Using the PCMWAVEFORMAT Structure

For PCM audio data, use the PCMWAVEFORMAT329HC5C structure to specify the data format. The following example shows how to set up a PCMWAVEFORMAT structure for 11.025 kilohertz (kHz) 8-bit mono and for 44.1 kHz 16-bit stereo. After setting up PCMWAVEFORMAT, the example calls the IsFormatSupported function to verify that the PCM waveform output device supports the format. The source code for IsFormatSupported is shown in an example in Determining Nonstandard Format Support9TZNQJ.

UINT wReturn;

PCMWAVEFORMAT pcmWaveFormat;

// Set up PCMWAVEFORMAT for 11 kHz 8-bit mono.

pcmWaveFormat.wf.wFormatTag = WAVE_FORMAT_PCM;

pcmWaveFormat.wf.nChannels = 1;

pcmWaveFormat.wf.nSamplesPerSec = 11025L;

pcmWaveFormat.wf.nAvgBytesPerSec = 11025L;

pcmWaveFormat.wf.nBlockAlign = 1;

pcmWaveFormat.wBitsPerSample = 8;

// See if format is supported by any device in system.

wReturn = IsFormatSupported(&pcmWaveFormat, WAVE_MAPPER);

// Report results.

if (wReturn == 0)

     MessageBox(hMainWnd, "11 kHz 8-bit mono is supported.",

       "", MB_ICONINFORMATION);

else if (wReturn == WAVERR_BADFORMAT)

     MessageBox(hMainWnd, "11 kHz 8-bit mono NOT supported.",

       "", MB_ICONINFORMATION);

else

     MessageBox(hMainWnd, "Error opening waveform device.",

       "Error", MB_ICONEXCLAMATION);

// Set up PCMWAVEFORMAT for 44.1 kHz 16-bit stereo.

pcmWaveFormat.wf.wFormatTag = WAVE_FORMAT_PCM;

pcmWaveFormat.wf.nChannels = 2;

pcmWaveFormat.wf.nSamplesPerSec = 44100L;

pcmWaveFormat.wf.nAvgBytesPerSec = 176400L;

pcmWaveFormat.wf.nBlockAlign = 4;

pcmWaveFormat.wBitsPerSample = 32;

// See if format is supported by any device in the system.

wReturn = IsFormatSupported(&pcmWaveFormat, WAVE_MAPPER);

/ Report results.

if (wReturn == 0)

    MessageBox(hMainWnd, "44.1 kHz 16-bit stereo is supported.",

      "", MB_ICONINFORMATION);

else if (wReturn == WAVERR_BADFORMAT)

    MessageBox(hMainWnd, "44.1 kHz 16-bit stereo NOT supported.",

      "", MB_ICONINFORMATION);

else

    MessageBox(hMainWnd, "Error opening waveform device.",

      "Error", MB_ICONEXCLAMATION);