From: PHO Date: Mon, 25 Jul 2011 15:04:25 +0000 (+0900) Subject: still working on decorrStereoPass X-Git-Url: https://git.cielonegro.org/gitweb.cgi?a=commitdiff_plain;h=refs%2Fheads%2Fmaster;p=wavpack.git still working on decorrStereoPass --- diff --git a/Codec/Audio/WavPack/Decorrelation.hs b/Codec/Audio/WavPack/Decorrelation.hs index 0230244..3e2271e 100644 --- a/Codec/Audio/WavPack/Decorrelation.hs +++ b/Codec/Audio/WavPack/Decorrelation.hs @@ -14,7 +14,6 @@ import Control.Monad.ST import Data.Bits import Data.Int import Data.STRef -import qualified Data.Strict as S import qualified Data.Vector.Generic.Mutable as MV import Prelude.Unicode @@ -36,11 +35,11 @@ data DecorrPass v s , dpWeightA ∷ !(STRef s Int16) -- | The decorrelation weight for channel B: @-1024 <= weight <= -- 1024@ - , dpWeightB ∷ !(S.Maybe (STRef s Int16)) + , dpWeightB ∷ !(STRef s Int16) -- | The decorrelation samples for channel A. , dpSamplesA ∷ !(v s Int32) -- | The decorrelation samples for channel B. - , dpSamplesB ∷ !(S.Maybe (v s Int32)) + , dpSamplesB ∷ !(v s Int32) } -- |General function to perform stereo decorrelation pass on specified @@ -55,14 +54,31 @@ decorrStereoPass ∷ ∀v s. MV.MVector v Int32 → ST s () {-# INLINEABLE decorrStereoPass #-} decorrStereoPass dp buffer + | MV.length buffer `rem` 2 ≢ 0 + = fail "decorrStereoPass: assertion failed: MV.length buffer `rem` 2 ≡ 0" | dpTerm dp ≡ 17 = flip mapM_ [0 .. (MV.length buffer `div` 2) - 1] $ \n → do a0 ← MV.unsafeRead (dpSamplesA dp) 0 a1 ← MV.unsafeRead (dpSamplesA dp) 1 - let samA = 2 ⋅ a0 - a1 MV.unsafeWrite (dpSamplesA dp) 1 a0 tmpA ← MV.unsafeRead buffer (n ⋅ 2) - fail "FIXME" + weiA ← readSTRef (dpWeightA dp) + let samA = 2 ⋅ a0 - a1 + samA' = applyWeight weiA samA + tmpA + MV.unsafeWrite (dpSamplesA dp) 0 samA' + MV.unsafeWrite buffer (n ⋅ 2) samA' + writeSTRef (dpWeightA dp) $ updateWeight weiA (dpDelta dp) tmpA samA + + b0 ← MV.unsafeRead (dpSamplesB dp) 0 + b1 ← MV.unsafeRead (dpSamplesB dp) 1 + MV.unsafeWrite (dpSamplesB dp) 1 b0 + tmpB ← MV.unsafeRead buffer (n ⋅ 2 + 1) + weiB ← readSTRef (dpWeightB dp) + let samB = 2 ⋅ b0 - b1 + samB' = applyWeight weiB samB + tmpB + MV.unsafeWrite (dpSamplesB dp) 0 samB' + MV.unsafeWrite buffer (n ⋅ 2 + 1) samB' + writeSTRef (dpWeightB dp) $ updateWeight weiB (dpDelta dp) tmpB samB | otherwise = fail "FIXME" @@ -76,3 +92,13 @@ applyWeight weight sample (((sample .&. complement 0xFFFF) `shiftR` 9) ⋅ fromIntegral weight) + 1 ) `shiftR` 1 + +updateWeight ∷ Int16 → Int8 → Int32 → Int32 → Int16 +{-# INLINE updateWeight #-} +updateWeight weight δ source result + | source ≢ 0 ∧ result ≢ 0 + = let s = fromIntegral $ (source `xor` result) `shiftR` 31 + in + (fromIntegral δ `xor` s) + (weight - s) + | otherwise + = weight