MP4 is a new container format, a container format allows you to combine different multimedia streams into one single file. Multimedia containers are for example the well known AVI, MPEG , Matroska, OGM. MP4 is the global file extension for the official container format defined in the MPEG-4 standard. MP4 is streamable and supports all kinds of multimedia content, multiple audio-, video-, subtitlestreams, pictures, variable-framerates, -bitrates, -samplerates...) and advanced content like 2D and 3D animated graphics, user interactivity, DVD-like menus.

A codec that the psp uses for audio and video.

MPEG-4 Part 14 or *.mp4, is a file format (a so called container) specified as a part of the ISO/IEC MPEG-4 international standard. MPEG-4 is designed to deliver DVD quality video (MPEG-2) at lower bitrates rates and smaller file sizes. MPEG-4 is based on the Advanced Audio Coding (AAC) codec, providing much more efficient compression than MP3 with a quality similiar to that of uncompressed CD audio.

A compressed multimedia file type used particularly for moving picture and music (audio) files.

(also known as mpeg-4, .mp4) -- is the file format used to store media types defined by the ISO/IEC Moving Picture Experts Group. It is the format used by Apple® for video playback on the iPod Video Player. It is also the format used by the Sony PSP and other MP3 video players.

An extension for MPEG-4 video files.

Short for Moving Picture Experts Group, also known as MPEG-4.The term refers to the standard for audio and video streaming and complex media manipulation. Analogous to MP3 technology for audio, MP4 is the technology used for the mobile transmission and storage of images and video clips. See also MP3.

A lossy audio compress format, also known as AAC.

A multimedia “container” defined in the MPEG-4 standard (file extension: .mp4) that can combine media in different formats into one file. MP4s can handle multiple audio and video streams, variable bit/stream/sample rates, and even 3D graphics and interactive features.