vda: Rename Exynos VDA to V4L2 VDA

content/common/gpu/media/exynos_video_decode_accelerator.h

-// Copyright (c) 2012 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.
-//
-// This file contains an implementation of VideoDecoderAccelerator
-// that utilizes the hardware video decoder present on the Exynos SoC.
-
-#ifndef CONTENT_COMMON_GPU_MEDIA_EXYNOS_VIDEO_DECODE_ACCELERATOR_H_
-#define CONTENT_COMMON_GPU_MEDIA_EXYNOS_VIDEO_DECODE_ACCELERATOR_H_
-
-#include <queue>
-#include <vector>
-
-#include "base/callback_forward.h"
-#include "base/memory/linked_ptr.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/threading/thread.h"
-#include "content/common/content_export.h"
-#include "content/common/gpu/media/video_decode_accelerator_impl.h"
-#include "media/base/limits.h"
-#include "media/base/video_decoder_config.h"
-#include "media/video/picture.h"
-#include "ui/gfx/size.h"
-#include "ui/gl/gl_bindings.h"
-
-namespace base {
-class MessageLoopProxy;
-}
-
-namespace content {
-class H264Parser;
-
-// This class handles Exynos video acceleration directly through the V4L2
-// device exported by the Multi Format Codec hardware block.
-//
-// The threading model of this class is driven by the fact that it needs to
-// interface two fundamentally different event queues -- the one Chromium
-// provides through MessageLoop, and the one driven by the V4L2 devices which
-// is waited on with epoll().  There are three threads involved in this class:
-//
-// * The child thread, which is the main GPU process thread which calls the
-//   media::VideoDecodeAccelerator entry points.  Calls from this thread
-//   generally do not block (with the exception of Initialize() and Destroy()).
-//   They post tasks to the decoder_thread_, which actually services the task
-//   and calls back when complete through the
-//   media::VideoDecodeAccelerator::Client interface.
-// * The decoder_thread_, owned by this class.  It services API tasks, through
-//   the *Task() routines, as well as V4L2 device events, through
-//   ServiceDeviceTask().  Almost all state modification is done on this thread.
-// * The device_poll_thread_, owned by this class.  All it does is epoll() on
-//   the V4L2 in DevicePollTask() and schedule a ServiceDeviceTask() on the
-//   decoder_thread_ when something interesting happens.
-//   TODO(sheu): replace this thread with an TYPE_IO decoder_thread_.
-//
-// Note that this class has no locks!  Everything's serviced on the
-// decoder_thread_, so there are no synchronization issues.
-// ... well, there are, but it's a matter of getting messages posted in the
-// right order, not fiddling with locks.
-class CONTENT_EXPORT ExynosVideoDecodeAccelerator
-    : public VideoDecodeAcceleratorImpl {
- public:
-  ExynosVideoDecodeAccelerator(
-      EGLDisplay egl_display,
-      Client* client,
-      const base::WeakPtr<Client>& io_client_,
-      const base::Callback<bool(void)>& make_context_current,
-      const scoped_refptr<base::MessageLoopProxy>& io_message_loop_proxy);
-  virtual ~ExynosVideoDecodeAccelerator();
-
-  // media::VideoDecodeAccelerator implementation.
-  // Note: Initialize() and Destroy() are synchronous.
-  virtual bool Initialize(media::VideoCodecProfile profile) OVERRIDE;
-  virtual void Decode(const media::BitstreamBuffer& bitstream_buffer) OVERRIDE;
-  virtual void AssignPictureBuffers(
-      const std::vector<media::PictureBuffer>& buffers) OVERRIDE;
-  virtual void ReusePictureBuffer(int32 picture_buffer_id) OVERRIDE;
-  virtual void Flush() OVERRIDE;
-  virtual void Reset() OVERRIDE;
-  virtual void Destroy() OVERRIDE;
-
-  // VideoDecodeAcceleratorImpl implementation.
-  virtual bool CanDecodeOnIOThread() OVERRIDE;
-
- private:
-  // These are rather subjectively tuned.
-  enum {
-    kMfcInputBufferCount = 8,
-    // TODO(posciak): determine MFC input buffer size based on level limits.
-    // See http://crbug.com/255116.
-    kMfcInputBufferMaxSize = 1024 * 1024,
-    // Number of output buffers to use for each VDA stage above what's required
-    // by the decoder (e.g. DPB size, in H264).  We need
-    // media::limits::kMaxVideoFrames to fill up the GpuVideoDecode pipeline,
-    // and +1 for a frame in transit.
