conduit-audio (empty) → 0.1
raw patch · 4 files changed
+860/−0 lines, 4 filesdep +basedep +conduitdep +vectorsetup-changed
Dependencies added: base, conduit, vector
Files
- LICENSE +507/−0
- Setup.hs +2/−0
- conduit-audio.cabal +40/−0
- src/Data/Conduit/Audio.hs +311/−0
+ LICENSE view
@@ -0,0 +1,507 @@+ GNU LESSER GENERAL PUBLIC LICENSE+ Version 2.1, February 1999++ Copyright (C) 1991, 1999 Free Software Foundation, Inc.+ 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA+ Everyone is permitted to copy and distribute verbatim copies+ of this license document, but changing it is not allowed.++[This is the first released version of the Lesser GPL. It also counts+ as the successor of the GNU Library Public License, version 2, hence+ the version number 2.1.]++ Preamble++ The licenses for most software are designed to take away your+freedom to share and change it. By contrast, the GNU General Public+Licenses are intended to guarantee your freedom to share and change+free software--to make sure the software is free for all its users.++ This license, the Lesser General Public License, applies to some+specially designated software packages--typically libraries--of the+Free Software Foundation and other authors who decide to use it. 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+ Setup.hs view
@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain
+ conduit-audio.cabal view
@@ -0,0 +1,40 @@+name: conduit-audio+version: 0.1+author: Michael Tolly+maintainer: miketolly@gmail.com+license: LGPL+license-file: LICENSE+category: Sound+build-type: Simple+cabal-version: >= 1.10+homepage: http://github.com/mtolly/conduit-audio+bug-reports: http://github.com/mtolly/conduit-audio/issues+synopsis: Combinators to efficiently slice and dice audio streams+description:+ @conduit-audio@ applies @conduit@'s streaming data abilities+ to efficiently manipulate audio files and streams.+ Simple combinator functions let you mix files together,+ cut and paste sections of audio,+ and apply more complicated transformations like resampling or timestretching,+ all with the following properties:+ .+ * Tiny memory usage, proportional only to the number of simultaneous sources\/effects+ .+ * Uses no temporary files; everything is done in one pass+ .+ * Blazing fast! (for most uses)++library+ exposed-modules:+ Data.Conduit.Audio+ build-depends:+ base >= 4.6 && < 4.8+ , conduit+ , vector+ hs-source-dirs: src+ default-language: Haskell2010+ ghc-options: -Wall -O2++source-repository head+ type: git+ location: http://github.com/mtolly/conduit-audio
+ src/Data/Conduit/Audio.hs view
@@ -0,0 +1,311 @@+{- |+A high-level functional interface for manipulating streams of audio.+-}+module Data.Conduit.Audio+( -- * Types+ AudioSource(..)+, Seconds, Frames, Rate, Channels, Duration(..)+ -- * Generating audio+, silent, sine+ -- * Combining audio+, concatenate, mix, merge, splitChannels+ -- * Editing audio+, padStart, padEnd+, takeStart, takeEnd+, dropStart, dropEnd+, fadeIn, fadeOut+, mapSamples, gain+ -- * Utility functions+, vectorFrames+, framesToSeconds, secondsToFrames+, chunkSize+, deinterleave, interleave+, integralSample, fractionalSample+) where++import qualified Data.Vector.Storable as V+import qualified Data.Conduit as C+import Data.Conduit ((=$=))+import qualified Data.Conduit.List as CL+import Data.Conduit.Internal (zipSources)+import Control.Monad (replicateM_, forever, when)+import Data.Maybe (fromMaybe)+import Text.Printf (printf)++-- | An abstraction of a stream of audio. Inside is a Conduit 'C.Source' which+-- loads or generates smallish chunks of audio on demand. @m@ is the 'Monad'+-- used by the 'C.Source' to produce audio. @a@ is the type of audio samples,+-- contained in storable vectors (and thus should be 'V.Storable').+-- Both (signed) 'Integral' and 'Fractional' sample types are supported.+data AudioSource m a = AudioSource+ { source :: C.Source m (V.Vector a)+ -- ^ The stream of audio chunks; samples interleaved by channel.