box_definitions.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.
 
#ifndef PACKAGER_MEDIA_FORMATS_MP4_BOX_DEFINITIONS_H_
#define PACKAGER_MEDIA_FORMATS_MP4_BOX_DEFINITIONS_H_
 
#include <vector>
 
#include "packager/media/base/decrypt_config.h"
#include "packager/media/base/fourccs.h"
#include "packager/media/codecs/aac_audio_specific_config.h"
#include "packager/media/codecs/es_descriptor.h"
#include "packager/media/formats/mp4/box.h"
 
namespace shaka {
namespace media {
 
class BufferReader;
 
namespace mp4 {
 
enum TrackType {
  kInvalid = 0,
  kVideo,
  kAudio,
  kHint,
  kText,
  kSubtitle,
};
 
class BoxBuffer;
 
#define DECLARE_BOX_METHODS(T)                        \
 public:                                              \
  T();                                                \
  ~T() override;                                      \
                                                      \
  FourCC BoxType() const override;                    \
                                                      \
 private:                                             \
  bool ReadWriteInternal(BoxBuffer* buffer) override; \
  size_t ComputeSizeInternal() override;              \
                                                      \
 public:
 
struct FileType : Box {
  DECLARE_BOX_METHODS(FileType);
 
  FourCC major_brand = FOURCC_NULL;
  uint32_t minor_version = 0;
  std::vector<FourCC> compatible_brands;
};
 
struct SegmentType : FileType {
  FourCC BoxType() const override;
};
 
struct ProtectionSystemSpecificHeader : FullBox {
  DECLARE_BOX_METHODS(ProtectionSystemSpecificHeader);
 
  std::vector<uint8_t> raw_box;
};
 
struct SampleAuxiliaryInformationOffset : FullBox {
  DECLARE_BOX_METHODS(SampleAuxiliaryInformationOffset);
 
  std::vector<uint64_t> offsets;
};
 
struct SampleAuxiliaryInformationSize : FullBox {
  DECLARE_BOX_METHODS(SampleAuxiliaryInformationSize);
 
  uint8_t default_sample_info_size = 0;
  uint32_t sample_count = 0;
  std::vector<uint8_t> sample_info_sizes;
};
 
struct SampleEncryptionEntry {
  bool ReadWrite(uint8_t iv_size, bool has_subsamples, BoxBuffer* buffer);
  bool ParseFromBuffer(uint8_t iv_size,
                       bool has_subsamples,
                       BufferReader* reader);
  uint32_t ComputeSize() const;
  uint32_t GetTotalSizeOfSubsamples() const;
 
  std::vector<uint8_t> initialization_vector;
  std::vector<SubsampleEntry> subsamples;
};
 
struct SampleEncryption : FullBox {
  static const uint8_t kInvalidIvSize = 1;
 
  enum SampleEncryptionFlags {
    kUseSubsampleEncryption = 2,
  };
 
  DECLARE_BOX_METHODS(SampleEncryption);
  bool ParseFromSampleEncryptionData(
      uint8_t iv_size,
      std::vector<SampleEncryptionEntry>* sample_encryption_entries) const;
 
  std::vector<uint8_t> sample_encryption_data;
 
  uint8_t iv_size = kInvalidIvSize;
  std::vector<SampleEncryptionEntry> sample_encryption_entries;
};
 
struct OriginalFormat : Box {
  DECLARE_BOX_METHODS(OriginalFormat);
 
  FourCC format = FOURCC_NULL;
};
 
struct SchemeType : FullBox {
  DECLARE_BOX_METHODS(SchemeType);
 
  FourCC type = FOURCC_NULL;
  uint32_t version = 0u;
};
 
struct TrackEncryption : FullBox {
  DECLARE_BOX_METHODS(TrackEncryption);
 
  uint8_t default_is_protected = 0;
  uint8_t default_per_sample_iv_size = 0;
  // Default to a vector of 16 zeros.
  std::vector<uint8_t> default_kid = std::vector<uint8_t>(16, 0);
 
