H264 HW encode using MediaFoundation

media/gpu/media_foundation_video_encode_accelerator_win.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 CONTENT_COMMON_GPU_MEDIA_MEDIA_FOUNDATION_VIDEO_ENCODE_ACCELERATOR_H_
+#define CONTENT_COMMON_GPU_MEDIA_MEDIA_FOUNDATION_VIDEO_ENCODE_ACCELERATOR_H_
+
+#include <mfapi.h>
+#include <mfidl.h>
+#include <strmif.h>
+
+#include "base/threading/thread_checker.h"
+#include "base/win/scoped_comptr.h"
+#include "base/win/windows_version.h"
+#include "media/gpu/media_gpu_export.h"
+#include "media/video/video_encode_accelerator.h"
+
+namespace media {
+
+class MEDIA_GPU_EXPORT MediaFoundationVideoEncodeAccelerator

[ananta, 2016/06/28 22:50:01]

Please add some documentation on what the threading model of this class looks
like, i.e. which methods are queued to worker threads and how the whole thing is
synchronized, etc.

[emircan, 2016/07/02 00:07:38]

Done.

+    : public media::VideoEncodeAccelerator {
+ public:
+  MediaFoundationVideoEncodeAccelerator();
+  ~MediaFoundationVideoEncodeAccelerator() override;
+
+  // media::VideoEncodeAccelerator implementation.
+  media::VideoEncodeAccelerator::SupportedProfiles GetSupportedProfiles()
+      override;
+  bool Initialize(media::VideoPixelFormat input_format,
+                  const gfx::Size& input_visible_size,
+                  media::VideoCodecProfile output_profile,
+                  uint32_t initial_bitrate,
+                  Client* client) override;
+  void Encode(const scoped_refptr<media::VideoFrame>& frame,
+              bool force_keyframe) override;
+  void UseOutputBitstreamBuffer(const media::BitstreamBuffer& buffer) override;
+  void RequestEncodingParametersChange(uint32_t bitrate,
+                                       uint32_t framerate) override;
+  void Destroy() override;
+
+ private:
+  // Holds output buffers coming from the client ready to be filled.
+  struct BitstreamBufferRef;
+
+  // Encoding tasks to be run on |encoder_thread_|.
+  void EncodeTask(const scoped_refptr<media::VideoFrame>& frame,
+                  bool force_keyframe);
+  void ProcessOutput();

[ananta, 2016/06/28 22:50:01]

Please add newlines between the functions.

[emircan, 2016/07/02 00:07:38]

Done.

+  void UseOutputBitstreamBufferTask(

[ananta, 2016/06/28 22:50:01]

Some commentary about what these functions do would be very helpful for future
reference.

[emircan, 2016/07/02 00:07:38]

Done.

+      std::unique_ptr<BitstreamBufferRef> buffer_ref);
+  void RequestEncodingParametersChangeTask(uint32_t bitrate,
+                                           uint32_t framerate);
+  void DestroyTask();
+
+  // Bitstream buffers ready to be used to return encoded output as a FIFO.
+  std::deque<std::unique_ptr<BitstreamBufferRef>> bitstream_buffer_queue_;
+
+  base::win::Version win_version_;

[ananta, 2016/06/28 22:50:01]

Why do you need to save the version?

[emircan, 2016/07/02 00:07:38]

Removed.

+  gfx::Size input_visible_size_;
+  size_t bitstream_buffer_size_;
+  int32_t frame_rate_;
+  int32_t target_bitrate_;
+  size_t u_plane_offset_;
+  size_t v_plane_offset_;
+
+  // Our original calling task runner for the child thread.
+  const scoped_refptr<base::SingleThreadTaskRunner> client_task_runner_;
+
+  // To expose client callbacks from VideoEncodeAccelerator.
+  // NOTE: all calls to this object *MUST* be executed on
+  // |client_task_runner_|.
+  base::WeakPtr<Client> client_;
+  std::unique_ptr<base::WeakPtrFactory<Client>> client_ptr_factory_;
+
+  base::win::ScopedComPtr<IMFTransform> encoder_;
+  base::win::ScopedComPtr<ICodecAPI> codec_api_;
+
+  DWORD input_stream_count_min_;
+  DWORD input_stream_count_max_;
+  DWORD output_stream_count_min_;
+  DWORD output_stream_count_max_;
+
+  base::win::ScopedComPtr<IMFSample> input_sample_;
+  base::win::ScopedComPtr<IMFSample> output_sample_;
+
+  // Thread checker to enforce that this object is used on a specific thread.
+  // It is pinned on |client_task_runner_| thread.
+  base::ThreadChecker thread_checker_;
+
+  // This thread services tasks posted from the VEA API entry points by the
+  // GPU child thread and CompressionCallback() posted from device thread.
+  base::Thread encoder_thread_;
+  scoped_refptr<base::SingleThreadTaskRunner> encoder_thread_task_runner_;
+
+  // Declared last to ensure that all weak pointers are invalidated before
+  // other destructors run.
+  base::WeakPtr<MediaFoundationVideoEncodeAccelerator> encoder_weak_ptr_;
+  base::WeakPtrFactory<MediaFoundationVideoEncodeAccelerator>
+      encoder_task_weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaFoundationVideoEncodeAccelerator);
+};
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_MEDIA_FOUNDATION_VIDEO_ENCODE_ACCELERATOR_H_