+ -- Each chunk can be any positive whole number of frames.+ , rate :: Rate+ , channels :: Channels+ , frames :: Frames+ -- ^ The stated length in frames of this audio stream.+ -- Not guaranteed to be exactly frame-accurate;+ -- the output of some operations like resampling or time-stretching+ -- may store only approximate frame counts.+ }++-- | A duration in real time.+type Seconds = Double+-- | A frame consists of one sample for each audio channel.+type Frames = Int+-- | The number of samples per second.+type Rate = Double+-- | The number of audio channels (1 = mono, 2 = stereo, etc.)+type Channels = Int++-- | Used for functions that accept durations in either real time or audio frames.+data Duration+ = Seconds Seconds+ | Frames Frames+ deriving (Eq, Ord, Show, Read)++-- | Divides the vector length by the channel count to calculate the number of audio frames.+vectorFrames :: (V.Storable a) => V.Vector a -> Channels -> Frames+vectorFrames v c = case quotRem (V.length v) c of+ (len, 0) -> len+ _ -> error $+ printf "Data.Conduit.Audio.vectorFrames: block length (%d) not divisible by channel count (%d)"+ (V.length v) c++-- | Uses the sample rate to convert frames to seconds.+framesToSeconds :: Frames -> Rate -> Seconds+framesToSeconds fms r = fromIntegral fms / r++-- | Uses the sample rate to convert seconds to frames, rounding if necessary.+secondsToFrames :: Seconds -> Rate -> Frames+secondsToFrames secs r = round $ secs * r++-- | An arbitrary size, in frames, for smallish audio chunks.+chunkSize :: Frames+chunkSize = 10000++-- | Generates a stream of silence with the given parameters.+silent :: (Monad m, Num a, V.Storable a) => Duration -> Rate -> Channels -> AudioSource m a+silent (Seconds secs) r c = silent (Frames $ secondsToFrames secs r) r c+silent (Frames fms) r c = let+ (full, part) = quotRem fms chunkSize+ fullChunk = V.replicate (chunkSize * c) 0+ partChunk = V.replicate (part * c) 0+ src = do+ replicateM_ full $ C.yield fullChunk+ when (part /= 0) $ C.yield partChunk+ in AudioSource src r c fms++-- | Generates a mono sine wave with the given frequency.+sine :: (Monad m, Floating a, V.Storable a) => a -> Duration -> Rate -> AudioSource m a+sine freq (Seconds secs) r = sine freq (Frames $ secondsToFrames secs r) r+sine freq (Frames fms) r = AudioSource (go 0) r 1 fms where+ valueAt posn = sin $ 2 * pi * freq * (fromIntegral posn / realToFrac r)+ go posn = let+ left = fms - posn+ in if left <= chunkSize+ then C.yield $ V.generate left $ \i -> valueAt $ i + posn+ else let+ firstChunk = V.generate chunkSize $ \i -> valueAt $ i + posn+ in C.yield firstChunk >> go (posn + chunkSize)++-- | Connects the end of the first audio source to the beginning of the second.+-- The two sources must have the same sample rate and channel count.+concatenate :: (Monad m) => AudioSource m a -> AudioSource m a -> AudioSource m a+concatenate (AudioSource s1 r1 c1 l1) (AudioSource s2 r2 c2 l2)+ | r1 /= r2 = error $+ printf "Data.Conduit.Audio.concatenate: mismatched rates (%d and %d)" r1 r2+ | c1 /= c2 = error $+ printf "Data.Conduit.Audio.concatenate: mismatched channel counts (%d and %d)" c1 c2+ | otherwise = AudioSource (s1 >> s2) r1 c1 (l1 + l2)++padStart, padEnd :: (Monad m, Num a, V.Storable a) => Duration -> AudioSource m a -> AudioSource m a+-- | Adds silence to the start of the audio stream.+padStart d src@(AudioSource _ r c _) = concatenate (silent d r c) src+-- | Adds silence to the end of the audio stream.+padEnd d src@(AudioSource _ r c _) = concatenate src (silent d r c)++-- | Splits an audio stream into several, each providing a single channel of the original stream.+splitChannels :: (Monad m, V.Storable a) => AudioSource m a -> [AudioSource m a]+splitChannels (AudioSource src r c l) = do+ i <- [0 .. c - 1]+ let src' = src =$= CL.map (\v -> deinterleave c v !! i)+ return $ AudioSource src' r 1 l++-- | Mixes two audio streams together by adding them samplewise.