RIFFCHUNKS

RIFFCHUNKS refers to the chunk-based data container used by the Resource Interchange File Format (RIFF). RIFF is a generic multimedia container designed to store audio, video, and related data in a modular way. It was developed by Microsoft and IBM and has become a foundational structure for several common formats, notably WAV audio and AVI video. A RIFF file is organized as a sequence of chunks, each identified by a four-character ASCII ID and followed by a 32-bit little-endian size and then that many bytes of data. The top-level RIFF chunk itself includes a form type, such as WAVE or AVI, which indicates how the enclosed chunks should be interpreted.

The typical structure begins with the literal ASCII string RIFF, then a 4-byte size, then a 4-byte form type. After that, the file contains a series of subchunks. Each subchunk has its own 4-byte ID, a 4-byte size, and a payload of the indicated size. If a chunk’s size is odd, a padding byte is inserted to maintain even alignment for subsequent data. LIST chunks introduce nesting by containing subchunks after a 4-byte LIST type field, enabling hierarchical organization within the RIFF file.

Common chunks in WAV files include fmt , which describes audio format parameters such as codec, channels, sample rate, byte rate, block align, and bits per sample, and data, which holds the actual audio samples. Other chunks may carry metadata, timing cues, or non-audio information. RIFF’s chunk-based design supports extensibility by allowing new chunk IDs without breaking older parsers, contributing to its long-standing use in multimedia storage.