  // For pattern-based encryption.
  uint8_t default_crypt_byte_block = 0;
  uint8_t default_skip_byte_block = 0;
 
  // Present only if
  // |default_is_protected == 1 && default_per_sample_iv_size == 0|.
  std::vector<uint8_t> default_constant_iv;
};
 
struct SchemeInfo : Box {
  DECLARE_BOX_METHODS(SchemeInfo);
 
  TrackEncryption track_encryption;
};
 
struct ProtectionSchemeInfo : Box {
  DECLARE_BOX_METHODS(ProtectionSchemeInfo);
 
  OriginalFormat format;
  SchemeType type;
  SchemeInfo info;
};
 
struct MovieHeader : FullBox {
  DECLARE_BOX_METHODS(MovieHeader);
 
  uint64_t creation_time = 0;
  uint64_t modification_time = 0;
  uint32_t timescale = 0;
  uint64_t duration = 0;
  int32_t rate = 1 << 16;
  int16_t volume = 1 << 8;
  uint32_t next_track_id = 0;
};
 
struct TrackHeader : FullBox {
  enum TrackHeaderFlags {
    kTrackEnabled = 0x000001,
    kTrackInMovie = 0x000002,
    kTrackInPreview = 0x000004,
  };
 
  DECLARE_BOX_METHODS(TrackHeader);
 
  uint64_t creation_time = 0;
  uint64_t modification_time = 0;
  uint32_t track_id = 0;
  uint64_t duration = 0;
  int16_t layer = 0;
  int16_t alternate_group = 0;
  int16_t volume = -1;
  // width and height specify the track's visual presentation size as
  // fixed-point 16.16 values.
  uint32_t width = 0;
  uint32_t height = 0;
};
 
struct EditListEntry {
  uint64_t segment_duration = 0;
  int64_t media_time = 0;
  int16_t media_rate_integer = 0;
  int16_t media_rate_fraction = 0;
};
 
struct EditList : FullBox {
  DECLARE_BOX_METHODS(EditList);
 
  std::vector<EditListEntry> edits;
};
 
struct Edit : Box {
  DECLARE_BOX_METHODS(Edit);
 
  EditList list;
};
 
struct HandlerReference : FullBox {
  DECLARE_BOX_METHODS(HandlerReference);
 
  FourCC handler_type = FOURCC_NULL;
};
 
struct Language {
  bool ReadWrite(BoxBuffer* buffer);
  uint32_t ComputeSize() const;
 
  std::string code;
};
 
struct ID3v2 : FullBox {
  DECLARE_BOX_METHODS(ID3v2);
 
  Language language;
  std::vector<uint8_t> id3v2_data;
};
 
struct Metadata : FullBox {
  DECLARE_BOX_METHODS(Metadata);
 
  HandlerReference handler;
  ID3v2 id3v2;
};
 
// This defines a common structure for various CodecConfiguration boxes:
// AVCConfiguration, HEVCConfiguration and VPCodecConfiguration.
// Note that unlike the other two CodecConfiguration boxes, VPCodecConfiguration
// box inherits from FullBox instead of Box, according to VP Codec ISO Media
// File Format Binding specification. It will be handled properly in the
// implementation.
struct CodecConfiguration : Box {
  DECLARE_BOX_METHODS(CodecConfiguration);
 
  FourCC box_type = FOURCC_NULL;
  // Contains full codec configuration record, including possible extension
  // boxes.
  std::vector<uint8_t> data;
};
 
struct PixelAspectRatio : Box {
  DECLARE_BOX_METHODS(PixelAspectRatio);
 
  uint32_t h_spacing = 0u;
  uint32_t v_spacing = 0u;
};
 
struct VideoSampleEntry : Box {
  DECLARE_BOX_METHODS(VideoSampleEntry);
 
