ExynosVideoEncodeAccelerator

content/common/gpu/media/exynos_video_encode_accelerator.h

+// Copyright (c) 2013 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_EXYNOS_VIDEO_ENCODE_ACCELERATOR_H_
+#define CONTENT_COMMON_GPU_MEDIA_EXYNOS_VIDEO_ENCODE_ACCELERATOR_H_
+
+#include <list>
+#include <vector>
+
+#include "base/memory/linked_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread.h"
+#include "media/video/video_encode_accelerator.h"
+#include "ui/gfx/size.h"
+
+namespace base {
+
+class MessageLoopProxy;
+
+}  // namespace base
+
+namespace media {
+
+class BitstreamBuffer;
+
+}  // namespace media
+
+namespace content {
+
+// This class handles Exynos video encode acceleration by interfacing with the
+// V4L2 devices exported by the Multi Format Codec and GScaler hardware blocks
+// on the Exynos platform.  The threading model of this class is the same as the
+// ExynosVideoDecodeAccelerator (from which class this was designed).
+class ExynosVideoEncodeAccelerator : public media::VideoEncodeAccelerator {
+ public:
+  explicit ExynosVideoEncodeAccelerator(
+      media::VideoEncodeAccelerator::Client* client);
+  virtual ~ExynosVideoEncodeAccelerator();
+
+  // media::VideoEncodeAccelerator implementation.
+  virtual void Initialize(media::VideoFrame::Format format,
+                          const gfx::Size& input_visible_size,
+                          media::VideoCodecProfile output_profile,
+                          uint32 initial_bitrate) OVERRIDE;
+  virtual void Encode(const scoped_refptr<media::VideoFrame>& frame,
+                      bool force_keyframe) OVERRIDE;
+  virtual void UseOutputBitstreamBuffer(
+      const media::BitstreamBuffer& buffer) OVERRIDE;
+  virtual void RequestEncodingParametersChange(uint32 bitrate,
+                                               uint32 framerate) OVERRIDE;
+  virtual void Destroy() OVERRIDE;
+
+  static std::vector<media::VideoEncodeAccelerator::SupportedProfile>
+      GetSupportedProfiles();
+
+ private:
+  // Auto-destroy reference for BitstreamBuffer, for tracking buffers passed to
+  // this instance.
+  struct BitstreamBufferRef;
+
+  // Record for GSC input buffers.
+  struct GscInputRecord {
+    GscInputRecord();
+    bool at_device;
+    scoped_refptr<media::VideoFrame> frame;
+  };
+
+  // Record for GSC output buffers.
+  struct GscOutputRecord {
+    GscOutputRecord();
+    bool at_device;
+    int mfc_input;
+  };
+
+  // Record for MFC input buffers.
+  struct MfcInputRecord {
+    MfcInputRecord();
+    bool at_device;
+    int fd[2];
+  };
+
+  // Record for MFC output buffers.
+  struct MfcOutputRecord {
+    MfcOutputRecord();
+    bool at_device;
+    linked_ptr<BitstreamBufferRef> buffer_ref;
+  };
+
+  enum {
+    kInitialFramerate = 30,
+    // These are rather subjectively tuned.
+    kGscInputBufferCount = 2,
+    kGscOutputBufferCount = 2,
+    kMfcOutputBufferCount = 2,
+    // MFC hardware does not report required output buffer size correctly.
+    // Use maximum theoretical size to avoid hanging the hardware.
+    kMfcOutputBufferSize = (2 * 1024 * 1024),
+  };
+
+  // Internal state of the encoder.
+  enum State {
+    kUninitialized,  // Initialize() not yet called.
+    kInitialized,    // Initialize() returned true; ready to start encoding.
+    kEncoding,       // Encoding frames.
+    kError,          // Error in encoder state.
+  };
+
+  //
+  // Encoding tasks, to be run on encode_thread_.
+  //
+
+  // Encode a GSC input buffer.
