The PXGF format is loosely based on the Microsoft RIFF file format. The RIFF format is based on the concept of a chunk. Chunks are blocks that contain specific application defined data. In the RIFF format the complete file is a single RIFF chunk. RIFF chunks and LIST chunks are currently the only two types of chunks that may contain sub-chunks. All the remaining chunks in the file are children of the global RIFF chunk.
The RIFF format is unsuitable for our purposes for two primary reasons:
Ø The global RIFF chunk is limited in size to 4GB, thereby effectively restricting the file size to 4GB.
Ø The RIFF format is unsuitable for streaming applications as one need to read the whole file sequentially to be able to parse it. There is no synchronization mechanism available.
For these reasons a new file and streaming format was proposed and developed, namely the PXGF format.