  // Returns actual format of this sample entry.
  FourCC GetActualFormat() const {
    return format == FOURCC_encv ? sinf.format.format : format;
  }
  // Returns the box type of codec configuration box from video format.
  FourCC GetCodecConfigurationBoxType(FourCC format) const;
 
  // Convert |extra_codec_configs| to vector.
  std::vector<uint8_t> ExtraCodecConfigsAsVector() const;
  // Parse |extra_codec_configs| from vector.
  bool ParseExtraCodecConfigsVector(const std::vector<uint8_t>& data);
 
  FourCC format = FOURCC_NULL;
  // data_reference_index is 1-based and "dref" box is mandatory so it is
  // always present.
  uint16_t data_reference_index = 1u;
  uint16_t width = 0u;
  uint16_t height = 0u;
 
  PixelAspectRatio pixel_aspect;
  ProtectionSchemeInfo sinf;
  CodecConfiguration codec_configuration;
  // Some codecs, e.g. Dolby Vision, have extra codec configuration boxes that
  // need to be propagated to muxers.
  std::vector<CodecConfiguration> extra_codec_configs;
};
 
struct ElementaryStreamDescriptor : FullBox {
  DECLARE_BOX_METHODS(ElementaryStreamDescriptor);
 
  AACAudioSpecificConfig aac_audio_specific_config;
  ESDescriptor es_descriptor;
};
 
struct DTSSpecific : Box {
  DECLARE_BOX_METHODS(DTSSpecific);
 
  uint32_t sampling_frequency = 0u;
  uint32_t max_bitrate = 0u;
  uint32_t avg_bitrate = 0u;
  uint8_t pcm_sample_depth = 0u;
  std::vector<uint8_t> extra_data;
};
 
struct AC3Specific : Box {
  DECLARE_BOX_METHODS(AC3Specific);
 
  std::vector<uint8_t> data;
};
 
struct EC3Specific : Box {
  DECLARE_BOX_METHODS(EC3Specific);
 
  std::vector<uint8_t> data;
};
 
struct AC4Specific : Box {
  DECLARE_BOX_METHODS(AC4Specific);
 
  std::vector<uint8_t> data;
};
 
struct OpusSpecific : Box {
  DECLARE_BOX_METHODS(OpusSpecific);
 
  std::vector<uint8_t> opus_identification_header;
  // The number of priming samples. Extracted from |opus_identification_header|.
  uint16_t preskip = 0u;
};
 
// FLAC specific decoder configuration box:
//   https://github.com/xiph/flac/blob/master/doc/isoflac.txt
// We do not care about the actual data inside, which is simply copied over.
struct FlacSpecific : FullBox {
  DECLARE_BOX_METHODS(FlacSpecific);
 
  std::vector<uint8_t> data;
};
 
struct AudioSampleEntry : Box {
  DECLARE_BOX_METHODS(AudioSampleEntry);
 
  // Returns actual format of this sample entry.
  FourCC GetActualFormat() const {
    return format == FOURCC_enca ? sinf.format.format : format;
  }
 
  FourCC format = FOURCC_NULL;
  // data_reference_index is 1-based and "dref" box is mandatory so it is
  // always present.
  uint16_t data_reference_index = 1u;
  uint16_t channelcount = 2u;
  uint16_t samplesize = 16u;
  uint32_t samplerate = 0u;
 
  ProtectionSchemeInfo sinf;
 
  ElementaryStreamDescriptor esds;
  DTSSpecific ddts;
  AC3Specific dac3;
  EC3Specific dec3;
  AC4Specific dac4;
  OpusSpecific dops;
  FlacSpecific dfla;
};
 
struct WebVTTConfigurationBox : Box {
  DECLARE_BOX_METHODS(WebVTTConfigurationBox);
 
  std::string config;
};
 
struct WebVTTSourceLabelBox : Box {
  DECLARE_BOX_METHODS(WebVTTSourceLabelBox);
 
  std::string source_label;
};
 
struct TextSampleEntry : Box {
  DECLARE_BOX_METHODS(TextSampleEntry);
 
  // Specifies fourcc of this sample entry. It needs to be set on write, e.g.
  // set to 'wvtt' to write WVTTSampleEntry; On read, it is recovered from box
  // header.
  FourCC format = FOURCC_NULL;
 
  // data_reference_index is 1-based and "dref" box is mandatory so it is
  // always present.
  uint16_t data_reference_index = 1u;
 
  // Sub fields for ttml text sample entry.
  std::string namespace_;
  std::string schema_location;
  // Optional MPEG4BitRateBox.
 
