• C

Low level MM in win32

In linux you can play or record sound (from sound card) just with opening file "dev/dsp" and change settings with ioctl. Are there similar functions in win32 API? Please any short working example.
abmoAsked:
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The_RavenConnect With a Mentor Commented:
Are you looking for a double buffering system, something like this ? (This is something I wrote using Imprise C++ Builder)

VOID StartRecord(void)
{
   MMRESULT rc;
   int      i;
   MMTIME   mmtime;

// prepare buffer blocks and add to input queue
//.............................................

for (i = 0; i < MAX_BUFFERS; i++)      {                                                              
  rc = waveInPrepareHeader(hwi, wh[i], sizeof(WAVEHDR));    
  // add buffers to the input queue                            
  if (rc == MMSYSERR_NOERROR)
    rc = waveInAddBuffer(hwi, wh[i], sizeof(WAVEHDR));
   if (rc != MMSYSERR_NOERROR
   {waveInGetErrorText(rc, msg, MSG_LEN),                        
    MessageBox(Application->Handle, msg, NULL, MB_OK);
    StopRecord();  // free allocated memory
    return; }
                                    }
// start recording                                              
//................                                              
                                                                   rc = waveInStart(hwi);
    mmtime.wType = TIME_SAMPLES;
    rc = waveInGetPosition(hwi, &mmtime, sizeof(MMTIME));
    if (rc != MMSYSERR_NOERROR)
    {
      waveInGetErrorText(rc, msg, MSG_LEN),
      MessageBox(Application->Handle, msg, NULL, MB_OK);
    }                                          
}
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Tommy HuiEngineerCommented:
Yes, there is something similar.

You should use mixerSetControlDetails() and mixerGetControlDetails(). Also look into mixerGetLineControls().
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abmoAuthor Commented:
Sorry for rejecting, but can you insert some working example which can play (or record) something?  
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The_RavenCommented:
Play Sound...

#define MSG_SIZE 1024
char Msg[MSG_SIZE+1];

mciSendString("open test.wav type waveaudio alias mywave",Msg, MSG_SIZE, (HANDLE)hWnd);
mciSendString("set mywave time format samples",Msg, MSG_SIZE, (HANDLE)hWnd);
mciSendString("play mywave from 1 waid",Msg, MSG_SIZE, (HANDLE)hWnd);
mciSendString("close mywave",Msg, MSG_SIZE, (HANDLE)hWnd);

------------------------------------------------------------
Record Sound...

mciSendString("open new type waveaudio alias mywave",Msg, MSG_SIZE, (HANDLE)hWnd);
mciSendString("record mywave",Msg, MSG_SIZE, (HANDLE)hWnd);

// Do something here until record is terminated

mciSendString("stop mywave",Msg, MSG_SIZE, (HANDLE)hWnd);
mciSendString("save mywave tst.wav",Msg, MSG_SIZE, (HANDLE)hWnd);
mciSendString("close mywave",Msg, MSG_SIZE, (HANDLE)hWnd);

That is the easyest way to do it.

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abmoAuthor Commented:
Ehm, sorry, that is for MCI and wave file. But isn´t there any possibility to read and write sound as a file (or something similar)?
Exactly I need to display "volume" in peaks of dB of incoming sound (so I need to "read" samples to memory), analyze it (at a sampling rate of 32000Hz) in real time, and then record (only good :-) samples) or do something. And I think there should be some low level MM functions to do that, but I didn´t found it yet...
Can you help me?
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core123Commented:
Look for some documentation on the waveIn* functions such as waveInOpen(), they'll enable you to record sound on the windows system.  Hope you can find some :)
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abmoAuthor Commented:
YES YES YES, that it is, thank you all. It is a bit more complicated, than I thinked about. The_Raven just can you add some note (example) on how to get "hwi" handler?
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