🚀 go-pugleaf

<ghislain.ruy@ieee.org> wrote in message news:3B48CDA3.CE2AAD36@ieee.org...
> Hello,

Hi Ghislane,

> does somebody know how to retrieve raw samples from a sound card in
> order to process them ?
> I had a look to winapi but it's quite cumbersome and I would prefer
> something like a linux driver (just read a file for example). Is there a
> dll to do the job ?

Unfortunately the driver model in Windows is significantly different to the
Linux one.  However, although the mmSystem API is a little complex it
doesn't take too long to work out.

Create a WAVEFORMATEX structure to describe the recording format you need
and pass it to waveInOpen() to open a wave input device.  Prepare two (or
more - two is a good starting number) buffers using waveInPrepareHeader(),
then add them to the record queue with waveInAddBuffer().  Start recording
with waveInStart().  Don't forget to allocate the memory for the buffers, as
the mmsystem won't do this for you.

Once that's all done you should get callbacks (or messages, or...) when each
buffer is filled.  Take the data out of the buffer and re-add the buffer to
the recording queue.  You might want to do this in a seperate thread to
abstract it all from your processing routines - use a memory stream or
something to store it in, then your processing routines just need to read
from the stream.

Once you are done recording, call waveInStop() to stop recording, wait for
the mmsystem to tell you it is done, then clean up: call
waveInUnprepareHeader() on all buffers prepared earlier, then waveInReset()
and finally waveInClose().

> Is it possible via the media player trough undocumented class members or
> so ?

I prefer to go straight to the mmsystem as it's about as low-level as you
can get without some knowledge of the actual sound drivers.  Of course you
could try using DirectSound... assuming it has a recording facility?  I
haven't touched DirectX yet, but then I haven't needed it.

> Thank you in advance for help.

Hope it helps.  Let me know if you get lost.

--
Corey Murtagh
The Electric Monk
"Quidquid latine dictum sit, altum viditur."