[Haskell-cafe] Problem with OpenAL

[George Giorgidze]

I am also getting the same output: "0" indicates the number of processed
buffers, and "1" the number of queued buffers. It means that the small
buffer which is queued for playback never gets processed completely.

The first argument of playOpenAL functions is a sampling rate of an audio
playback, so you might wont to try "playOpenAL 44100".

Currently in my application for audio IO, I am using my own binding to
portaudio (C library).
As OpenAL is included with GHC source release, I thought it would be nice to
have support for OpenAL as well.

Can anyone report success with OpenAL and post some code examples?

George

P.S. I am using
GHC 6.8.2 compiled from source on ubuntu linux
OpenAL binding version OpenAL-1.3.1.1
OpenAL version libopenal 1.0.0.8

On Sat, Mar 22, 2008 at 4:13 PM, Antoine Latter <aslatter at gmail.com> wrote:

> For those of you following along, you'll need:
>
> > import qualified Sound.OpenAL as AL
> > import Data.Maybe
> > import Foreign.C.Types
> > import Control.Monad
> > import Control.Concurrent
> > import Foreign.Storable
> > import Foreign.Marshal.Alloc
>
> when I run "playOpenAL 440" I get no sound, and the following is
> repeatedly printed on the console:
>
> waiting
> 0
> 1
> waiting
> 0
> 1
> waiting
> 0
> 1
> waiting
> 0
> 1
>
> What do you think should be happening?
>
> -Antoine
>
> 2008/3/21 George Giorgidze <ggg at cs.nott.ac.uk>:
> > I tried OpenAL binding (the one which is on the Hackage), but with no
> luck.
> >
> > I can not hear anything from speakers and also according to generated
> output
> > on console it seems that "AL.play" never completes playback of a buffer
> as
> > buffer remains registered as "unprocessed" in OpenAL context.
> >  Here is the piece of code. I am not getting any error messages from
> OpenAL
> > library functions.
> >
> > playOpenAL :: Int -> IO ()
> > playOpenAL sr  = do
> >    mDevice <- AL.openDevice Nothing
> >   when (isNothing mDevice) $ error "opening OpenAL device"
> >    let device = fromJust mDevice
> >
> >   mContext <- AL.createContext device [
> >        AL.Frequency (fromIntegral sr)
> >     , AL.Refresh (fromIntegral sr)
> >      ]
> >   when (isNothing mContext) $ error "creating OpenAL context"
> >    let context = fromJust mContext
> >   AL.currentContext AL.$= (Just context)
> >
> >
> >   let sampleNumber = 256
> >        bufSize = sampleNumber * (sizeOf (undefined :: CShort))
> >   buf2 <- mallocBytes bufSize
> >
> > -- here I am filling buf2 with noise ....
> >
> >    [source] <- AL.genObjectNames 1
> >   [buffer] <- AL.genObjectNames 1
> >
> >   let region = AL.MemoryRegion buf2 (fromIntegral bufSize)
> >   AL.bufferData buffer AL.$= (AL.BufferData region AL.Mono16(fromIntegral
> > sr))
> >
> >
> >   AL.queueBuffers source [buffer]
> >    AL.loopingMode source AL.$= AL.OneShot
> >
> >    let waitForSource = do
> >         putStrLn "waiting"
> >          s <- AL.get (AL.buffersProcessed source)
> >          putStrLn $ show s
> >         s <- AL.get (AL.buffersQueued source)
> >          putStrLn $ show s
> >         state <- AL.get (AL.sourceState source)
> >          case state of
> >           AL.Playing -> do
> >              threadDelay 1024
> >              waitForSource
> >           _ -> return ()
> >
> >   putStrLn "Start Playing ... "
> >   AL.play [source]
> >    waitForSource
> >
> >
> >   AL.currentContext AL.$= Nothing
> >    AL.destroyContext context
> >   b <- AL.closeDevice device
> >    when (not b) $ error "closing device"
> >
> >
> > Is this library still maintained?
> >
> > Best, George
> >
> > _______________________________________________
> >  Haskell-Cafe mailing list
> >  Haskell-Cafe at haskell.org
> >  http://www.haskell.org/mailman/listinfo/haskell-cafe
> >
> >
>



-- 
George Giorgidze
http://www.cs.nott.ac.uk/~ggg/ <http://www.cs.nott.ac.uk/%7Eggg/>
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