MPEG-4 Systems File Format (MP4)

1. What is the purpose of the MP4 file format?
2. MPEG-4 is based on QuickTime?
3. What is the Intermedia Format, and how does it relate to MP4?
4. Will MP4 define an on-the-wire streaming protocol?

1. What is the purpose of the MP4 file format?

The MP4 file format contains the media information of an MPEG-4 presentation in a flexible, extensible format which facilitates interchange, management, editing, streaming and presentation of the media. This presentation may be local to the system containing the presentation or via other stream delivery mechanism (a TransMux) while the file format is independent of any particular TransMux.

2. MPEG-4 is based on QuickTime?

No, QuickTime was taken as a starting point only for the file format. Other relevant software products and their features have influenced the file format as well.

3. What is the Intermedia Format, and how does it relate to MP4?

They are one and the same. Intermedia is a term created to describe a format intended for interchange, local playback, editing and streaming.

4. Will MP4 define an on-the-wire streaming protocol?

No. MP4 is being called a streamable format as opposed to a streaming format.The file format contains structures to facilitate streaming of the content in standard network protocols rather than defining a new format of its own. So MP4 is never carried over the wire; the contents of an MP4 file are delivered via standard TransMuxes.