fmtchunk
Fmtchunk is a chunk used in RIFF-based audio file formats, most notably the WAV format. It contains the essential format information that describes how the audio data in the file should be interpreted. The chunk has an ID of "fmt " (the four ASCII characters, including a trailing space) and a size field that indicates the length of the format data that follows.
In WAV files, the format data is defined by a structure that includes several fields. The format
The information in the fmt chunk is used by decoders to allocate buffers, interpret sample data, and