Sound data structures

At the request of Don Stuart, here is some information about the formats supported by different sound libraries.

In-memory data formats

In-memory sound formats are fairly diverse.

Reading and writing sound files

Library	Sound file format
HCodecs	(Audible a) => DiffUArray Int a
hsndfile	MArray with Float and Double
HSoundFile	[[Double]]
ALUT	OpenAL.AL.Buffer
WAVE	[[Int32]]
Sox	Lists, Storable Vector, whatever you have a hPut and hGetContents function for.
libsox	Storable Vector
riff	Data.ByteString.Lazy

Playing sounds

Library	Sound file format
OpenAL	Ptr UInt8, Ptr Int16, 1-N channels
SDL-mixer	ForeignPtr ChunkStruct, ForeignPtr MusicStruct

Sound processing libraries

Library	Sound file format
dsp	Array a, [a]
synthesizer	[a], StorableVector.Lazy a, (StateT s Maybe a, s) (like stream-fusion)
jack	Operates via mapping functions mainMono :: (CFloat -> IO CFloat) -> IO () mainStereo :: ((CFloat, CFloat) -> IO (CFloat, CFloat)) -> IO (), StorableArray
alsa-pcm	(SampleFrame a) => Ptr a
Hommage	[a]

MIDI-based

Library	Sound file format
HCodecs	Reads and writes MIDI files
midi	Reads and writes MIDI files
alsa-midi	Uses midi library
Haskore	Uses midi library
alsa-seq	Custom midi structures
YampaSynth	Stand-alone program

Special-purpose APIs only (FFIs, etc.)

Library	Sound file format
hCsound	CsoundPtr
HasSound / Haskore	OrcExp
hsc3	UGen

No public sound-buffer API

Library	Sound file format
hbeat	The relevant source files are missing!
hogg	Very low-level API for Ogg internals only
libmpd	No sound buffer API
sonic-visualizer	No sound buffer API
truelevel	Stand-alone program (uses WAVE)
wavconvert	Stand-alone program