<p>MP4 has not really an official meaning, but it adds a lot to the MPEG-confusion. MP4 refers to MPEG-4 which is a huge collection of video-related standards that has been growing for more than 20 years.</p>
<p><strong>MPEG-4 part 14 container</strong>: takes an .mp4 file extension, therefore often just called MP4, if it contains audio, it can also have the .m4a extension, for video .m4v, and others (.m4p, .m4b, .m4r). the container format is a derivative of Apple QuickTime's container format (.mov).</p>
<p><strong>MPEG-4 Part 2 video codec</strong>: Most often just called <em>MPEG-4</em>, sometimes it also takes the name of the encoder software: Xvid, DivX... Became the first de facto standard for web video.</p>
<p><strong>MPEG-4 Part 10 video codec</strong>: also called <em>MPEG-4 AVC</em> and <em>(ITU-T) H.264</em>, and by the name of it's most popular encoder software: <em>x264</em>. De facto standard video codec today: video conferencing, smartphone videography, Web, Blu-Ray, TV, camcorders. Almost all video capable devices ship today with H.264/AVC hardware codecs by default besides newer but still less common codecs like VP9, HEVC or AV1. The successor for H.264/AVC has been coming since 2013, but just for fun they decided not to call it MPEG-4, but <strong>MPEG-H Part 2</strong> also known as <em>ITU-T H.265</em> or <em>High Efficiency Video Coding (HEVC)</em>.</p>
<p><strong>AAC</strong> (Advanced Audio Coding) is often called <em>MPEG-4 Audio</em>. It is probably the most prominent amongst the many codecs standardised in <em>MPEG-4 Part 3</em>. It often uses the file extension .mp4 or .m4a</p>
<p>I'm not even going to start about <a href="http://en.wikipedia.org/wiki/Moving_Picture_Experts_Group#Standards" rel="nofollow noreferrer">all the other MPEGs</a> :-)</p>
<h2>TL;DR</h2>
<p>MP4 could mean a video codec, a file that contains video and/or audio or even something else. It's not a clear term.</p>

CC BY-SA 4.0
2014-02-15T21:56:55.813Z
2021-03-09T16:48:18.410Z
2021-03-09T16:48:18.410Z
Duvrai
<p><a href="http://en.wikipedia.org/wiki/MPEG-4_Part_14" rel="nofollow">MP4</a> is a container, not a video format.  MP4 generally contains a variant of MPEG for the video, such as h.264 or generic MPEG-4.  Sometimes they may contain an MPEG-2 or MPEG-1 stream, though that is pretty uncommon.</p>

CC BY-SA 3.0
2014-01-16T20:24:18.713Z
So MP4 and MKV are only containers? How can MKV contain a MP4 then? This is where I get confused. MP4 can contain AVC, so can MKV. Look [this](http://www.overclock.net/t/1257650/which-hd-video-format-has-the-best-quality-mkv-or-mp4-or-other) thread.
evil
CC BY-SA 3.0
2014-01-16T20:47:04.890Z
@evil - an MKV can not contain an MP4, it can contain an h.264 stream or an MPEG-4 stream.  People often confuse MP4 with MPEG-4, one is a container format, the other is a video stream format.  The thread you linked is incorrect in saying that an MKV can contain an MP4 as far as I know unless it actually can contain other containers.
AJ Henderson
CC BY-SA 3.0
2014-01-16T21:57:43.653Z
MPEG-4 and h.264 is the same thing though? h.264=AVC=MPEG-4 Part 10. It's really confusing.
evil
CC BY-SA 3.0
2014-01-17T00:03:16.307Z
h.264 if a portion of the MPEG standard (part 10 as it were), there is also the more general part 2.  MP4 is actually also part of the MPEG standard (part 14).  MPEG is a broad spectrum developed by the MPEG group and covers more than just one thing.
AJ Henderson
CC BY-SA 3.0
2014-01-16T20:05:43.473Z
2014-01-16T20:05:43.473Z
AJ Henderson
<p>Please explain, so confusing. I get that <strong>AVC</strong> is a video format, <strong>MKV</strong> is a container (that can contain mp4 video, FLAC audio etc.), but what is <strong>mp4</strong> then?</p>

<mp4>
mp4 - Codec or Container
evil
# mp4 - Codec or Container

(Asked by: username_0 on 2014-01-16)

Please explain, so confusing. I get that **AVC** is a video format, **MKV** is a container (that can contain mp4 video, FLAC audio etc.), but what is **mp4** then?

**Tags:** mp4


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## 2 answers

### Answer by username_1 on 2014-02-15. Score: 6

MP4 has not really an official meaning, but it adds a lot to the MPEG-confusion. MP4 refers to MPEG-4 which is a huge collection of video-related standards that has been growing for more than 20 years.

**MPEG-4 part 14 container**: takes an .mp4 file extension, therefore often just called MP4, if it contains audio, it can also have the .m4a extension, for video .m4v, and others (.m4p, .m4b, .m4r). the container format is a derivative of Apple QuickTime's container format (.mov).

**MPEG-4 Part 2 video codec**: Most often just called *MPEG-4*, sometimes it also takes the name of the encoder software: Xvid, DivX... Became the first de facto standard for web video.

**MPEG-4 Part 10 video codec**: also called *MPEG-4 AVC* and *(ITU-T) H.264*, and by the name of it's most popular encoder software: *x264*. De facto standard video codec today: video conferencing, smartphone videography, Web, Blu-Ray, TV, camcorders. Almost all video capable devices ship today with H.264/AVC hardware codecs by default besides newer but still less common codecs like VP9, HEVC or AV1. The successor for H.264/AVC has been coming since 2013, but just for fun they decided not to call it MPEG-4, but **MPEG-H Part 2** also known as *ITU-T H.265* or *High Efficiency Video Coding (HEVC)*.

**AAC** (Advanced Audio Coding) is often called *MPEG-4 Audio*. It is probably the most prominent amongst the many codecs standardised in *MPEG-4 Part 3*. It often uses the file extension .mp4 or .m4a

I'm not even going to start about [all the other MPEGs](http://en.wikipedia.org/wiki/Moving_Picture_Experts_Group#Standards) :-)

## TL;DR

MP4 could mean a video codec, a file that contains video and/or audio or even something else. It's not a clear term.


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### Answer by username_2 on 2014-01-16. Score: 1

[MP4](http://en.wikipedia.org/wiki/MPEG-4_Part_14) is a container, not a video format. MP4 generally contains a variant of MPEG for the video, such as h.264 or generic MPEG-4. Sometimes they may contain an MPEG-2 or MPEG-1 stream, though that is pretty uncommon.

> **Comments:**
> **username_0**: So MP4 and MKV are only containers? How can MKV contain a MP4 then? This is where I get confused. MP4 can contain AVC, so can MKV. Look [this](http://www.overclock.net/t/1257650/which-hd-video-format-has-the-best-quality-mkv-or-mp4-or-other) thread.  
> **username_2**: @username_0 - an MKV can not contain an MP4, it can contain an h.264 stream or an MPEG-4 stream.  People often confuse MP4 with MPEG-4, one is a container format, the other is a video stream format.  The thread you linked is incorrect in saying that an MKV can contain an MP4 as far as I know unless it actually can contain other containers.  
> **username_0**: MPEG-4 and h.264 is the same thing though? h.264=AVC=MPEG-4 Part 10. It's really confusing.  
> **username_2**: h.264 if a portion of the MPEG standard (part 10 as it were), there is also the more general part 2.  MP4 is actually also part of the MPEG standard (part 14).  MPEG is a broad spectrum developed by the MPEG group and covers more than just one thing.  

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