WAVEFORMAT

The WAVEFORMAT structure describes the format of waveform-audio data. Only format information common to all waveform-audio data formats is included in this structure. This structure has been superseded by the WAVEFORMATEX structure.

typedef struct { 
    WORD  wFormatTag; 
    WORD  nChannels; 
    DWORD nSamplesPerSec; 
    DWORD nAvgBytesPerSec; 
    WORD  nBlockAlign; 
} WAVEFORMAT; 
 

Members

wFormatTag

Format type. The following type is defined:

WAVE_FORMAT_PCM

Waveform-audio data is PCM.

nChannels

Number of channels in the waveform-audio data. Mono data uses one channel and stereo data uses two channels.

nSamplesPerSec

Sample rate, in samples per second.

nAvgBytesPerSec

Required average data transfer rate, in bytes per second. For example, 16-bit stereo at 44.1 kHz has an average data rate of 176,400 bytes per second (2 channels — 2 bytes per sample per channel — 44,100 samples per second).

nBlockAlign

Block alignment, in bytes. The block alignment is the minimum atomic unit of data. For PCM data, the block alignment is the number of bytes used by a single sample, including data for both channels if the data is stereo. For example, the block alignment for 16-bit stereo PCM is 4 bytes (2 channels — 2 bytes per sample).

Remarks

For formats that require additional information, this structure is included as a member in another structure along with the additional information.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in mmreg.h.

See Also

Waveform Audio Overview, Waveform Structures, WAVEFORMATEX