riff_AVIOLDINDEX {
  fcc           32 FOURCC
  cb            32 DWORD
  struct _avioldindex_entry {
    dwChunkId   32 DWORD
    dwFlags     32 DWORD
    dwOffset    32 DWORD
    dwSize      32 DWORD
  } aIndex[]
}

Add index chunk definition of RIFF.
Add index chunk definition of RIFF.