+-- The two streams must have the same sample rate and channel count.+-- It is recommended to only mix floating-point sample types.+-- If you mix integral types and the result goes outside of the type's range,+-- the result will not be a normal \"clipping\" effect, but will instead overflow,+-- producing glitchy audio.+mix :: (Monad m, Num a, V.Storable a) => AudioSource m a -> AudioSource m a -> AudioSource m a+mix (AudioSource s1 r1 c1 l1) (AudioSource s2 r2 c2 l2)+ | r1 /= r2 = error $+ printf "Data.Conduit.Audio.mix: mismatched rates (%d and %d)" r1 r2+ | c1 /= c2 = error $+ printf "Data.Conduit.Audio.mix: mismatched channel counts (%d and %d)" c1 c2+ | otherwise = AudioSource+ (combineAudio c1 c2 s1 s2 =$= CL.map (uncurry $ V.zipWith (+)))+ r1 c1 (max l1 l2)++-- | Combines the channels of two audio streams into a single source with all the channels.+-- The two streams must have the same sample rate, but can have any number of channels.+merge :: (Monad m, Num a, V.Storable a) => AudioSource m a -> AudioSource m a -> AudioSource m a+merge (AudioSource s1 r1 c1 l1) (AudioSource s2 r2 c2 l2)+ | r1 /= r2 = error $+ printf "Data.Conduit.Audio.merge: mismatched rates (%d and %d)" r1 r2+ | otherwise = AudioSource+ (combineAudio c1 c2 s1 s2 =$= CL.map+ (\(p1, p2) -> interleave $ deinterleave c1 p1 ++ deinterleave c2 p2))+ r1 (c1 + c2) (max l1 l2)++-- | Applies a function to every sample in the audio stream.+mapSamples :: (Monad m, V.Storable a, V.Storable b) =>+ (a -> b) -> AudioSource m a -> AudioSource m b+mapSamples f (AudioSource s r c l) = AudioSource (s =$= CL.map (V.map f)) r c l++-- | Multiplies all the audio samples by the given scaling factor.+-- It is best to use this function on floating-point sample types,+-- for the same reasons that apply to 'mix'.+gain :: (Monad m, Num a, V.Storable a) => a -> AudioSource m a -> AudioSource m a+gain d = mapSamples (* d)++-- | Fades the audio from start (silent) to end (original volume).+-- This function relies on the 'frames' value stored with the stream.+fadeIn :: (Monad m, Ord a, Fractional a, V.Storable a) => AudioSource m a -> AudioSource m a+fadeIn (AudioSource s r c l) = let+ go i = C.await >>= \mx -> case mx of+ Nothing -> return ()+ Just v -> let+ fader = V.generate (V.length v) $ \j ->+ min 1 $ fromIntegral (i + quot j c) / fromIntegral l+ in C.yield (V.zipWith (*) v fader) >> go (i + vectorFrames v c)+ in AudioSource (s =$= go 0) r c l++-- | Fades the audio from start (original volume) to end (silent).+-- This function relies on the 'frames' value stored with the stream.+fadeOut :: (Monad m, Ord a, Fractional a, V.Storable a) => AudioSource m a -> AudioSource m a+fadeOut (AudioSource s r c l) = let+ go i = C.await >>= \mx -> case mx of+ Nothing -> return ()+ Just v -> let+ fader = V.generate (V.length v) $ \j ->+ 1 - (min 1 $ fromIntegral (i + quot j c) / fromIntegral l)+ in C.yield (V.zipWith (*) v fader) >> go (i + vectorFrames v c)+ in AudioSource (s =$= go 0) r c l++-- | Takes no more than the given duration of audio from the start of the stream.+takeStart :: (Monad m, V.Storable a) => Duration -> AudioSource m a -> AudioSource m a+takeStart (Seconds secs) src = takeStart (Frames $ secondsToFrames secs $ rate src) src+takeStart (Frames fms) (AudioSource src r c l) = let+ go left = C.await >>= \mx -> case mx of+ Nothing -> return ()+ Just v -> let+ len = V.length v+ in case compare left len of+ EQ -> C.yield v+ LT -> C.yield $ V.take left v+ GT -> C.yield v >> go (left - len)+ in AudioSource (src =$= go (fms * c)) r c (min l fms)++-- | Drops the given duration of audio from the start of the stream.