Buffer data can be read and written using wxMediaStreamIn and wxMediaStreamOut objects.
Buffer information can only be read from or written to one stream at a time. To write one or more buffers to a stream, first call the function wxWriteMediaGlobalHeader to write initialization data into an output stream. When all buffers are written to the stream, call wxWriteMediaGlobalFooter. Similarly, reading buffers from a stream is initialized with wxReadMediaGlobalHeader and finalized with wxReadMediaGlobalFooter.
The media file data format can be embedded within another file, and it can be extended with new kinds of data. The media file format can be extended in two ways: with snip- or content-specific data, and with buffer-specific global data. These are descibed in the remainder of this section.