Add accelerated video decoder interface, VP8 and H.264 implementations and hook up to V4L2SVDA.

content/common/gpu/media/v4l2_slice_video_decode_accelerator.h

+// Copyright 2015 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_V4L2_SLICE_VIDEO_DECODE_ACCELERATOR_H_
+#define CONTENT_COMMON_GPU_MEDIA_V4L2_SLICE_VIDEO_DECODE_ACCELERATOR_H_
+
+#include <linux/videodev2.h>
+#include <queue>
+#include <vector>
+
+#include "base/memory/linked_ptr.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/threading/thread.h"
+#include "content/common/content_export.h"
+#include "content/common/gpu/media/h264_decoder.h"
+#include "content/common/gpu/media/v4l2_video_device.h"
+#include "content/common/gpu/media/vp8_decoder.h"
+#include "media/video/video_decode_accelerator.h"
+
+namespace content {
+
+// An implementation of VideoDecodeAccelerator that utilizes the V4L2 slice
+// level codec API for decoding. The slice level API provides only a low-level
+// decoding functionality and requires userspace to provide support for parsing
+// the input stream and managing decoder state across frames.
+class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
+    : public media::VideoDecodeAccelerator {
+ public:
+  class V4L2DecodeSurface;
+
+  V4L2SliceVideoDecodeAccelerator(
+      const scoped_refptr<V4L2Device>& device,
+      EGLDisplay egl_display,
+      EGLContext egl_context,
+      const base::WeakPtr<Client>& io_client_,
+      const base::Callback<bool(void)>& make_context_current,
+      const scoped_refptr<base::MessageLoopProxy>& io_message_loop_proxy);
+  virtual ~V4L2SliceVideoDecodeAccelerator() override;
+
+  // media::VideoDecodeAccelerator implementation.
+  bool Initialize(media::VideoCodecProfile profile,
+                  VideoDecodeAccelerator::Client* client) override;
+  void Decode(const media::BitstreamBuffer& bitstream_buffer) override;
+  void AssignPictureBuffers(
+      const std::vector<media::PictureBuffer>& buffers) override;
+  void ReusePictureBuffer(int32 picture_buffer_id) override;
+  void Flush() override;
+  void Reset() override;
+  void Destroy() override;
+  bool CanDecodeOnIOThread() override;
+
+ private:
+  class V4L2H264Accelerator;
+  class V4L2VP8Accelerator;
+
+  // Record for input buffers.
+  struct InputRecord {
+    InputRecord();
+    int32 input_id;
+    void* address;
+    size_t length;
+    size_t bytes_used;
+    bool at_device;
+  };
+
+  // Record for output buffers.
+  struct OutputRecord {
+    OutputRecord();
+    bool at_device;
+    bool at_client;
+    int32 picture_id;
+    EGLImageKHR egl_image;
+    EGLSyncKHR egl_sync;
+    bool cleared;
+  };
+
+  // See http://crbug.com/255116.
+  // Input bitstream buffer size for up to 1080p streams.
+  const size_t kInputBufferMaxSizeFor1080p = 1024 * 1024;
+  // Input bitstream buffer size for up to 4k streams.
+  const size_t kInputBufferMaxSizeFor4k = 4 * kInputBufferMaxSizeFor1080p;
+  const size_t kNumInputBuffers = 16;
+
+  //
+  // Below methods are used by accelerator implementations.
+  //
+  // Append slice data in |data| of size |size| to pending hardware
+  // input buffer with |index|. This buffer will be submitted for decode
+  // on the next DecodeSurface(). Return true on success.
+  bool SubmitSlice(int index, const uint8_t* data, size_t size);
+
+  // Submit controls in |ext_ctrls| to hardware. Return true on success.
+  bool SubmitExtControls(struct v4l2_ext_controls* ext_ctrls);
+
+  // Decode of |dec_surface| is ready to be submitted and all codec-specific
+  // settings are set in hardware.
