WAVEFORMAT

The WAVEFORMAT structure describes the format of waveform data. Only format information common to all waveform data formats is included in this structure. For formats that require additional information, this structure is included as a field in another data structure along with the additional information.

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

Fields

The WAVEFORMAT structure has the following fields:

wFormatTag

Specifies the format type. Currently defined format types are as follows:

WAVE_FORMAT_PCM

Waveform data is PCM.

nChannels

Specifies the number of channels in the waveform data. Mono data uses 1 channel and stereo data uses 2 channels.

nSamplesPerSec

Specifies the sample rate in samples per second.

nAvgBytesPerSec

Specifies the required average data transfer rate in bytes per second.

nBlockAlign

Specifies the block alignment in bytes. The block alignment is the minimum atomic unit of data.

Comments

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).

See Also

PCMWAVEFORMAT