-    kDpbOutputBufferExtraCount = media::limits::kMaxVideoFrames + 1,
-  };
-
-  // Internal state of the decoder.
-  enum State {
-    kUninitialized,      // Initialize() not yet called.
-    kInitialized,        // Initialize() returned true; ready to start decoding.
-    kDecoding,           // DecodeBufferInitial() successful; decoding frames.
-    kResetting,          // Presently resetting.
-    kAfterReset,         // After Reset(), ready to start decoding again.
-    kChangingResolution, // Performing resolution change, all remaining
-                         // pre-change frames decoded and processed.
-    kError,              // Error in kDecoding state.
-  };
-
-  enum BufferId {
-    kFlushBufferId = -2  // Buffer id for flush buffer, queued by FlushTask().
-  };
-
-  // File descriptors we need to poll.
-  enum PollFds {
-    kPollMfc = (1 << 0),
-  };
-
-  // Auto-destruction reference for BitstreamBuffer, for message-passing from
-  // Decode() to DecodeTask().
-  struct BitstreamBufferRef;
-
-  // Auto-destruction reference for an array of PictureBuffer, for
-  // message-passing from AssignPictureBuffers() to AssignPictureBuffersTask().
-  struct PictureBufferArrayRef;
-
-  // Auto-destruction reference for EGLSync (for message-passing).
-  struct EGLSyncKHRRef;
-
-  // Record for decoded pictures that can be sent to PictureReady.
-  struct PictureRecord;
-
-  // Record for MFC input buffers.
-  struct MfcInputRecord {
-    MfcInputRecord();
-    ~MfcInputRecord();
-    bool at_device;         // held by device.
-    void* address;          // mmap() address.
-    size_t length;          // mmap() length.
-    off_t bytes_used;       // bytes filled in the mmap() segment.
-    int32 input_id;         // triggering input_id as given to Decode().
-  };
-
-  // Record for MFC output buffers.
-  struct MfcOutputRecord {
-    MfcOutputRecord();
-    ~MfcOutputRecord();
-    bool at_device;         // held by device.
-    bool at_client;         // held by client.
-    int fds[2];             // file descriptors for each plane.
-    EGLImageKHR egl_image;  // EGLImageKHR for the output buffer.
-    EGLSyncKHR egl_sync;    // sync the compositor's use of the EGLImage.
-    int32 picture_id;       // picture buffer id as returned to PictureReady().
-    bool cleared;           // Whether the texture is cleared and safe to render
-                            // from. See TextureManager for details.
-  };
-
-  //
-  // Decoding tasks, to be run on decode_thread_.
-  //
-
-  // Enqueue a BitstreamBuffer to decode.  This will enqueue a buffer to the
-  // decoder_input_queue_, then queue a DecodeBufferTask() to actually decode
-  // the buffer.
-  void DecodeTask(const media::BitstreamBuffer& bitstream_buffer);
-
-  // Decode from the buffers queued in decoder_input_queue_.  Calls
-  // DecodeBufferInitial() or DecodeBufferContinue() as appropriate.
-  void DecodeBufferTask();
-  // Advance to the next fragment that begins a frame.
-  bool AdvanceFrameFragment(const uint8* data, size_t size, size_t* endpos);
-  // Schedule another DecodeBufferTask() if we're behind.
-  void ScheduleDecodeBufferTaskIfNeeded();
-
-  // Return true if we should continue to schedule DecodeBufferTask()s after
-  // completion.  Store the amount of input actually consumed in |endpos|.
-  bool DecodeBufferInitial(const void* data, size_t size, size_t* endpos);
-  bool DecodeBufferContinue(const void* data, size_t size);
-
-  // Accumulate data for the next frame to decode.  May return false in
-  // non-error conditions; for example when pipeline is full and should be
-  // retried later.
-  bool AppendToInputFrame(const void* data, size_t size);
-  // Flush data for one decoded frame.
-  bool FlushInputFrame();
-
-  // Process an AssignPictureBuffers() API call.  After this, the
-  // device_poll_thread_ can be started safely, since we have all our
-  // buffers.
-  void AssignPictureBuffersTask(scoped_ptr<PictureBufferArrayRef> pic_buffers);
-
-  // Service I/O on the V4L2 devices.  This task should only be scheduled from
-  // DevicePollTask().  If |mfc_event_pending| is true, one or more events
-  // on MFC file descriptor are pending.
