Add ArcGpuVideoDecodeAccelerator.

chrome/gpu/arc_gpu_video_decode_accelerator.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 CHROME_GPU_ARC_GPU_VIDEO_DECODE_ACCELERATOR_H_
+#define CHROME_GPU_ARC_GPU_VIDEO_DECODE_ACCELERATOR_H_
+
+#include <list>
+#include <queue>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "chrome/gpu/arc_video_accelerator.h"
+#include "media/video/video_decode_accelerator.h"
+
+namespace chromeos {
+namespace arc {
+
+// This class is excuted in Chromium's GPU process. It takes decoding requests

[Pawel Osciak, 2016/02/29 08:25:20]

s/excuted/executed/

[Owen Lin, 2016/03/03 06:30:43]

Done.

+// from ARC via IPC channels and translates and send those requests to the
+// real VDA on Chromium. It also returns the decoded frames back to the

[Pawel Osciak, 2016/02/29 08:25:21]

s/real VDA/to an implementation of the VideoDecodeAccelerator interface/

[Owen Lin, 2016/03/03 06:30:43]

Done.

+// ARC side.
+class ArcGpuVideoDecodeAccelerator
+    : public ArcVideoAccelerator,
+      public media::VideoDecodeAccelerator::Client,
+      public base::SupportsWeakPtr<ArcGpuVideoDecodeAccelerator> {
+ public:
+  ArcGpuVideoDecodeAccelerator(
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner);
+  ~ArcGpuVideoDecodeAccelerator() override;
+
+  // Implementation of the ArcVideoAccelerator interface.
+  bool Initialize(DeviceType device_type,
+                  ArcVideoAccelerator::Client* client) override;
+  bool SetBufferCount(PortType port, size_t* count) override;
+  bool SetBufferFormat(PortType port, const BufferFormat& format) override;
+  bool BindSharedMemory(PortType port,

[Pawel Osciak, 2016/02/29 08:25:20]

Could we make all calls (apart from perhaps Initialize()) void and report errors
instead please?

[Owen Lin, 2016/03/03 06:30:43]

The reason is? Let's make BindSharedMemory void, but due to the current logic in
ArcCodec, it is not possible to let SetBufferCount returns void.

+                        uint32_t index,
+                        int ashmem_fd,
+                        size_t offset,
+                        size_t length) override;
+  bool BindDmabuf(PortType port, uint32_t index, int dmabuf_fd) override;
+  void UseBuffer(PortType port,
+                 uint32_t index,
+                 const BufferMetadata& metadata) override;
+  void Reset() override;
+
+  // Implementation of the VideoDecodeAccelerator::Client interface.
+  void ProvidePictureBuffers(uint32_t requested_num_of_buffers,
+                             const gfx::Size& dimensions,
+                             uint32_t texture_target) override;
+  void DismissPictureBuffer(int32_t picture_buffer) override;
+  void PictureReady(const media::Picture& picture) override;
+  void NotifyEndOfBitstreamBuffer(int32_t bitstream_buffer_id) override;
+  void NotifyFlushDone() override;
+  void NotifyResetDone() override;
+  void NotifyError(media::VideoDecodeAccelerator::Error error) override;
+
+ private:
+  struct InputRecord {
+    int32_t bitstream_buffer_id;
+    uint32_t buffer_index;
+    int64_t timestamp;
+
+    InputRecord(int32_t bitstream_buffer_id,
+                uint32_t buffer_index,
+                int64_t timestamp);
+  };
+
+  struct InputBufferInfo {
+    // The file handle to access the buffer. It is owned by this ArcGVDA and

[Pawel Osciak, 2016/02/29 08:25:21]

s/ArcGVDA/class/

[Owen Lin, 2016/03/03 06:30:43]

Done.

+    // should be freed if not used.

[Pawel Osciak, 2016/02/29 08:25:20]

s/freed if not used/closed after use/

[Owen Lin, 2016/03/03 06:30:43]

Done.

