|.
+  // TODO(mcasas): This step usually needs alignment, e.g. base::AlignedAlloc()
+  void* memory = nullptr;
+  const MojoResult rv =
+      mojo::MapBuffer(shared_buffer_.handle.get(), 0 /* offset */,
+                      shared_buffer_size_, &memory, 0 /* flags */);
+  if (rv != MOJO_RESULT_OK || !memory)
+    return false;
+
+  const auto dimensions = coded_size();
+
+  set_stride(kYPlane, dimensions.width());
+  set_stride(kUPlane, dimensions.width() / 2);
+  set_stride(kVPlane, dimensions.width() / 2);
+  set_data(kYPlane, static_cast<uint8_t*>(memory));
+  set_data(kUPlane, static_cast<uint8_t*>(memory) + dimensions.GetArea());
+  set_data(kVPlane,
+           static_cast<uint8_t*>(memory) + (dimensions.GetArea() * 5 / 4));
+
+  return true;
+};
+
+MojoVideoFrame::~MojoVideoFrame() {}
+
+}  // namespace media