-  void ServiceDeviceTask(bool mfc_event_pending);
-  // Handle the various device queues.
-  void EnqueueMfc();
-  void DequeueMfc();
-  // Handle incoming MFC events.
-  void DequeueMfcEvents();
-  // Enqueue a buffer on the corresponding queue.
-  bool EnqueueMfcInputRecord();
-  bool EnqueueMfcOutputRecord();
-
-  // Process a ReusePictureBuffer() API call.  The API call create an EGLSync
-  // object on the main (GPU process) thread; we will record this object so we
-  // can wait on it before reusing the buffer.
-  void ReusePictureBufferTask(int32 picture_buffer_id,
-                              scoped_ptr<EGLSyncKHRRef> egl_sync_ref);
-
-  // Flush() task.  Child thread should not submit any more buffers until it
-  // receives the NotifyFlushDone callback.  This task will schedule an empty
-  // BitstreamBufferRef (with input_id == kFlushBufferId) to perform the flush.
-  void FlushTask();
-  // Notify the client of a flush completion, if required.  This should be
-  // called any time a relevant queue could potentially be emptied: see
-  // function definition.
-  void NotifyFlushDoneIfNeeded();
-
-  // Reset() task.  This task will schedule a ResetDoneTask() that will send
-  // the NotifyResetDone callback, then set the decoder state to kResetting so
-  // that all intervening tasks will drain.
-  void ResetTask();
-  // ResetDoneTask() will set the decoder state back to kAfterReset, so
-  // subsequent decoding can continue.
-  void ResetDoneTask();
-
-  // Device destruction task.
-  void DestroyTask();
-
-  // Attempt to start/stop device_poll_thread_.
-  bool StartDevicePoll();
-  // If |keep_mfc_input_state| is true, don't reset MFC input state; used during
-  // resolution change.
-  bool StopDevicePoll(bool keep_mfc_input_state);
-  // Set/clear the device poll interrupt (using device_poll_interrupt_fd_).
-  bool SetDevicePollInterrupt();
-  bool ClearDevicePollInterrupt();
-
-  void StartResolutionChangeIfNeeded();
-  void FinishResolutionChange();
-  void ResumeAfterResolutionChange();
-
-  // Try to get output format from MFC, detected after parsing the beginning
-  // of the stream. Sets |again| to true if more parsing is needed.
-  bool GetFormatInfo(struct v4l2_format* format, bool* again);
-  // Create MFC output buffers for the given |format|.
-  bool CreateBuffersForFormat(const struct v4l2_format& format);
-
-  //
-  // 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 decoder_thread_ state (using PostTask to decoder thread, if
-  // necessary).
-  void SetDecoderState(State state);
-
-  //
-  // Other utility functions.  Called on decoder_thread_, unless
-  // decoder_thread_ is not yet started, in which case the child thread can call
-  // these (e.g. in Initialize() or Destroy()).
-  //
-
-  // Create the buffers we need.
-  bool CreateMfcInputBuffers();
-  bool CreateMfcOutputBuffers();
-
-  //
-  // Methods run on child thread.
-  //
-
-  // Destroy buffers.
-  void DestroyMfcInputBuffers();
-  void DestroyMfcOutputBuffers();
-  void ResolutionChangeDestroyBuffers();
-
-  // Send decoded pictures to PictureReady.
-  void SendPictureReady();
-
-  // Callback that indicates a picture has been cleared.
-  void PictureCleared();
-
-  // Our original calling message loop for the child thread.
-  scoped_refptr<base::MessageLoopProxy> child_message_loop_proxy_;
-
-  // Message loop of the IO thread.
-  scoped_refptr<base::MessageLoopProxy> io_message_loop_proxy_;
-
-  // WeakPtr<> pointing to |this| for use in posting tasks from the decoder 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 decoder or device thread should use base::Unretained(this),
-  // and tasks posted the other way should use |weak_this_|.
-  base::WeakPtr<ExynosVideoDecodeAccelerator> weak_this_;
-
-  // To expose client callbacks from VideoDecodeAccelerator.
-  // NOTE: all calls to these objects *MUST* be executed on
-  // child_message_loop_proxy_.
