arc/codec-test/mediacodec_decoder.h

// Copyright 2019 The Chromium OS 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 ARC_CODEC_TEST_MEDIACODEC_DECODER_H_
#define ARC_CODEC_TEST_MEDIACODEC_DECODER_H_

#include <memory>
#include <queue>
#include <string>

#include <media/NdkMediaCodec.h>

#include "arc/codec-test/common.h"
#include "arc/codec-test/encoded_data_helper.h"

namespace android {

// Wrapper class to manipulate a MediaCodec video decoder.
class MediaCodecDecoder {
 public:
  // Checks the argument and create MediaCodecDecoder instance.
  static std::unique_ptr<MediaCodecDecoder> Create(
      const std::string& input_path,
      VideoCodecProfile profile,
      const Size& video_size);

  MediaCodecDecoder() = delete;
  ~MediaCodecDecoder();

  // The callback function that is called when output buffer is ready.
  using OutputBufferReadyCb =
      std::function<void(const uint8_t* /* data */, size_t /* buffer_size */)>;
  void SetOutputBufferReadyCb(const OutputBufferReadyCb& cb);

  // The callback function that is called when output format is changed.
  using OutputFormatChangedCb =
      std::function<void(const Size& /* coded_size */,
                         const Size& /* visible_size */,
                         int32_t /* color_format */)>;
  void SetOutputFormatChangedCb(const OutputFormatChangedCb& cb);

  // Decoder manipulation methods.

  // Rewind the input stream to the first frame as well as frame index.
  void Rewind();

  // Wrapper of AMediaCodec_configure.
  bool Configure();

  // Wrapper of AMediaCodec_start.
  bool Start();

  // Decode the input stream. After decoding, send EOS request to the decoder.
  // Return true if EOS output buffer is received.
  bool Decode();

  // Wrapper of AMediaCodec_stop.
  bool Stop();

 private:
  MediaCodecDecoder(AMediaCodec* codec,
                    std::unique_ptr<EncodedDataHelper> encoded_data_helper,
                    VideoCodecType type,
                    const Size& size);

  // Enum class of the status of dequeueing output buffer.
  enum class DequeueStatus { RETRY, SUCCESS, FAILURE };

  // Fill all available input buffers and enqueue.
  bool EnqueueInputBuffers();

  // Try to dequeue one output buffer and return DequeueStatus.
  DequeueStatus DequeueOutputBuffer();

  // Read the sample data from AMediaExtractor or CSD data and feed into the
  // input buffer.
  // |index| is the index of the target input buffer.
  bool FeedInputBuffer(size_t index);

  // Feed an empty buffer with EOS flag.
  // |index| is the index of the target input buffer.
  bool FeedEOSInputBuffer(size_t index);

  // Receive the output buffer and make mOutputBufferReadyCb callback if given.
  // |index| is the index of the target output buffer.
  // |info| is the buffer info of the target output buffer.
  bool ReceiveOutputBuffer(size_t index, const AMediaCodecBufferInfo& info);

  // Get output format by AMediaCodec_getOutputFormat and make
  // |output_format_changed_cb_| callback if given.
  // Return false if required information is missing, e.g. width, color format.
  bool GetOutputFormat();

  // The target mediacodec decoder.
  AMediaCodec* codec_;

  // The reference of EncodedDataHelper.
  std::unique_ptr<EncodedDataHelper> encoded_data_helper_;

  // The codec type of decoding.
  VideoCodecType type_;
  // The output video visible size.
  Size input_visible_size_;

  // The callback function which is called when a output buffer is ready.
  OutputBufferReadyCb output_buffer_ready_cb_;
  // The callback function that is called when output format is changed.
  OutputFormatChangedCb output_format_changed_cb_;

  // The fragment index that indicates which frame is sent to the decoder at
  // next round.
  int input_fragment_index_ = 0;
  // The total number of received output buffers. Only used for logging.
  int received_outputs_ = 0;

  // The indication of input done.
  bool input_done_ = false;
  // The indication of output done.
  bool output_done_ = false;
};

}  // namespace android

#endif  // ARC_CODEC_TEST_MEDIACODEC_DECODER_H_