findNextBlock

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

diff --git a/Codec/Audio/WavPack/Metadata.hs b/Codec/Audio/WavPack/Metadata.hs
index 78a99fc5e232dd7e168c971d30d1209a80cd92de..77901f445aedf505ab7e4ce117ae026ebdd147c7 100644 (file)
--- a/Codec/Audio/WavPack/Metadata.hs
+++ b/Codec/Audio/WavPack/Metadata.hs
@@ -23,9 +23,11 @@ import Prelude.Unicode
 
 -- | 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).
@@ -48,18 +50,19 @@ instance Metadata SubBlock where
 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
 
@@ -117,7 +120,8 @@ instance Binary Dummy where
 -- | Unknown but optional metadata found in the WavPack block.
 data Unknown
     = Unknown {
-        -- | The ID of this unknown metadata.
+        -- | 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