Wave file format

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The wave file format is a widely supported format for storing digital audio. A wave file uses the Resource Interchange File Format (RIFF) file structure and hence data is organized in chunks as described below. Each chunk contains information about its type and size and can easily be skipped by software that does not understand the specific chunk type.

The standard wave file format is organized as follows.



Byte sequence descriptionLength in bytesStarts at byteValue
chunk ID40x00The ASCII character string "RIFF"
size40x04The size of the wave file (number of bytes) less 8 (less the size of the "chunk ID" and the "size")
RIFF type ID40x08The ASCII character string "WAVE"
wave chunksvarious0x0CVarious chunks in the wave file as described below

Endianism

All information is stored with the least significant byte first (little-endian). For example, if the 4-byte value for the average bytes per second in the format chunk is 88,200 = 0x00015888, this information will be stored with the following byte sequence.

0x88 0x58 0x01 0x00

Word alignment

All information in a wave file must be word aligned (i.e., aligned at every two bytes). If a chunk has an odd number of bytes, then it will be padded with a zero byte, although this byte will not be counted in the size of the chunk.

Wave chunks

A wave file would include at least the following chunks.

Format chunk
Data chunk

Other chunks that may exist in a wave file include the following.

Silent chunk
Wave list chunk
Fact chunk
Cue chunk
Playlist chunk
List chunk
Sample chunk
Instrument chunk

Other RIFF chunks

Since the RIFF format is used for other types of files, such as AVI files, a RIFF file can contain types of chunks that are not relevant to the wave file format. For example, the junk and pad chunks are used to add random data to the file to, perhaps, align the file chunks on a 2K boundary. A software application does not have to recognize or use all chunk types and may ignore certain chunks.



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Copyright 2006 by Kaliopa Publishing, LLC