DecorrTerms

[wavpack.git] / Codec / Audio / WavPack / Metadata.hs

diff --git a/Codec/Audio/WavPack/Metadata.hs b/Codec/Audio/WavPack/Metadata.hs
index 77901f445aedf505ab7e4ce117ae026ebdd147c7..601d42e666b8d45b2e68be9b28b9424af5feafec 100644 (file)
--- a/Codec/Audio/WavPack/Metadata.hs
+++ b/Codec/Audio/WavPack/Metadata.hs
@@ -9,6 +9,9 @@ module Codec.Audio.WavPack.Metadata
     , SubBlock
 
     , Dummy(..)
+    , DecorrTerms(..)
+    , RIFFHeader(..)
+    , RIFFTrailer(..)
     , Unknown(..)
     )
     where
@@ -18,7 +21,9 @@ import Data.Binary.Get
 import Data.Binary.Put
 import Data.Bits
 import qualified Data.ByteString.Lazy as L
+import Data.Int
 import Data.Typeable
+import qualified Data.Vector.Unboxed as UV
 import Prelude.Unicode
 
 -- | Type class for every metadata sub-blocks.
@@ -85,7 +90,10 @@ instance Binary SubBlock where
              return $ runGet (getSubBlock rawID) subb
         where
           getSubBlock ∷ Word8 → Get SubBlock
-          getSubBlock 0x00 = fmap SubBlock (get ∷ Get Dummy)
+          getSubBlock 0x00 = fmap SubBlock (get ∷ Get Dummy      )
+          getSubBlock 0x02 = fmap SubBlock (get ∷ Get DecorrTerms)
+          getSubBlock 0x21 = fmap SubBlock (get ∷ Get RIFFHeader )
+          getSubBlock 0x22 = fmap SubBlock (get ∷ Get RIFFTrailer)
           getSubBlock unknownID
               = if unknownID .&. 0x20 ≡ 0 then
                     fail ("Unknown WavPack metadata ID: " ⧺ show unknownID)
@@ -117,6 +125,70 @@ instance Binary Dummy where
     put = putLazyByteString ∘ flip L.replicate 0x00 ∘ fromIntegral ∘ dumSize
     get = fmap (Dummy ∘ fromIntegral) remaining
 
+-- | Decorrelation terms and deltas.
+data DecorrTerms
+    = DecorrTerms {
+        -- | [ (term, delta) ]
+        dectVec ∷ !(UV.Vector (Int8, Int8))
+      }
+    deriving (Eq, Show, Typeable)
+
+instance Metadata DecorrTerms where
+    metaID _ = 0x02
+    metaSize = fromIntegral ∘ UV.length ∘ dectVec
+
+instance Binary DecorrTerms where
+    put = UV.mapM_ (putWord8 ∘ packDT) ∘ dectVec
+        where
+          packDT ∷ (Int8, Int8) → Word8
+          packDT (term, δ)
+              = fromIntegral ( (term + 5 .&. 0x1F)
+                               .|.
+                               ((δ `shiftL` 5) .&. 0xE0)
+                             )
+
+    get = do n   ← remaining
+             vec ← UV.replicateM (fromIntegral n) $ fmap unpackDT getWord8
+             -- THINKME: unpack.c(read_decorr_terms) reverses the
+             -- order only when they are decoding. I don't know why so
+             -- I leave it unreversed for now.
+             return $ DecorrTerms vec
+        where
+          unpackDT ∷ Word8 → (Int8, Int8)
+          unpackDT w
+              = let term = (fromIntegral $ w .&. 0x1F) - 5
+                    δ    = fromIntegral $ (w `shiftR` 5) .&. 0x07
+                in
+                  (term, δ)
+
+-- | RIFF header for .wav files (before audio)
+data RIFFHeader
+    = RIFFHeader {
+        riffHeader ∷ L.ByteString
+      }
+    deriving (Eq, Show, Typeable)
+
+instance Metadata RIFFHeader where
+    metaID _ = 0x21
+
+instance Binary RIFFHeader where
+    put = putLazyByteString ∘ riffHeader
+    get = fmap RIFFHeader getRemainingLazyByteString
+
+-- | RIFF trailer for .wav files (after audio)
+data RIFFTrailer
+    = RIFFTrailer {
+        riffTrailer ∷ L.ByteString
+      }
+    deriving (Eq, Show, Typeable)
+
+instance Metadata RIFFTrailer where
+    metaID _ = 0x22
+
+instance Binary RIFFTrailer where
+    put = putLazyByteString ∘ riffTrailer
+    get = fmap RIFFTrailer getRemainingLazyByteString
+
 -- | Unknown but optional metadata found in the WavPack block.
 data Unknown
     = Unknown {
@@ -130,8 +202,7 @@ data Unknown
 
 instance Metadata Unknown where
     metaID   = unkID
-    metaSize = fromIntegral ∘ L.length ∘ unkData
 
 instance Binary Unknown where
     put = putLazyByteString ∘ unkData
-    get = (⊥)
+    get = error "unsupported operation"