A digital multimedia container format most commonly used to store video and audio, but which can also be used to store other data such as subtitles and still images.

MP4 is a shortening of MPEG-4 Part 14, a digital multimedia container format most commonly used to store video and audio, but which can also be used to store other data such as subtitles and still images. The term MPEG stands for the Moving Picture Experts Group.

While MP4 is a container format, it is commonly confused with MPEG4 part 2 - MPEG-Visual which is a video codec, often used inside MP4 files, along with a later and more ubiquitous codec (MPEG-4 Part 10, Advanced Video Coding or MPEG-4 AVC) .

While h.264 is very common in MP4 video files, MP4 files can contain other codecs and different media:

  • Video: MPEG-4 Part 10 (H.264) and MPEG-4 Part 2
  • Other compression formats are less used: MPEG-2 and MPEG-1
  • Audio: Advanced Audio Coding, also MPEG-4 Part 3 audio objects, such as Audio Lossless Coding (ALS), Scalable Lossless Coding (SLS), MP3, MPEG-1 Audio Layer II(MP2), MPEG-1 Audio Layer I (MP1), CELP, HVXC (speech), TwinVQ, Text To Speech Interface (TTSI) and Structured Audio Orchestra Language (SAOL) and Apple Lossless
  • Subtitles: MPEG-4 Timed Text (also known as 3GPP Timed Text). Nero Digital uses DVD Video subtitles in MP4 files