[Haskell-cafe] FFI woes!

Sebastian Sylvan sebastian.sylvan at gmail.com
Thu Dec 16 10:25:55 EST 2004

On Thu, 16 Dec 2004 12:35:55 +0000, Keean Schupke
<k.schupke at imperial.ac.uk> wrote:
> Okay, you want to poll to see if the sound is still playing... This is
> not very
> easy to do...
> You really want to use the low-buffer callback from the soundcard
> driver to load the next sample into the buffer using DMA. (IE you
> can pass a function to the driver to call when you sample has been
> copied completely to the sound-cards memory). This is the way to
> do it...
>     play_then_free = do
>         set_callback (free_sample my_sample)
>         play_sample my_sample
> You can see that this provides the interface you want to the user (IE
> samples are freed once they are finished with)...
>     Keean.

This is exactly how I do it for the Stream sound type, since this type
of sound supplies a callback for when it reaches the end. The sound
sample does not, though.
(stream is streamed from disk, sound sample is loaded into memory).


Sebastian Sylvan
UIN: 44640862

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