Re: [Haskell-cafe] Problem with OpenAL

22 Mar 2008

      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 :
...
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
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Re: [Haskell-cafe] Problem with OpenAL

Antoine Latter