  // Sub boxes for wvtt text sample entry.
  WebVTTConfigurationBox config;
  WebVTTSourceLabelBox label;
  // Optional MPEG4BitRateBox.
};
 
struct SampleDescription : FullBox {
  DECLARE_BOX_METHODS(SampleDescription);
 
  TrackType type = kInvalid;
  // TODO(kqyang): Clean up the code to have one single member, e.g. by creating
  // SampleEntry struct, std::vector<SampleEntry> sample_entries.
  std::vector<VideoSampleEntry> video_entries;
  std::vector<AudioSampleEntry> audio_entries;
  std::vector<TextSampleEntry> text_entries;
};
 
struct DecodingTime {
  uint32_t sample_count;
  uint32_t sample_delta;
};
 
// stts.
struct DecodingTimeToSample : FullBox {
  DECLARE_BOX_METHODS(DecodingTimeToSample);
 
  std::vector<DecodingTime> decoding_time;
};
 
struct CompositionOffset {
  uint32_t sample_count;
  // If version == 0, sample_offset is uint32_t;
  // If version == 1, sample_offset is int32_t.
  // Use int64_t so both can be supported properly.
  int64_t sample_offset;
};
 
// ctts. Optional.
struct CompositionTimeToSample : FullBox {
  DECLARE_BOX_METHODS(CompositionTimeToSample);
 
  std::vector<CompositionOffset> composition_offset;
};
 
struct ChunkInfo {
  uint32_t first_chunk;
  uint32_t samples_per_chunk;
  uint32_t sample_description_index;
};
 
// stsc.
struct SampleToChunk : FullBox {
  DECLARE_BOX_METHODS(SampleToChunk);
 
  std::vector<ChunkInfo> chunk_info;
};
 
// stsz.
struct SampleSize : FullBox {
  DECLARE_BOX_METHODS(SampleSize);
 
  uint32_t sample_size = 0u;
  uint32_t sample_count = 0u;
  std::vector<uint32_t> sizes;
};
 
// stz2.
struct CompactSampleSize : FullBox {
  DECLARE_BOX_METHODS(CompactSampleSize);
 
  uint8_t field_size = 0u;
  std::vector<uint32_t> sizes;
};
 
// co64.
struct ChunkLargeOffset : FullBox {
  DECLARE_BOX_METHODS(ChunkLargeOffset);
 
  std::vector<uint64_t> offsets;
};
 
// stco.
struct ChunkOffset : ChunkLargeOffset {
  DECLARE_BOX_METHODS(ChunkOffset);
};
 
// stss. Optional.
struct SyncSample : FullBox {
  DECLARE_BOX_METHODS(SyncSample);
 
  std::vector<uint32_t> sample_number;
};
 
struct CencSampleEncryptionInfoEntry {
  bool ReadWrite(BoxBuffer* buffer);
  uint32_t ComputeSize() const;
 
  uint8_t is_protected = 0u;
  uint8_t per_sample_iv_size = 0u;
  std::vector<uint8_t> key_id;
 
  // For pattern-based encryption.
  uint8_t crypt_byte_block = 0u;
  uint8_t skip_byte_block = 0u;
 
