soundmetadata.bin

Binary AudioKinetic metadata file. This file is present in DOOM Eternal and DOOM: The Dark Ages. However, their contents are very different (despite maintaining the same basic chunking structure)

The following is the file format for Dark Ages

// All values are Little-Endian

template<typename TYPE>
struct list_t {
	uint32_t num;
	TYPE* data;
}

struct string_t {
	uint32_t length;
    char* data; // Not null-terminated
}

// Case-insensitive (to lowercase) FNV hash
typedef uint32_t hash_t; 

struct NameHash {
  string_t name;
  hash_t hash; // Hash of the above string
}

// This file loves to flip-flop between putting
// a string after it's hash, or before it's hash
struct HashName {
  hash_t hash; // Hash of the following string
  string_t name;
}

struct SoundEvent {
  NameHash name;
  uint8_t languageID; // 0 corresponds with "SFX" and 1 with "ENGLISH(US)"
  string_t languageString;
}

// Sections 4 and 5 of the soundmetadata have
// the exact same format. Hence we can reuse 
// the same structure definitions for convenience
struct Section_4_5_Item {
  HashName name;
  list_t<HashName> stringlist;
}

struct SampleList_PlaybackTimes {
  string_t languageString;
  float playbackTime; // Playback time of the sample in seconds
}

struct SampleList_Sample {
  uint32_t sampleID;
  string_t languageString; // Language name, NOT the hashed string corresponding to the sampleID
}

// Can be used to identify which audio samples are used
// in which soundbanks
struct SampleList {
  NameHash name; // Name of a soundbank
  uint8_t byte; // Always 0
  uint32_t word; // Unknown
  uint8_t flag0; // 0 or 1
  uint8_t flag1; // 0 or 1
  uint32_t word2; // Unknown
  
  // IMPORTANT: This list (including it's length field)
  // is present ONLY IF flag0 == 0
  // Only present in non-SFX sample lists
  list_t<SampleList_PlaybackTimes> playbackTimes;
  
  list_t<SampleList_Sample> samples;
}

struct SoundMetaData_DarkAges {
  
  list_t<SoundEvent> SoundEvents;
  list_t<HashName> section2; // Exact purpose unknown
  list_t<NameHash> section3; // Exact purpose unknown
  list_t<Section_4_5_Item> SoundSwitches;
  list_t<Section_4_5_Item> SoundStates;
  list_t<SampleList> SampleLists;
  
  // See https://wiki.eternalmods.com/books/8-reverse-engineering-file-formats/page/containermask
  // For an explanation of this structure.
  sndContainerMask ContainerMask
}