-- | Type class for every metadata sub-blocks.
class (Binary α, Eq α, Show α, Typeable α) ⇒ Metadata α where
- -- | Get the metadata ID (mandatory).
+ -- | Get the metadata ID without odd-size bit nor large-block bit
+ -- (mandatory).
metaID ∷ α → Word8
- -- | Get the size of metadata (optional).
+ -- | Get the size of metadata, excluding the metadata header
+ -- (optional).
metaSize ∷ α → Word32
metaSize = fromIntegral ∘ L.length ∘ runPut ∘ put
-- | Cast a 'SubBlock' to this type of metadata (optional).
instance Binary SubBlock where
put (SubBlock a)
= let size = metaSize a
- oddBit = if odd size then 0x40 else 0
- largeBit = if size > 255 then 0x80 else 0
+ size' = size + 1
+ oddBit = if odd size then 0x40 else 0
+ largeBit = if size > 0x1FE then 0x80 else 0
idWord = metaID a .|. oddBit .|. largeBit
in
do putWord8 idWord
- if size > 255 then
+ if size > 0x1FE then
-- Don't forget about the endianness.
- do putWord8 $ fromIntegral $ (size `shiftR` 1) .&. 0xFF
- putWord8 $ fromIntegral $ (size `shiftR` 9) .&. 0xFF
- putWord8 $ fromIntegral $ (size `shiftR` 17) .&. 0xFF
+ do putWord8 $ fromIntegral $ (size' `shiftR` 1) .&. 0xFF
+ putWord8 $ fromIntegral $ (size' `shiftR` 9) .&. 0xFF
+ putWord8 $ fromIntegral $ (size' `shiftR` 17) .&. 0xFF
else
- putWord8 $ fromIntegral $ (size `shiftR` 1) .&. 0xFF
+ putWord8 $ fromIntegral $ (size' `shiftR` 1) .&. 0xFF
put a
when (odd size) $ putWord8 0
-- | Dummy metadata to pad WavPack blocks.
data Dummy
= Dummy {
+ -- | Must be less than 2^25 bytes long due to the limitation
+ -- of WavPack specification.
dumSize ∷ Word32
}
deriving (Eq, Show, Typeable)
-- | Unknown but optional metadata found in the WavPack block.
data Unknown
= Unknown {
+ -- | The ID of this unknown metadata without odd-size bit nor
+ -- large-block bit.
unkID ∷ Word8
+ -- | Raw data; must be less than 2^25 bytes long.
, unkData ∷ L.ByteString
}
deriving (Eq, Show, Typeable)