  // Present only if |is_protected == 1 && per_sample_iv_size == 0|.
  std::vector<uint8_t> constant_iv;
};
 
struct AudioRollRecoveryEntry {
  bool ReadWrite(BoxBuffer* buffer);
  uint32_t ComputeSize() const;
 
  int16_t roll_distance = 0;
};
 
struct SampleGroupDescription : FullBox {
  DECLARE_BOX_METHODS(SampleGroupDescription);
 
  template <typename T>
  bool ReadWriteEntries(BoxBuffer* buffer, std::vector<T>* entries);
 
  uint32_t grouping_type = 0;
  // Only present if grouping_type == 'seig'.
  std::vector<CencSampleEncryptionInfoEntry>
      cenc_sample_encryption_info_entries;
  // Only present if grouping_type == 'roll'.
  std::vector<AudioRollRecoveryEntry> audio_roll_recovery_entries;
};
 
struct SampleToGroupEntry {
  enum GroupDescriptionIndexBase {
    kTrackGroupDescriptionIndexBase = 0,
    kTrackFragmentGroupDescriptionIndexBase = 0x10000,
  };
 
  uint32_t sample_count = 0u;
  uint32_t group_description_index = 0u;
};
 
struct SampleToGroup : FullBox {
  DECLARE_BOX_METHODS(SampleToGroup);
 
  uint32_t grouping_type = 0u;
  uint32_t grouping_type_parameter = 0u;  // Version 1 only.
  std::vector<SampleToGroupEntry> entries;
};
 
struct SampleTable : Box {
  DECLARE_BOX_METHODS(SampleTable);
 
  SampleDescription description;
  DecodingTimeToSample decoding_time_to_sample;
  CompositionTimeToSample composition_time_to_sample;
  SampleToChunk sample_to_chunk;
  // Either SampleSize or CompactSampleSize must present. Store in SampleSize.
  SampleSize sample_size;
  // Either ChunkOffset or ChunkLargeOffset must present. Store in
  // ChunkLargeOffset.
  ChunkLargeOffset chunk_large_offset;
  SyncSample sync_sample;
  std::vector<SampleGroupDescription> sample_group_descriptions;
  std::vector<SampleToGroup> sample_to_groups;
};
 
struct MediaHeader : FullBox {
  DECLARE_BOX_METHODS(MediaHeader);
 
  uint64_t creation_time = 0u;
  uint64_t modification_time = 0u;
  uint32_t timescale = 0u;
  uint64_t duration = 0u;
  Language language;
};
 
struct VideoMediaHeader : FullBox {
  DECLARE_BOX_METHODS(VideoMediaHeader);
 
  uint16_t graphicsmode = 0u;
  uint16_t opcolor_red = 0u;
  uint16_t opcolor_green = 0u;
  uint16_t opcolor_blue = 0u;
};
 
struct SoundMediaHeader : FullBox {
  DECLARE_BOX_METHODS(SoundMediaHeader);
 
  uint16_t balance = 0u;
};
 
struct NullMediaHeader : FullBox {
  DECLARE_BOX_METHODS(NullMediaHeader);
};
 
struct SubtitleMediaHeader : FullBox {
  DECLARE_BOX_METHODS(SubtitleMediaHeader);
};
 
struct DataEntryUrl : FullBox {
  DECLARE_BOX_METHODS(DataEntryUrl);
 
  std::vector<uint8_t> location;
};
 
struct DataReference : FullBox {
  DECLARE_BOX_METHODS(DataReference);
 
  // Can be either url or urn box. Fix to url box for now.
  std::vector<DataEntryUrl> data_entry = std::vector<DataEntryUrl>(1);
};
 
struct DataInformation : Box {
  DECLARE_BOX_METHODS(DataInformation);
 
  DataReference dref;
};
 
struct MediaInformation : Box {
  DECLARE_BOX_METHODS(MediaInformation);
 
  DataInformation dinf;
  SampleTable sample_table;
  // Exactly one specific meida header shall be present, vmhd, smhd, hmhd, nmhd.
  VideoMediaHeader vmhd;
  SoundMediaHeader smhd;
  NullMediaHeader nmhd;
  SubtitleMediaHeader sthd;
};
 
struct Media : Box {
  DECLARE_BOX_METHODS(Media);
 
