third_party/chromium/media/capture/video/shared_memory_buffer_tracker.h

// 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.

#ifndef MEDIA_CAPTURE_VIDEO_SHARED_MEMORY_BUFFER_TRACKER_H_
#define MEDIA_CAPTURE_VIDEO_SHARED_MEMORY_BUFFER_TRACKER_H_

#include "media/capture/video/video_capture_buffer_handle.h"
#include "media/capture/video/video_capture_buffer_tracker.h"

namespace gfx {
class Size;
}

namespace media {

// A tracker backed by unsafe shared memory. An unsafe region is necessary
// because a buffer may be used multiple times in an output media::VideoFrame to
// a decoder cross-process where it is written.
class SharedMemoryBufferTracker final : public VideoCaptureBufferTracker {
 public:
  SharedMemoryBufferTracker();

  SharedMemoryBufferTracker(const SharedMemoryBufferTracker&) = delete;
  SharedMemoryBufferTracker& operator=(const SharedMemoryBufferTracker&) =
      delete;

  ~SharedMemoryBufferTracker() override;

  // Implementation of VideoCaptureBufferTracker:
  bool Init(const gfx::Size& dimensions,
            VideoPixelFormat format,
            const mojom::PlaneStridesPtr& strides) override;
  bool IsReusableForFormat(const gfx::Size& dimensions,
                           VideoPixelFormat format,
                           const mojom::PlaneStridesPtr& strides) override;

  base::UnsafeSharedMemoryRegion DuplicateAsUnsafeRegion() override;
  mojo::ScopedSharedBufferHandle DuplicateAsMojoBuffer() override;
  std::unique_ptr<VideoCaptureBufferHandle> GetMemoryMappedAccess() override;
  gfx::GpuMemoryBufferHandle GetGpuMemoryBufferHandle() override;
  uint32_t GetMemorySizeInBytes() override;

 private:
  base::UnsafeSharedMemoryRegion region_;
  base::WritableSharedMemoryMapping mapping_;
};

}  // namespace media

#endif  // MEDIA_CAPTURE_VIDEO_SHARED_MEMORY_BUFFER_TRACKER_H_