+  void DecodeSurface(const scoped_refptr<V4L2DecodeSurface>& dec_surface);
+
+  // |dec_surface| is ready to be outputted once decode is finished.
+  // This can be called before decode is actually done in hardware, and this
+  // method is responsible for maintaining the ordering, i.e. the surfaces will
+  // be outputted in the same order as SurfaceReady calls. To do so, the
+  // surfaces are put on decoder_display_queue_ and sent to output in that
+  // order once all preceding surfaces are sent.
+  void SurfaceReady(const scoped_refptr<V4L2DecodeSurface>& dec_surface);
+
+  //
+  // Internal methods of this class.
+  //
+  // Recycle V4L2 output buffer with |index|. Used as surface release callback.
+  void ReuseOutputBuffer(int index);
+
+  // Queue a |dec_surface| to device for decoding.
+  void Enqueue(const scoped_refptr<V4L2DecodeSurface>& dec_surface);
+
+  // Dequeue any V4L2 buffers available and process.
+  void Dequeue();
+
+  // V4L2 QBUF helpers.
+  bool EnqueueInputRecord(int index, uint32_t config_store);
+  bool EnqueueOutputRecord(int index);
+
+  // Set input and output formats in hardware.
+  bool SetupFormats();
+
+  // Create input and output buffers.
+  bool CreateInputBuffers();
+  bool CreateOutputBuffers();
+
+  // Destroy input buffers.
+  void DestroyInputBuffers();
+
+  // Destroy output buffers and release associated resources (textures,
+  // EGLImages). If |dismiss| is true, also dismissing the associated
+  // PictureBuffers.
+  bool DestroyOutputs(bool dismiss);
+
+  // Used by DestroyOutputs.
+  bool DestroyOutputBuffers();
+
+  // Dismiss all |picture_buffer_ids| via Client::DismissPictureBuffer()
+  // and signal |done| after finishing.
+  void DismissPictures(std::vector<int32> picture_buffer_ids,
+                       base::WaitableEvent* done);
+
+  // Task to finish initialization on decoder_thread_.
+  void InitializeTask();
+
+  // Surface set change (resolution change) flow.
+  // If we have no surfaces allocated, just allocate them and return.
+  // Otherwise mark us as pending for surface set change.
+  void InitiateSurfaceSetChange();
+  // If a surface set change is pending and we are ready, stop the device,
+  // destroy outputs, releasing resources and dismissing pictures as required,
+  // followed by allocating a new set for the new resolution/DPB size
+  // as provided by decoder. Finally, try to resume decoding.
+  void FinishSurfaceSetChangeIfNeeded();
+
+  void NotifyError(Error error);
+  void DestroyTask();
+
+  // Sets the state to kError and notifies client if needed.
+  void SetErrorState(Error error);
+
+  // Flush flow when requested by client.
+  // When Flush() is called, it posts a FlushTask, which checks the input queue.
+  // If nothing is pending for decode on decoder_input_queue_, we call
+  // InitiateFlush() directly. Otherwise, we push a dummy BitstreamBufferRef
+  // onto the decoder_input_queue_ to schedule a flush. When we reach it later
+  // on, we call InitiateFlush() to perform it at the correct time.
+  void FlushTask();
+  // Tell the decoder to flush all frames, reset it and mark us as scheduled
+  // for flush, so that we can finish it once all pending decodes are finished.
+  void InitiateFlush();
+  // If all pending frames are decoded and we are waiting to flush, perform it.
+  // This will send all pending pictures to client and notify the client that
+  // flush is complete and puts us in a state ready to resume.
+  void FinishFlushIfNeeded();
+
+  // Reset flow when requested by client.
+  // Drop all inputs and reset the decoder and mark us as pending for reset.
+  void ResetTask();
+  // If all pending frames are decoded and we are waiting to reset, perform it.
+  // This drops all pending outputs (client is not interested anymore),
+  // notifies the client we are done and puts us in a state ready to resume.
+  void FinishResetIfNeeded();
+
+  // Process pending events if any.
