arc/codec-test/encoded_data_helper.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_ENCODED_DATA_HELPER_H_
#define ARC_CODEC_TEST_ENCODED_DATA_HELPER_H_

#include <memory>
#include <string>
#include <vector>

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

namespace android {

// Helper class for MediaCodecDecoder to read encoded stream from input file,
// and slice it into fragments. MediaCodecDecoder could call GetNextFragment()
// to obtain fragment data sequentially.
class EncodedDataHelper {
 public:
  EncodedDataHelper(const std::string& file_path, VideoCodecType type);
  ~EncodedDataHelper();

  // A fragment will contain the bytes of one AU (H264) or frame (VP8/9) in
  // |data|, and |csd_flag| indicator for input buffer flag CODEC_CONFIG.
  struct Fragment {
    std::string data;
    bool csd_flag = false;
  };

  // Return the next fragment to be sent to the decoder, and advance the
  // iterator to after the returned fragment.
  const Fragment* const GetNextFragment();

  void Rewind() { next_fragment_iter_ = fragments_.begin(); }
  bool IsValid() const { return !fragments_.empty(); }
  size_t NumValidFragments() const { return fragments_.size(); }
  bool AtHeadOfStream() const;
  bool ReachEndOfStream() const;

 private:
  // NALU type enumeration as defined in H264 Annex-B. Only interested ones are
  // listed here.
  enum NALUType : uint8_t {
    NON_IDR_SLICE = 0x1,
    IDR_SLICE = 0x5,
    SPS = 0x7,
    PPS = 0x8,
  };

  // Slice input stream into fragments. This should be done in constructor.
  void SliceToFragments(const std::string& data);

  // For H264, parse csd_flag from |fragment| data and store inside. Return true
  // if this fragment is in interest; false otherwise (fragment will be
  // discarded.)
  bool ParseAUFragmentType(Fragment* fragment);

  VideoCodecType type_;
  std::vector<std::unique_ptr<Fragment>> fragments_;
  std::vector<std::unique_ptr<Fragment>>::iterator next_fragment_iter_;
};

}  // namespace android

#endif  // ARC_CODEC_TEST_ENCODED_DATA_HELPER_H_