gm_iff_audo.ksy

meta:
  id: gm_iff_audo
  file-extension:
    - win
    - dat
  imports:
    - /media/wav
    - /media/ogg
  title: "GameMaker: Studio WAD (sound-related chunks only, bytecode 14+)"
  license: CC0-1.0
  ks-version: 0.10
  endian: le
doc-ref: https://github.com/UnderminersTeam/UndertaleModTool

seq:
  - id: root
    type: chunk
    valid:
      expr: _.four_cc == chunk_type::form
instances:
  subchunks:
    value: root.data.as<chunks>.entries

types:
  chunks:
    seq:
      - id: entries
        type: chunk
        repeat: eos
  chunk:
    seq:
      - id: four_cc
        type: u4
        enum: chunk_type
      - id: size
        type: u4
      - id: data
        size: size
        type:
          switch-on: four_cc
          cases:
            "chunk_type::form": chunks
            "chunk_type::sond": pointer_list
            "chunk_type::agrp": pointer_list
            "chunk_type::audo": pointer_list
            _: dummy
    -webide-representation: "{fourCc}"

  dummy: {}

  pointer_list:
    seq:
      - id: length
        type: u4
      - id: entries_ofs
        type: u4
        repeat: expr
        repeat-expr: length
    instances:
      entries:
        repeat: expr
        repeat-expr: length
        type: pointer_list_item(_index)
  pointer_list_item:
    params:
      - id: i
        type: s4
    instances:
      body:
        io: _root._io
        pos: _parent.entries_ofs[i]
        type:
          switch-on: _parent._parent.four_cc
          cases:
            "chunk_type::sond": sound
            "chunk_type::agrp": audio_group
            "chunk_type::audo": embedded_audio
    -webide-representation: "{body}"

  gm_string_ref:
    seq:
      - id: str
        type: strz
        encoding: UTF-8
    -webide-representation: "{str}"

  sound:
    seq:
      - id: name_ofs
        type: u4
      - id: flags
        type: u4
        valid:
          expr: "(_ & 0x64) == 0x64"
      - id: type_ofs
        type: u4
      - id: filename_ofs
        type: u4
      - id: effects
        type: u4
      - id: volume
        type: f4
      - id: unknown
        type: f4
      - id: audio_group_id
        type: u4
      - id: file_id
        type: s4
    instances:
      name_obj:
        io: _root._io
        if: name_ofs != 0
        pos: name_ofs
        type: gm_string_ref
      name:
        if: name_obj
        value: name_obj.str
      embedded:
        value: "(flags & 0x1) == 0x1"
      compressed:
        value: "(flags & 0x2) == 0x2"
      decompressed_on_load:
        value: "(flags & 0x3) == 0x3"
      type_obj:
        io: _root._io
        if: type_ofs != 0
        pos: type_ofs
        type: gm_string_ref
      type:
        if: type_obj
        value: type_obj.str
      filename_obj:
        io: _root._io
        if: filename_ofs != 0
        pos: filename_ofs
        type: gm_string_ref
      filename:
        if: filename_obj
        value: filename_obj.str
      audio_group_filename:
        if: "audio_group_id != 0"
        value: "\"audiogroup\" + audio_group_id.to_s + \".dat\""
    -webide-representation: "{name}"

  audio_group:
    seq:
      - id: name_ofs
        type: u4
    instances:
      name_obj:
        io: _root._io
        pos: name_ofs
        if: name_ofs != 0
        type: gm_string_ref
      name:
        if: name_obj
        value: name_obj.str
    -webide-representation: "{name}"

  embedded_audio:
    seq:
      - id: size
        type: u4
      - id: data
        size: size
        type: embedded_audio_data
  embedded_audio_data:
    seq:
      - id: data
        type:
          switch-on: magic
          cases:
            "sound_data_magic::riff": wav
            "sound_data_magic::oggs": ogg
            _: wav
    instances:
      magic:
        pos: 0
        type: u4
        enum: sound_data_magic

enums:
  chunk_type:
    0x4d524f46: form
    0x444e4f53: sond
    0x50524741: agrp
    0x4f445541: audo

  sound_data_magic:
    0x52494646: riff
    0x5367674f: oggs