The ACMFORMAT type exposes the following members.
Extra format information is appended to the end of the WAVEFORMATEX structure in this array. This information can be used by non-PCM formats to store extra attributes for the wFormatTag. If no extra information is required by the wFormatTag, this member should be set to zero. For WAVE_FORMAT_PCM formats (and only WAVE_FORMAT_PCM formats), this member is ignored.
The WAVEFORMATEX structure that specifies the basic format.