+dropStart :: (Monad m, V.Storable a) => Duration -> AudioSource m a -> AudioSource m a+dropStart (Seconds secs) src = dropStart (Frames $ secondsToFrames secs $ rate src) src+dropStart (Frames fms) (AudioSource src r c l) = let+ go left = C.await >>= \mx -> case mx of+ Nothing -> return ()+ Just v -> let+ len = V.length v+ in case compare left len of+ EQ -> CL.map id+ LT -> C.yield (V.drop left v) >> CL.map id+ GT -> go (left - len)+ in AudioSource (src =$= go (fms * c)) r c (max 0 $ l - fms)++takeEnd, dropEnd :: (Monad m, V.Storable a) => Duration -> AudioSource m a -> AudioSource m a+-- | Takes no more than the given duration of audio from the end of the stream.+-- This function relies on the 'frames' value stored with the stream.+takeEnd (Frames fms) src = dropStart (Frames $ frames src - fms) src+takeEnd (Seconds secs) src = takeEnd (Frames $ secondsToFrames secs $ rate src) src+-- | Drops the given duration of audio from the end of the stream.+-- This function relies on the 'frames' value stored with the stream.+dropEnd (Frames fms) src = takeStart (Frames $ frames src - fms) src+dropEnd (Seconds secs) src = dropEnd (Frames $ secondsToFrames secs $ rate src) src++-- | Given a vector with interleaved samples, like @[L0, R0, L1, R1, ...]@,+-- converts it into @[[L0, L1, ...], [R0, R1, ...]]@.+deinterleave :: (V.Storable a) => Channels -> V.Vector a -> [V.Vector a]+deinterleave n v = do+ let len = V.length v `div` n+ i <- [0 .. n - 1]+ return $ V.generate len $ \j -> v V.! (n * j + i)++-- | Opposite of 'deinterleave'.+-- All the input vectors should have the same length.+interleave :: (V.Storable a) => [V.Vector a] -> V.Vector a+interleave vs = let+ n = length vs+ in V.generate (sum $ map V.length vs) $ \i -> let+ (q, r) = quotRem i n+ in (vs !! r) V.! q++-- | Combines two audio streams to produce pairs of same-length (in frames) chunks.+-- If one stream is shorter, its end will be padded with silence to match the longer one.+-- This function is used to implement 'mix' and 'merge'.+combineAudio+ :: (Num a, V.Storable a, Monad m)+ => Int+ -> Int+ -> C.Source m (V.Vector a)+ -> C.Source m (V.Vector a)+ -> C.Source m (V.Vector a, V.Vector a)+combineAudio c1 c2 s1 s2 = let+ justify src = (src =$= CL.map Just) >> forever (C.yield Nothing)+ await' = C.await >>= \mx -> case mx of+ Nothing -> error+ "Data.Conduit.Audio.combineAudio: internal error! reached end of infinite stream"+ Just x -> return x+ in zipSources (justify s1) (justify s2) =$= let+ loop = await' >>= \pair -> case pair of+ (Nothing, Nothing) -> return ()+ (Just v1, Nothing) -> let+ v2 = V.replicate (vectorFrames v1 c1 * c2) 0+ in C.yield (v1, v2) >> loop+ (Nothing, Just v2) -> let+ v1 = V.replicate (vectorFrames v2 c2 * c1) 0+ in C.yield (v1, v2) >> loop+ (Just v1, Just v2) -> case compare (vectorFrames v1 c1) (vectorFrames v2 c2) of+ EQ -> C.yield (v1, v2) >> loop+ LT -> let+ (v2a, v2b) = V.splitAt (vectorFrames v1 c1 * c2) v2+ in C.yield (v1, v2a) >> await' >>= \(next1, next2) -> do+ C.leftover (next1, Just $ v2b V.++ fromMaybe V.empty next2)+ loop+ GT -> let+ (v1a, v1b) = V.splitAt (vectorFrames v2 c2 * c1) v1+ in C.yield (v1a, v2) >> await' >>= \(next1, next2) -> do+ C.leftover (Just $ v1b V.++ fromMaybe V.empty next1, next2)+ loop+ in loop++-- See http://blog.bjornroche.com/2009/12/int-float-int-its-jungle-out-there.html+-- for a discussion of different int/float sample conversion methods.+-- The ones below multiply/divide by 0x7FFF (or equivalent).+-- Int16 -> Float -> Int16 conversions are transparent:+-- all (\i -> i == integralSample (fractionalSample i :: Float)) [minBound :: Int16 .. maxBound]++-- | Converts fractional samples in the range @[-1, 1]@ to integral samples+-- in a two's-complement type. Fractional samples beyond that range are clamped.+integralSample :: (RealFrac a, Integral b, Bounded b) => a -> b+integralSample x+ | x <= (-1) = minBound+ | x >= 1 = maxBound+ | otherwise = let+ result = round $ x * fromIntegral (maxBound `asTypeOf` result)+ in result++-- | Converts integral samples in a two's-complement type to fractional+-- samples in the range @[-1, 1]@.+fractionalSample :: (Integral a, Bounded a, Fractional b) => a -> b+fractionalSample x = fromIntegral x / fromIntegral (maxBound `asTypeOf` x)