+  void ProcessPendingEventsIfNeeded();
+
+  // Performed on decoder_thread_ as a consequence of poll() on decoder_thread_
+  // returning an event.
+  void ServiceDeviceTask();
+
+  // Schedule poll if we have any buffers queued and the poll thread
+  // is not stopped (on surface set change).
+  void SchedulePollIfNeeded();
+
+  // Attempt to start/stop device_poll_thread_.
+  bool StartDevicePoll();
+  bool StopDevicePoll(bool keep_input_state);
+
+  // Ran on device_poll_thread_ to wait for device events.
+  void DevicePollTask(bool poll_device);
+
+  enum State {
+    // We are in this state until Initialize() returns successfully.
+    // We can't post errors to the client in this state yet.
+    kUninitialized,
+    // Initialize() returned successfully.
+    kInitialized,
+    // This state allows making progress decoding more input stream.
+    kDecoding,
+    // Transitional state when we are not decoding any more stream, but are
+    // performing flush, reset, resolution change or are destroying ourselves.
+    kIdle,
+    // Error state, set when sending NotifyError to client.
+    kError,
+  };
+
+  // Buffer id for flush buffer, queued by FlushTask().
+  const int kFlushBufferId = -2;
+
+  // Handler for Decode() on decoder_thread_.
+  void DecodeTask(const media::BitstreamBuffer& bitstream_buffer);
+
+  // Schedule a new DecodeBufferTask if we are decoding.
+  void ScheduleDecodeBufferTaskIfNeeded();
+
+  // Main decoder loop. Keep decoding the current buffer in decoder_, asking
+  // for more stream via TrySetNewBistreamBuffer() if decoder_ requests so,
+  // and handle other returns from it appropriately.
+  void DecodeBufferTask();
+
+  // Check decoder_input_queue_ for any available buffers to decode and
+  // set the decoder_current_bitstream_buffer_ to the next buffer if one is
+  // available, taking it off the queue. Also set the current stream pointer
+  // in decoder_, and return true.
+  // Return false if no buffers are pending on decoder_input_queue_.
+  bool TrySetNewBistreamBuffer();
+
+  // Auto-destruction reference for EGLSync (for message-passing).
+  struct EGLSyncKHRRef;
+  void ReusePictureBufferTask(int32 picture_buffer_id,
+                              scoped_ptr<EGLSyncKHRRef> egl_sync_ref);
+
+  // Called to actually send |dec_surface| to the client, after it is decoded
+  // preserving the order in which it was scheduled via SurfaceReady().
+  void OutputSurface(const scoped_refptr<V4L2DecodeSurface>& dec_surface);
+
+  // Goes over the |decoder_display_queue_| and sends all buffers from the
+  // front of the queue that are already decoded to the client, in order.
+  void TryOutputSurfaces();
+
+  // Creates a new decode surface or returns nullptr if one is not available.
+  scoped_refptr<V4L2DecodeSurface> CreateSurface();
+
+  // Send decoded pictures to PictureReady.
+  void SendPictureReady();
+
+  // Callback that indicates a picture has been cleared.
+  void PictureCleared();
+
+  size_t input_planes_count_;
+  size_t output_planes_count_;
+
+  // GPU Child thread message loop.
+  const scoped_refptr<base::MessageLoopProxy> child_message_loop_proxy_;
+
+  // IO thread message loop.
+  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.
+  base::WeakPtr<V4L2SliceVideoDecodeAccelerator> weak_this_;
+
+  // To expose client callbacks from VideoDecodeAccelerator.
+  // NOTE: all calls to these objects *MUST* be executed on
+  // child_message_loop_proxy_.
+  scoped_ptr<base::WeakPtrFactory<VideoDecodeAccelerator::Client>>
+      client_ptr_factory_;
+  base::WeakPtr<VideoDecodeAccelerator::Client> client_;
+  // Callbacks to |io_client_| must be executed on |io_message_loop_proxy_|.
+  base::WeakPtr<Client> io_client_;
+
+  // V4L2 device in use.