+  void EncodeTask(const scoped_refptr<media::VideoFrame>& frame,
+                  bool force_keyframe);
+
+  // Add a BitstreamBuffer to the queue of buffers ready to be used for encoder
+  // output.
+  void UseOutputBitstreamBufferTask(scoped_ptr<BitstreamBufferRef> buffer_ref);
+
+  // Device destruction task.
+  void DestroyTask();
+
+  // Service I/O on the V4L2 devices.  This task should only be scheduled from
+  // DevicePollTask().
+  void ServiceDeviceTask();
+
+  // Handle the various device queues.
+  void EnqueueGsc();
+  void DequeueGsc();
+  void EnqueueMfc();
+  void DequeueMfc();
+  // Enqueue a buffer on the corresponding queue.  Returns false on fatal error.
+  bool EnqueueGscInputRecord();
+  bool EnqueueGscOutputRecord();
+  bool EnqueueMfcInputRecord();
+  bool EnqueueMfcOutputRecord();
+
+  // Attempt to start/stop device_poll_thread_.
+  bool StartDevicePoll();
+  bool StopDevicePoll();
+  // Set/clear the device poll interrupt (using device_poll_interrupt_fd_).
+  bool SetDevicePollInterrupt();
+  bool ClearDevicePollInterrupt();
+
+  //
+  // Device tasks, to be run on device_poll_thread_.
+  //
+
+  // The device task.
+  void DevicePollTask(unsigned int poll_fds);
+
+  //
+  // Safe from any thread.
+  //
+
+  // Error notification (using PostTask() to child thread, if necessary).
+  void NotifyError(Error error);
+
+  // Set the encoder_thread_ state (using PostTask to encoder thread, if
+  // necessary).
+  void SetEncoderState(State state);
+
+  //
+  // Other utility functions.  Called on encoder_thread_, unless
+  // encoder_thread_ is not yet started, in which case the child thread can call
+  // these (e.g. in Initialize() or Destroy()).
+  //
+
+  // Change the parameters of encoding.
+  void RequestEncodingParametersChangeTask(uint32 bitrate, uint32 framerate);
+
+  // Create the buffers we need.
+  bool CreateGscInputBuffers();
+  bool CreateGscOutputBuffers();
+  bool SetMfcFormats();
+  bool CreateMfcInputBuffers();
+  bool CreateMfcOutputBuffers();
+
+  // Destroy these buffers.
+  void DestroyGscInputBuffers();
+  void DestroyGscOutputBuffers();
+  void DestroyMfcInputBuffers();
+  void DestroyMfcOutputBuffers();
+
+  // Our original calling message loop for the child thread.
+  const scoped_refptr<base::MessageLoopProxy> child_message_loop_proxy_;
+
+  // WeakPtr<> pointing to |this| for use in posting tasks from the encoder or
+  // device worker threads back to the child thread.  Because the worker threads
+  // are members of this class, any task running on those threads is guaranteed
+  // that this object is still alive.  As a result, tasks posted from the child
+  // thread to the encoder or device thread should use base::Unretained(this),
+  // and tasks posted the other way should use |weak_this_|.
+  base::WeakPtrFactory<ExynosVideoEncodeAccelerator> weak_this_ptr_factory_;
+  base::WeakPtr<ExynosVideoEncodeAccelerator> weak_this_;
+
+  // To expose client callbacks from VideoEncodeAccelerator.
+  // NOTE: all calls to these objects *MUST* be executed on
+  // child_message_loop_proxy_.
+  base::WeakPtrFactory<Client> client_ptr_factory_;
+  base::WeakPtr<Client> client_;
+
+  //
+  // Encoder state, owned and operated by encoder_thread_.
+  // Before encoder_thread_ has started, the encoder state is managed by
+  // the child (main) thread.  After encoder_thread_ has started, the encoder
+  // thread should be the only one managing these.