-  base::WeakPtrFactory<Client> client_ptr_factory_;
-  base::WeakPtr<Client> client_;
-  // Callbacks to |io_client_| must be executed on |io_message_loop_proxy_|.
-  base::WeakPtr<Client> io_client_;
-
-  //
-  // Decoder state, owned and operated by decoder_thread_.
-  // Before decoder_thread_ has started, the decoder state is managed by
-  // the child (main) thread.  After decoder_thread_ has started, the decoder
-  // thread should be the only one managing these.
-  //
-
-  // This thread services tasks posted from the VDA API entry points by the
-  // child thread and device service callbacks posted from the device thread.
-  base::Thread decoder_thread_;
-  // Decoder state machine state.
-  State decoder_state_;
-  // BitstreamBuffer we're presently reading.
-  scoped_ptr<BitstreamBufferRef> decoder_current_bitstream_buffer_;
-  // FlushTask() and ResetTask() should not affect buffers that have been
-  // queued afterwards.  For flushing or resetting the pipeline then, we will
-  // delay these buffers until after the flush or reset completes.
-  int decoder_delay_bitstream_buffer_id_;
-  // MFC input buffer we're presently filling.
-  int decoder_current_input_buffer_;
-  // We track the number of buffer decode tasks we have scheduled, since each
-  // task execution should complete one buffer.  If we fall behind (due to
-  // resource backpressure, etc.), we'll have to schedule more to catch up.
-  int decoder_decode_buffer_tasks_scheduled_;
-  // Picture buffers held by the client.
-  int decoder_frames_at_client_;
-  // Are we flushing?
-  bool decoder_flushing_;
-  // Got a notification from driver that it reached resolution change point
-  // in the stream.
-  bool resolution_change_pending_;
-  // Got a reset request while we were performing resolution change.
-  bool resolution_change_reset_pending_;
-  // Input queue for decoder_thread_: BitstreamBuffers in.
-  std::queue<linked_ptr<BitstreamBufferRef> > decoder_input_queue_;
-  // For H264 decode, hardware requires that we send it frame-sized chunks.
-  // We'll need to parse the stream.
-  scoped_ptr<content::H264Parser> decoder_h264_parser_;
-  // Set if the decoder has a pending incomplete frame in an input buffer.
-  bool decoder_partial_frame_pending_;
-
-  //
-  // Hardware state and associated queues.  Since decoder_thread_ services
-  // the hardware, decoder_thread_ owns these too.
-  //
-
-  // Completed decode buffers, waiting for MFC.
-  std::queue<int> mfc_input_ready_queue_;
-
-  // MFC decode device.
-  int mfc_fd_;
-
-  // MFC input buffer state.
-  bool mfc_input_streamon_;
-  // MFC input buffers enqueued to device.
-  int mfc_input_buffer_queued_count_;
-  // Input buffers ready to use, as a 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 buffer state.
-  bool mfc_output_streamon_;
-  // MFC output buffers enqueued to device.
-  int mfc_output_buffer_queued_count_;
-  // Output buffers ready to use, as a FIFO since we want oldest-first to hide
-  // synchronization latency with GL.
-  std::queue<int> mfc_free_output_buffers_;
-  // Mapping of int index to MFC output buffer record.
-  std::vector<MfcOutputRecord> mfc_output_buffer_map_;
-  // MFC output pixel format.
-  uint32 mfc_output_buffer_pixelformat_;
-  // Required size of DPB for decoding.
-  int mfc_output_dpb_size_;
-
-  // Pictures that are ready but not sent to PictureReady yet.
-  std::queue<PictureRecord> pending_picture_ready_;
-
-  // The number of pictures that are sent to PictureReady and will be cleared.
-  int picture_clearing_count_;
-
-  // Output picture size.
-  gfx::Size frame_buffer_size_;
-
-  //
-  // The device polling thread handles notifications of V4L2 device changes.
-  //
-
-  // 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_;
-
-  //
-  // Other state, held by the child (main) thread.
-  //
-
-  // Make our context current before running any EGL entry points.
-  base::Callback<bool(void)> make_context_current_;
-
-  // EGL state
-  EGLDisplay egl_display_;
-
-  // The codec we'll be decoding for.
-  media::VideoCodecProfile video_profile_;
-
-  DISALLOW_COPY_AND_ASSIGN(ExynosVideoDecodeAccelerator);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_COMMON_GPU_MEDIA_EXYNOS_VIDEO_DECODE_ACCELERATOR_H_