+  scoped_refptr<V4L2Device> device_;
+
+  // Thread to communicate with the device on.
+  base::Thread decoder_thread_;
+  scoped_refptr<base::MessageLoopProxy> decoder_thread_proxy_;
+
+  // Thread used to poll the device for events.
+  base::Thread device_poll_thread_;
+
+  // Input queue state.
+  bool input_streamon_;
+  // Number of input buffers enqueued to the device.
+  int input_buffer_queued_count_;
+  // Input buffers ready to use; LIFO since we don't care about ordering.
+  std::list<int> free_input_buffers_;
+  // Mapping of int index to an input buffer record.
+  std::vector<InputRecord> input_buffer_map_;
+
+  // Output queue state.
+  bool output_streamon_;
+  // Number of output buffers enqueued to the device.
+  int output_buffer_queued_count_;
+  // Output buffers ready to use.
+  std::list<int> free_output_buffers_;
+  // Mapping of int index to an output buffer record.
+  std::vector<OutputRecord> output_buffer_map_;
+
+  media::VideoCodecProfile video_profile_;
+  uint32_t output_format_fourcc_;
+  gfx::Size frame_buffer_size_;
+  size_t output_dpb_size_;
+
+  struct BitstreamBufferRef;
+  // Input queue of stream buffers coming from the client.
+  std::queue<linked_ptr<BitstreamBufferRef>> decoder_input_queue_;
+  // BitstreamBuffer currently being processed.
+  scoped_ptr<BitstreamBufferRef> decoder_current_bitstream_buffer_;
+
+  // Queue storing decode surfaces ready to be output as soon as they are
+  // decoded. The surfaces must be output in order they are queued.
+  std::queue<scoped_refptr<V4L2DecodeSurface>> decoder_display_queue_;
+
+  // Decoder state.
+  State state_;
+
+  // If any of these are true, we are waiting for the device to finish decoding
+  // all previously-queued frames, so we can finish the flush/reset/surface
+  // change flows. These can stack.
+  bool decoder_flushing_;
+  bool decoder_resetting_;
+  bool surface_set_change_pending_;
+
+  // Hardware accelerators.
+  // TODO(posciak): Try to have a superclass here if possible.
+  scoped_ptr<V4L2H264Accelerator> h264_accelerator_;
+  scoped_ptr<V4L2VP8Accelerator> vp8_accelerator_;
+
+  // Codec-specific software decoder in use.
+  scoped_ptr<AcceleratedVideoDecoder> decoder_;
+
+  // Surfaces queued to device to keep references to them while decoded.
+  using V4L2DecodeSurfaceByOutputId =
+      std::map<int, scoped_refptr<V4L2DecodeSurface>>;
+  V4L2DecodeSurfaceByOutputId surfaces_at_device_;
+
+  // Surfaces sent to client to keep references to them while displayed.
+  using V4L2DecodeSurfaceByPictureBufferId =
+      std::map<int32, scoped_refptr<V4L2DecodeSurface>>;
+  V4L2DecodeSurfaceByPictureBufferId surfaces_at_display_;
+
+  // Record for decoded pictures that can be sent to PictureReady.
+  struct PictureRecord;
+  // 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_;
+
+  // Used by the decoder thread to wait for AssignPictureBuffers to arrive
+  // to avoid races with potential Reset requests.
+  base::WaitableEvent pictures_assigned_;
+
+  // Make the GL context current callback.
+  base::Callback<bool(void)> make_context_current_;
+
+  // EGL state
+  EGLDisplay egl_display_;
+  EGLContext egl_context_;
+
+  // The WeakPtrFactory for |weak_this_|.
+  base::WeakPtrFactory<V4L2SliceVideoDecodeAccelerator> weak_this_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(V4L2SliceVideoDecodeAccelerator);
+};
+
+class V4L2H264Picture;
+class V4L2VP8Picture;
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_V4L2_SLICE_VIDEO_DECODE_ACCELERATOR_H_