packed_audio_segmenter.h

// Copyright 2018 Google LLC. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
 
#ifndef PACKAGER_MEDIA_FORMATS_PACKED_AUDIO_PACKED_AUDIO_SEGMENTER_H_
#define PACKAGER_MEDIA_FORMATS_PACKED_AUDIO_PACKED_AUDIO_SEGMENTER_H_
 
#include <memory>
 
#include "packager/media/base/buffer_writer.h"
#include "packager/media/base/stream_info.h"
#include "packager/status.h"
 
namespace shaka {
namespace media {
 
class AACAudioSpecificConfig;
class Id3Tag;
class MediaSample;
 
constexpr double kPackedAudioTimescale = 90000;
 
constexpr char kTimestampOwnerIdentifier[] =
    "com.apple.streaming.transportStreamTimestamp";
 
constexpr char kAudioDescriptionOwnerIdentifier[] =
    "com.apple.streaming.audioDescription";
 
class PackedAudioSegmenter {
 public:
  explicit PackedAudioSegmenter(uint32_t transport_stream_timestamp_offset);
  virtual ~PackedAudioSegmenter();
 
  // This function is made virtual for testing.
  virtual Status Initialize(const StreamInfo& stream_info);
 
  // This function is made virtual for testing.
  virtual Status AddSample(const MediaSample& sample);
 
  // This function is made virtual for testing.
  virtual Status FinalizeSegment();
 
  // This function is made virtual for testing.
  virtual double TimescaleScale() const;
 
  BufferWriter* segment_buffer() { return &segment_buffer_; }
 
 private:
  PackedAudioSegmenter(const PackedAudioSegmenter&) = delete;
  PackedAudioSegmenter& operator=(const PackedAudioSegmenter&) = delete;
 
  // These functions is made virtual for testing.
  virtual std::unique_ptr<AACAudioSpecificConfig> CreateAdtsConverter();
  virtual std::unique_ptr<Id3Tag> CreateId3Tag();
 
  Status EncryptionAudioSetup(const MediaSample& sample);
  Status StartNewSegment(const MediaSample& first_sample);
 
  const uint32_t transport_stream_timestamp_offset_ = 0;
  // Codec for the stream.
  Codec codec_ = kUnknownCodec;
  std::vector<uint8_t> audio_codec_config_;
  // Calculated by output stream's timescale / input stream's timescale. This is
  // used to scale the timestamps.
  double timescale_scale_ = 0.0;
  // Whether it is the start of a new segment.
  bool start_of_new_segment_ = true;
 
  // Audio setup information for encrypted segment.
  std::string audio_setup_information_;
  // AAC is carried in ADTS.
  std::unique_ptr<AACAudioSpecificConfig> adts_converter_;
 
  BufferWriter segment_buffer_;
};
 
}  // namespace media
}  // namespace shaka
 
#endif  // PACKAGER_MEDIA_FORMATS_PACKED_AUDIO_PACKED_AUDIO_SEGMENTER_H_