On Thu, 18 Oct 2018 03:13:33 +0700, JJ wrote:

And the number 4 in the MPEG4 container doesn't represent the version number
of the video/audio streams within the container. It's merely the version
number of the media container format. Each video/audio stream has its own
version which is encoding specific (or format specific).

However, AFAIK, an MPEG media (i.e. video+audio) container is for containing
MPEG video format only. i.e. it can not contain e.g. DVI, VP8, Windows Video
format. Audio format is more relaxed but AFAIK (correct me if I'm wrong),
there's still a limit on which audio formats are supported by the MPEG media
container.