  MediaHeader header;
  HandlerReference handler;
  MediaInformation information;
};
 
struct Track : Box {
  DECLARE_BOX_METHODS(Track);
 
  TrackHeader header;
  Media media;
  Edit edit;
  SampleEncryption sample_encryption;
};
 
struct MovieExtendsHeader : FullBox {
  DECLARE_BOX_METHODS(MovieExtendsHeader);
 
  uint64_t fragment_duration = 0u;
};
 
struct TrackExtends : FullBox {
  DECLARE_BOX_METHODS(TrackExtends);
 
  uint32_t track_id = 0u;
  uint32_t default_sample_description_index = 0u;
  uint32_t default_sample_duration = 0u;
  uint32_t default_sample_size = 0u;
  uint32_t default_sample_flags = 0u;
};
 
struct MovieExtends : Box {
  DECLARE_BOX_METHODS(MovieExtends);
 
  MovieExtendsHeader header;
  std::vector<TrackExtends> tracks;
};
 
struct Movie : Box {
  DECLARE_BOX_METHODS(Movie);
 
  MovieHeader header;
  Metadata metadata;  // Used to hold version information.
  MovieExtends extends;
  std::vector<Track> tracks;
  std::vector<ProtectionSystemSpecificHeader> pssh;
};
 
struct TrackFragmentDecodeTime : FullBox {
  DECLARE_BOX_METHODS(TrackFragmentDecodeTime);
 
  uint64_t decode_time = 0u;
};
 
struct MovieFragmentHeader : FullBox {
  DECLARE_BOX_METHODS(MovieFragmentHeader);
 
  uint32_t sequence_number = 0u;
};
 
struct TrackFragmentHeader : FullBox {
  enum TrackFragmentFlagsMasks {
    kBaseDataOffsetPresentMask = 0x000001,
    kSampleDescriptionIndexPresentMask = 0x000002,
    kDefaultSampleDurationPresentMask = 0x000008,
    kDefaultSampleSizePresentMask = 0x000010,
    kDefaultSampleFlagsPresentMask = 0x000020,
    kDurationIsEmptyMask = 0x010000,
    kDefaultBaseIsMoofMask = 0x020000,
  };
 
  enum SampleFlagsMasks {
    kReservedMask = 0xFC000000,
    kSampleDependsOnMask = 0x03000000,
    kSampleIsDependedOnMask = 0x00C00000,
    kSampleHasRedundancyMask = 0x00300000,
    kSamplePaddingValueMask = 0x000E0000,
    kNonKeySampleMask = 0x00010000,
    kSampleDegradationPriorityMask = 0x0000FFFF,
  };
 
  DECLARE_BOX_METHODS(TrackFragmentHeader);
 
  uint32_t track_id = 0u;
  uint32_t sample_description_index = 0u;
  uint32_t default_sample_duration = 0u;
  uint32_t default_sample_size = 0u;
  uint32_t default_sample_flags = 0u;
};
 
struct TrackFragmentRun : FullBox {
  enum TrackFragmentFlagsMasks {
    kDataOffsetPresentMask = 0x000001,
    kFirstSampleFlagsPresentMask = 0x000004,
    kSampleDurationPresentMask = 0x000100,
    kSampleSizePresentMask = 0x000200,
    kSampleFlagsPresentMask = 0x000400,
    kSampleCompTimeOffsetsPresentMask = 0x000800,
  };
 
  DECLARE_BOX_METHODS(TrackFragmentRun);
 
  uint32_t sample_count = 0u;
  uint32_t data_offset = 0u;
  std::vector<uint32_t> sample_flags;
  std::vector<uint32_t> sample_sizes;
  std::vector<uint32_t> sample_durations;
  std::vector<int64_t> sample_composition_time_offsets;
};
 
struct TrackFragment : Box {
  DECLARE_BOX_METHODS(TrackFragment);
 
