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nOZ
20th August 2007, 05:57
Sometimes I view a video file's properties with VLC or MPC, and it will list the vcodec as xvid/divx/h264/avc1/mpeg/theo or whatever. But, for some of my files it will report the vcodec as mp4v. Isn't mpeg4 just an umbrella term that encompasses numerous different A/V standards? So, what exactly does it mean when the player says the vcodec is mp4v?

edit: Sorry, all instances of "mp4" should have been "mp4v".

Stingrey
20th August 2007, 08:14
MPEG 4 is much more than you think.
It's a Container, VCodec, ACodec, ...
It consists of 23 different parts.
For a short overview look here:
http://en.wikipedia.org/wiki/MPEG-4

CWR03
20th August 2007, 08:32
MPEG-4 is not the same thing as MP4:

http://en.wikipedia.org/wiki/Mp4

MPEG-4 is, as you said, an umbrella term for several video codecs, while .mp4 is a container standard.

Stingrey
20th August 2007, 10:10
I know that's not the same.
But MP4 is like you said a container format, not a video codec.
So because the program says MP4 as video codec, I refered to MPEG 4.
Most likely it is a ASP or AVC codec in your file.

SeeMoreDigital
20th August 2007, 10:38
How about referring to Bond's excellent information?

http://forum.doom9.org/showthread.php?t=62723

nOZ
20th August 2007, 20:31
I know mp4 is also a container format, but I was referring only to the streams inside the container. However, it was my fault because what I meant was mp4v. I've edited my original post to correct this.

Anyway, thanks for everyone's help. I came across this wiki article: http://en.wikipedia.org/wiki/MPEG-4_Part_2 in which the the fourth sentence says, "several popular codecs including DivX, Xvid and Nero Digital are implementations of this standard". I think I get it now, but correct me if I'm still wrong.

The one word that made it clear to me was "implementation", which tells me that these other codecs (xvid, divx, nero, etc) isn't exactly the same as mp4v, but are based off of it. So when the properties of a file lists the vcodec as mp4v or mpeg4_video then that IS the vcodec, it's just not one of the derivatives.

I think my confusion came from a lot of articles that would list a bunch of codecs, all except mp4v itself, which naturally lead me to believe that mp4v is simply a label for all these OTHER codecs. This is why I wondered, "ok my player says mp4v is the vcodec, but is it xvid or divx or something else?"

SeeMoreDigital
20th August 2007, 20:36
Sounds like you need to look at the following links too: -

http://forum.doom9.org/showthread.php?t=73022

http://forum.doom9.org/showthread.php?t=96059