+  //
+
+  // This thread services tasks posted from the VEA API entry points by the
+  // child thread and device service callbacks posted from the device thread.
+  base::Thread encoder_thread_;
+  // Encoder state.
+  State encoder_state_;
+  // The visible/allocated sizes of the input frame.
+  gfx::Size input_visible_size_;
+  gfx::Size input_allocated_size_;
+  // The visible/allocated sizes of the color-converted intermediate frame.
+  gfx::Size converted_visible_size_;
+  gfx::Size converted_allocated_size_;
+  // The logical visible size of the output frame.
+  gfx::Size output_visible_size_;
+  // The required byte size of output BitstreamBuffers.
+  size_t output_buffer_byte_size_;
+
+  // We need to provide the stream header with every keyframe, to allow
+  // midstream decoding restarts.  Store it here.
+  scoped_ptr<uint8[]> stream_header_;
+  size_t stream_header_size_;
+
+  // V4L2 formats for input frames and the output stream.
+  uint32 input_format_fourcc_;
+  uint32 output_format_fourcc_;
+
+  // Video frames ready to be encoded.
+  std::list<scoped_refptr<media::VideoFrame> > encoder_input_queue_;
+
+  // GSC color conversion device.
+  int gsc_fd_;
+  // GSC input queue state.
+  bool gsc_input_streamon_;
+  // GSC input buffers enqueued to device.
+  int gsc_input_buffer_queued_count_;
+  // GSC input buffers ready to use; LIFO since we don't care about ordering.
+  std::vector<int> gsc_free_input_buffers_;
+  // Mapping of int index to GSC input buffer record.
+  std::vector<GscInputRecord> gsc_input_buffer_map_;
+
+  // GSC output queue state.
+  bool gsc_output_streamon_;
+  // GSC output buffers enqueued to device.
+  int gsc_output_buffer_queued_count_;
+  // GSC output buffers ready to use; LIFO since we don't care about ordering.
+  std::vector<int> gsc_free_output_buffers_;
+  // Mapping of int index to GSC output buffer record.
+  std::vector<GscOutputRecord> gsc_output_buffer_map_;
+
+  // MFC input buffers filled by GSC, waiting to be queued to MFC.
+  std::list<int> mfc_ready_input_buffers_;
+
+  // MFC video encoding device.
+  int mfc_fd_;
+
+  // MFC input queue state.
+  bool mfc_input_streamon_;
+  // MFC input buffers enqueued to device.
+  int mfc_input_buffer_queued_count_;
+  // MFC input buffers ready to use; LIFO since we don't care about ordering.
+  std::vector<int> mfc_free_input_buffers_;
+  // Mapping of int index to MFC input buffer record.
+  std::vector<MfcInputRecord> mfc_input_buffer_map_;
+
+  // MFC output queue state.
+  bool mfc_output_streamon_;
+  // MFC output buffers enqueued to device.
+  int mfc_output_buffer_queued_count_;
+  // MFC output buffers ready to use; LIFO since we don't care about ordering.
+  std::vector<int> mfc_free_output_buffers_;
+  // Mapping of int index to MFC output buffer record.
+  std::vector<MfcOutputRecord> mfc_output_buffer_map_;
+
+  // Bitstream buffers ready to be used to return encoded output, as a LIFO
+  // since we don't care about ordering.
+  std::vector<linked_ptr<BitstreamBufferRef> > encoder_output_queue_;
+
+  //
+  // The device polling thread handles notifications of V4L2 device changes.
+  // TODO(sheu): replace this thread with an TYPE_IO encoder_thread_.
+  //
+
+  // The thread.
+  base::Thread device_poll_thread_;
+  // eventfd fd to signal device poll thread when its poll() should be
+  // interrupted.
+  int device_poll_interrupt_fd_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExynosVideoEncodeAccelerator);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_EXYNOS_VIDEO_ENCODE_ACCELERATOR_H_