Audio Format

You can retrieve the current capture format for audio data or the size of the audio format structure by sending the WM_CAP_GET_AUDIOFORMAT message (or the capGetAudioFormat and capGetAudioFormatSize macros) to a capture window. The default audio capture format is mono, 8-bit, 11 kHz PCM (Pulse Code Modulation). When you retrieve the format by using WM_CAP_GET_AUDIOFORMAT, always use the WAVEFORMATEX structure.

You can set the capture format for audio data by sending the WM_CAP_SET_AUDIOFORMAT message (or the capSetAudioFormat macro) to a capture window. When setting the audio format, you can pass a pointer to a WAVEFORMAT, WAVEFORMATEX, or PCMWAVEFORMAT structure, depending on the specified audio format.