+    base::ScopedFD handle;
+    off_t offset;
+    size_t length;
+
+    InputBufferInfo();
+    InputBufferInfo(InputBufferInfo&&);
+    ~InputBufferInfo();
+  };
+
+  struct PortInfo {
+    MemoryType memory_type;
+    size_t num_buffers;
+
+    PortInfo();
+  };
+
+  // Helper function to Send the end-of-stream output buffer if
+  // |pending_eos_output_buffer_| is true, or reuse the picture in ArcVDA.
+  void SendEosIfNeededOrReusePicture(uint32_t index);
+
+  // Helper functions to validate |port| (and |index|).
+  bool ValidatePort(PortType port);
+  bool ValidatePortAndIndex(PortType port, uint32_t index);
+
+  // Indicates a pending EOS output buffer. When it is true, an EOS output

[Pawel Osciak, 2016/02/29 08:25:20]

s/Indicates a pending EOS output buffer. When it is true,/When true,/

[Owen Lin, 2016/03/03 06:30:43]

Done.

+  // buffer need to be sent to |arc_client_| once an output buffer is available.
+  bool pending_eos_output_buffer_;

[Pawel Osciak, 2016/02/29 08:25:20]

Please move members to after methods.

[Owen Lin, 2016/03/03 06:30:43]

Done.

+  scoped_ptr<media::VideoDecodeAccelerator> vda_;
+
+  // Sets InputRecord for the given |bitstream_buffer_id|. The |buffer_index|
+  // is the index of the associated input buffer. The |timestamp| is the
+  // time the video frame should be displayed.
+  void SetInputRecord(int32_t bitstream_buffer_id,
+                      uint32_t buffer_index,
+                      int64_t timestamp);
+
+  // Finds the InputRecord which matches to given |bitstream_buffer_id|.
+  // Returns |nullptr| if it cannot be found.
+  InputRecord* FindInputRecord(int32_t bitstream_buffer_id);
+
+  // It's safe to use the pointer here, the life cycle of the |arc_client_|
+  // is longer than this ArcGpuVideoDecodeAccelerator.
+  ArcVideoAccelerator::Client* arc_client_;

[Pawel Osciak, 2016/02/29 08:25:20]

We could perhaps use WeakPtr here...

[Owen Lin, 2016/03/03 06:30:43]

Not so sure, WeakPtr somehow means we expect it to be vanished, but it should
not.

+
+  // The callback called when reset completes.
+  base::Closure reset_done_callback_;
+
+  PortInfo port_info_[PORT_COUNT];

[Pawel Osciak, 2016/02/29 08:25:21]

Unless I'm missing something, we are not using memory_type from PortInfo, and
num_buffers could be taken from input_buffer_info_.size(), and we could remove
this struct and array?

[Owen Lin, 2016/03/03 06:30:43]

Done.

+
+  // The next ID for the bitstream buffer, started from 0.
+  int32_t next_bitstream_buffer_id_;
+
+  gfx::Size coded_size_;
+
+  // The index of buffers returned while Flushing, will be used for sending

[Pawel Osciak, 2016/02/29 08:25:20]

picture_buffer_ids for Pictures that were returned to us from VDA via
PictureReady() while flushing. We keep them until NotifyFlushDone(); once it's
called, we send one of the pending buffers from this queue, marked with an EOS
flag, to arc_client_, and return the rest to VDA for reuse.

[Owen Lin, 2016/03/03 06:30:43]

Done.

+  // EOS buffer back to |arc_client_|.
+  std::queue<uint32_t> buffers_pending_eos_;
+  std::list<InputRecord> input_records_;
+  std::vector<InputBufferInfo> input_buffer_info_;
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+  base::ThreadChecker thread_checker_;
+  size_t output_buffer_size_;
+};

[Pawel Osciak, 2016/02/29 08:25:21]

Do we need DISALLOW_IMPLICIT_CONSTRUCTORS()?

[Owen Lin, 2016/03/03 06:30:43]

Done.

+
+}  // namespace arc
+}  // namespace chromeos
+
+#endif  // CHROME_GPU_ARC_GPU_VIDEO_DECODE_ACCELERATOR_H_