  TrackFragmentHeader header;
  std::vector<TrackFragmentRun> runs;
  bool decode_time_absent = false;
  TrackFragmentDecodeTime decode_time;
  std::vector<SampleGroupDescription> sample_group_descriptions;
  std::vector<SampleToGroup> sample_to_groups;
  SampleAuxiliaryInformationSize auxiliary_size;
  SampleAuxiliaryInformationOffset auxiliary_offset;
  SampleEncryption sample_encryption;
};
 
struct MovieFragment : Box {
  DECLARE_BOX_METHODS(MovieFragment);
 
  MovieFragmentHeader header;
  std::vector<TrackFragment> tracks;
  std::vector<ProtectionSystemSpecificHeader> pssh;
};
 
struct SegmentReference {
  enum SAPType {
    TypeUnknown = 0,
    Type1 = 1,  // T(ept) = T(dec) = T(sap) = T(ptf)
    Type2 = 2,  // T(ept) = T(dec) = T(sap) < T(ptf)
    Type3 = 3,  // T(ept) < T(dec) = T(sap) <= T(ptf)
    Type4 = 4,  // T(ept) <= T(ptf) < T(dec) = T(sap)
    Type5 = 5,  // T(ept) = T(dec) < T(sap)
    Type6 = 6,  // T(ept) < T(dec) < T(sap)
  };
 
  bool reference_type = false;
  uint32_t referenced_size = 0u;
  uint32_t subsegment_duration = 0u;
  bool starts_with_sap = false;
  SAPType sap_type = TypeUnknown;
  uint32_t sap_delta_time = 0u;
  // We add this field to keep track of earliest_presentation_time in this
  // subsegment. It is not part of SegmentReference.
  uint64_t earliest_presentation_time = 0u;
};
 
struct SegmentIndex : FullBox {
  DECLARE_BOX_METHODS(SegmentIndex);
 
  uint32_t reference_id = 0u;
  uint32_t timescale = 0u;
  uint64_t earliest_presentation_time = 0u;
  uint64_t first_offset = 0u;
  std::vector<SegmentReference> references;
};
 
// The actual data is parsed and written separately.
struct MediaData : Box {
  DECLARE_BOX_METHODS(MediaData);
 
  uint32_t data_size = 0u;
};
 
// Using negative value as "not set". It is very unlikely that 2^31 cues happen
// at once.
const int kCueSourceIdNotSet = -1;
 
struct CueSourceIDBox : Box {
  DECLARE_BOX_METHODS(CueSourceIDBox);
 
  int32_t source_id = kCueSourceIdNotSet;
};
 
struct CueTimeBox : Box {
  DECLARE_BOX_METHODS(CueTimeBox);
 
  std::string cue_current_time;
};
 
struct CueIDBox : Box {
  DECLARE_BOX_METHODS(CueIDBox);
 
  std::string cue_id;
};
 
struct CueSettingsBox : Box {
  DECLARE_BOX_METHODS(CueSettingsBox);
 
  std::string settings;
};
 
struct CuePayloadBox : Box {
  DECLARE_BOX_METHODS(CuePayloadBox);
 
  std::string cue_text;
};
 
struct VTTEmptyCueBox : Box {
  DECLARE_BOX_METHODS(VTTEmptyCueBox);
};
 
struct VTTAdditionalTextBox : Box {
  DECLARE_BOX_METHODS(VTTAdditionalTextBox);
 
  std::string cue_additional_text;
};
 
struct VTTCueBox : Box {
  DECLARE_BOX_METHODS(VTTCueBox);
 
  CueSourceIDBox cue_source_id;
  CueIDBox cue_id;
  CueTimeBox cue_time;
  CueSettingsBox cue_settings;
  CuePayloadBox cue_payload;
};
 
#undef DECLARE_BOX
 
}  // namespace mp4
}  // namespace media
}  // namespace shaka
 
#endif  // PACKAGER_MEDIA_FORMATS_MP4_BOX_DEFINITIONS_H_