MP4

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MP4 (MPEG-4 Part 14)
File extension : .mp4
MIME type : video / mp4
Developed by: MPEG , ISO
Type: Container format
Container for: Audio , video , text
Extended by: QuickTime .mov
Standard (s) : ISO / IEC 14496-14


MP4 is a video container format intended by MPEG for MPEG-4 content and standardized in ISO / IEC 14496-12 and -14 (MPEG-4 parts 12 and 14).

The MP4 file format is based on the Apple QuickTime file format. Both formats organize media data in hierarchical and sequential data units. These units are called “atoms” and their TYPE designators (moov, trak, mdia, minf, stbl etc.) are identical. You can record a variety of different media types and save them with structural information and their dependencies.

Multimedia content in the form of multiple audio and video tracks as well as subtitles, 2D and 3D graphics can be saved in MP4 files. This content can then be played back locally using suitable software or streamed over a network.

However, it is not usual to include all available formats in MP4 in order to be able to guarantee compatibility between different applications, although this would theoretically be possible through "private" labels (flags or atoms). The MPEG has therefore limited the container to the following formats:

  1. Video: MPEG-H Part 2 (HEVC / H.265 ) MPEG-4 Part 10 (AVC / H.264 ), MPEG-4 Part 2, MPEG-2 video and MPEG-1 video
  2. Audio: MPEG-4 Part 3, AAC , MP3 , MP2 , MP1
  3. Images: JPEG , PNG
  4. Graphics and text: BIFS (e.g. subtitles can be converted to this format)

The ATSC has also specified AC-3 for the mp4 container, but MPEG does not officially support this codec.

Alternative container formats are AVI , Matroska and Ogg Media .

file extension

The file extension of mp4 files has already created some confusion among users. The only file extension specified in the standard is .mp4; but since mp4 is a container format, it does not provide any information about the exact content of the file. That is why Apple is calling for additional file extensions that should name mp4 files more clearly. It says:

  • .m4v, .mp4v: - V ideo: only for video (MPEG-4 video streams)
  • .m4a: - A udio: only for audio ( MPEG-4 Part 3, AAC , or for the Apple Lossless codec )
  • .m4b: -Audio b ook: identifies audio books that can be bookmarked
  • .m4p: - P rotected: DRM -protected AAC
  • .m4r: - R ingtone: ringtones for iPhone

The endings . 3gp and .3g2 be used in mobile phones and are part of the 3GPP - Standard , the MPEG-4 is very similar, but can also use formats that are not common in .mp4 (for example, the. AMR speech codecs ).

supporting documents

  1. ↑ Network world knowledge: video formats. Retrieved January 17, 2019 .