Definition compressionSectionIdentifier (c : compressionMethod) : nat :=
  match c with
  | CompressionUncompressed       => 0
  | CompressionBC1                => 0
  | CompressionBC2                => 0
  | CompressionBC3                => 0
  | CompressionBC4                => 0
  | CompressionBC5                => 0
  | CompressionBC6                => 0
  | CompressionBC7                => 0
  | CompressionETC1               => 0
  | CompressionETC2               => 0
  | CompressionEAC                => 0
  | CompressionASTC _ _           => 0
  | CompressionCustom _ _ _ i _ _ => i
  end.
