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 executed in the GPU process. It takes decoding requests from
+// ARC via IPC channels and translates and sends those requests to an
+// implementation of media::VideoDecodeAccelerator. It also returns the decoded
+// frames back to the ARC side.
+class ArcGpuVideoDecodeAccelerator
+    : public ArcVideoAccelerator,
+      public media::VideoDecodeAccelerator::Client,
+      public base::SupportsWeakPtr<ArcGpuVideoDecodeAccelerator> {
+ public:
+  ArcGpuVideoDecodeAccelerator();
+  ~ArcGpuVideoDecodeAccelerator() override;
+
+  // Implementation of the ArcVideoAccelerator interface.
+  bool Initialize(const Config& config,
+                  ArcVideoAccelerator::Client* client) override;
+  void SetNumberOfOutputBuffers(size_t number) override;
+  void BindSharedMemory(PortType port,
+                        uint32_t index,
+                        int ashmem_fd,
+                        off_t offset,
+                        size_t length) override;
+  void 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:
+  // Some information related to a bitstream buffer. The information is required
+  // when input or output buffers are returned back to the client.
+  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);
+  };
+
+  // The information about the shared memory used as an input buffer.
+  struct InputBufferInfo {
+    // The file handle to access the buffer. It is owned by this class and
+    // should be closed after use.
+    base::ScopedFD handle;
+    off_t offset = 0;
+    size_t length = 0;
+  };
+
+  // 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 function to validate |port| and |index|.
+  bool ValidatePortAndIndex(PortType port, uint32_t index);
+
+  // Creates an 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 CreateInputRecord(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);
+
+  // When true, an EOS output buffer need to be sent to |arc_client_| once an
+  // output buffer is available.
+  bool pending_eos_output_buffer_;
+
+  scoped_ptr<media::VideoDecodeAccelerator> vda_;
+
+  // It's safe to use the pointer here, the life cycle of the |arc_client_|
+  // is longer than this ArcGpuVideoDecodeAccelerator.
+  ArcVideoAccelerator::Client* arc_client_;
+
+  // The next ID for the bitstream buffer, started from 0.
+  int32_t next_bitstream_buffer_id_;
+
+  gfx::Size coded_size_;
+
+  // The |picture_buffer_id|s 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 (if
+  // not empty), marked with an EOS flag, to |arc_client_|, and return the rest
+  // to VDA for reuse.
+  std::queue<int32_t> buffers_pending_eos_;
+
+  // A list of most recent |kMaxNumberOfInputRecord| InputRecords.
+  // |kMaxNumberOfInputRecord| is defined in the cc file.
+  std::list<InputRecord> input_records_;
+
+  // The details of the shared memory of each input buffers.
+  std::vector<InputBufferInfo> input_buffer_info_;
+
+  // To keep those output buffers which have been bound by bindDmabuf() but not
+  // be used yet. Will call VDA::ImportBufferForPicture() when those buffers are
+  // used for the first time.
+  std::vector<base::ScopedFD> buffers_pending_import_;
+
+  base::ThreadChecker thread_checker_;
+  size_t output_buffer_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcGpuVideoDecodeAccelerator);
+};
+
+}  // namespace arc
+}  // namespace chromeos
+
+#endif  // CHROME_GPU_ARC_GPU_VIDEO_DECODE_ACCELERATOR_H_