The capGetAudioFormatSize macro obtains the size of the audio format. You can use this macro or explicitly call the WM_CAP_GET_AUDIOFORMAT message.
DWORD capGetAudioFormatSize(
hwnd
);
Returns the size, in bytes, of the audio format.
Because compressed audio formats vary in size requirements applications must first retrieve the size, then allocate memory, and finally request the audio format data.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in vfw.h.
Video Capture Overview, Video Capture Macros, WM_CAP_GET_AUDIOFORMAT