Data.Array.Repa.IO.Sndfile

Read and write audio file with repa arrays using libsndfile via hsndfile. Note that this module re-exports header related types from hsndfile.

For more info about supported format, visit libsndfile web site:

• libsndfile: http://www.mega-nerd.com/libsndfile/
• hsndfile http://haskell.org/haskellwiki/Hsndfile

Examples

Read "in.wav", write to "out.wav" with same format.

 module Main where

 import Data.Array.Repa
   ((:.)(..), Array, Z(..), DIM2, computeP, fromFunction)
 import Data.Array.Repa.Repr.ForeignPtr (F)
 import Data.Array.Repa.IO.Sndfile

 main :: IO ()
 main = do
   (i, a) <- readSF "in.wav" :: IO (Info, Array F DIM2 Double)
   writeSF "out.wav" i a

Write 440hz sine wave for 3 seconds to monaural file "sin440.wav".

 sin440 :: IO ()
 sin440 = do
   let dur = 3; freq = 440; sr = 48000
       hdr = wav16 {samplerate = sr, frames = sr * dur}
       sig = fromFunction (Z :. 1 :. dur * sr) $ \(_ :. _ :. i) ->
         sin (fromIntegral i * freq * pi * 2 / fromIntegral sr)
   sig' <- computeP sig :: IO (Array F DIM2 Double)
   writeSF "sin440.wav" hdr sig'

Write 440hz sine wave to channel 0, 880hz sine wave to channel 1, for 3 seconds to stereo file "sin440and880.wav".

 sin440and880 :: IO ()
 sin440and880 = do
     let dur = 3; freq1 = 440; freq2 = 880; sr = 480000
         hdr = wav16 {samplerate = sr, channels = 2, frames = sr * dur * 2}
         gen f i = sin (fromIntegral i * f * pi * 2 / fromIntegral sr)
         sig = fromFunction (Z :. 2 :. dur * sr) $ \(_ :. c :. i) ->
             case c of
                 0 -> gen freq1 i
                 1 -> gen freq2 i
                 _ -> 0
     sig' <- computeP sig :: IO (Array F DIM2 Double)
     writeSF "sin440and880.wav" hdr sig'

Sound file reader and writer

readSF :: forall a r. (Sample a, Source r a, Target r a, Buffer (Array F DIM1) a) => FilePath -> IO (Info, Array r DIM2 a)

Read sound file from given path.

Returns a tuple of Info and array containing the samples of sound file. Returned pair contains sound file information and array which is indexed with channel number and frame. Info could used later for writing sound file.

writeSF :: forall a r. (Sample a, Source r a, Buffer (Array r DIM1) a, Target r a) => FilePath -> Info -> Array r DIM2 a -> IO ()

Write array contents to sound file with given header information.

Expecting an array indexed with channel and frame, as returned from readSF. i.e. 2-dimensional array with its contents indexed with channel.

withSF :: forall a b r. (Sample a, Target r a, Source r a) => FilePath -> (Info -> Array r DIM2 a -> IO b) -> IO b

Wrapper for invoking array with reading sound file.

Performs given action using sound file info and samples as arguments.

Sound file headers (re-exports from hsndfile)

data Info

The Info structure is for passing data between the calling function and the library when opening a stream for reading or writing.

Constructors

Info

Fields

frames :: Count

Number of frames in file

samplerate :: Int

Audio sample rate

channels :: Int

Number of channels

format :: Format

Header and sample format

sections :: Int

Number of sections

seekable :: Bool

True when stream is seekable (e.g. local files)

Instances

Eq Info

Show Info

Storable Info

data Format

Stream format specification, consisting of header, sample and endianness formats.

Not all combinations of header, sample and endianness formats are valid; valid combinations can be checked with the checkFormat function.

Constructors

Format

Fields

headerFormat :: HeaderFormat

sampleFormat :: SampleFormat

endianFormat :: EndianFormat

Instances

Eq Format

Show Format

data HeaderFormat

Header format.

Constructors

HeaderFormatNone

HeaderFormatWav

HeaderFormatAiff

HeaderFormatAu

HeaderFormatRaw

HeaderFormatPaf

HeaderFormatSvx

HeaderFormatNist

HeaderFormatVoc

HeaderFormatIrcam

HeaderFormatW64

HeaderFormatMat4

HeaderFormatMat5

HeaderFormatPvf

HeaderFormatXi

HeaderFormatHtk

HeaderFormatSds

HeaderFormatAvr

HeaderFormatWavex

HeaderFormatSd2

HeaderFormatFlac

HeaderFormatCaf

HeaderFormatWve

HeaderFormatOgg

HeaderFormatMpc2k

HeaderFormatRf64

Instances

Enum HeaderFormat

Eq HeaderFormat

Show HeaderFormat

data EndianFormat

Endianness.

Constructors

EndianFile

EndianLittle

EndianBig

EndianCpu

Instances

Enum EndianFormat

Eq EndianFormat

Show EndianFormat

data SampleFormat

Sample format.

Constructors

SampleFormatNone

SampleFormatPcmS8

SampleFormatPcm16

SampleFormatPcm24

SampleFormatPcm32

SampleFormatPcmU8

SampleFormatFloat

SampleFormatDouble

SampleFormatUlaw

SampleFormatAlaw

SampleFormatImaAdpcm

SampleFormatMsAdpcm

SampleFormatGsm610

SampleFormatVoxAdpcm

SampleFormatG72132

SampleFormatG72324

SampleFormatG72340

SampleFormatDwvw12

SampleFormatDwvw16

SampleFormatDwvw24

SampleFormatDwvwN

SampleFormatFormatDpcm8

SampleFormatFormatDpcm16

SampleFormatVorbis

Instances

Enum SampleFormat

Eq SampleFormat

Show SampleFormat

type Count = Int

Type for expressing sample counts.

Utils

toMC :: (Monad m, Source r1 e, Source r2 e, Target r2 e) => Int -> Array r1 DIM1 e -> m (Array r2 DIM2 e)

Converts vector signal to multi channel signal.

fromMC :: (Source r1 e, Source r2 e, Target r2 e, Monad m) => Array r1 DIM2 e -> m (Array r2 DIM1 e)

Converts multi channel signal to vector signal.

wav16 :: Info

16 bit MS wave, single channel, sampling rate = 48000.

wav32 :: Info

32 bit MS wave, single channel, sampling rate = 48000.