What has mp4 got against ac3?

[berrinam]

Not meaning to start any arguments about which container is best, but I was just wondering what the reasoning behind mp4 not supporting ac3 as an audio stream was

[lazyn00b]

Hi berrinam, I totally agree with you, but you better get ready for some pretty srtrong opinions from mp4 "purists" against what you are suggesting - LOL! With all the other ad-hoc mods done to the mp4 - mp3, ogg vorbis, Nero subs, etc. - I really don't see the big problem with adding ac3 as a "private stream" or whatever.

[Sergei_Esenin]

Lack of AC3 support in MP4 is why I use MKV. The idea of having to re-encode an original AC3 stream to AAC, saving relatively very little space in the process, is anathema to me in the age of cheap DVD+R and big hard drives. So, I like to keep the original AC3, and Matroska is perfect for this. What's better about that limited and "crippled" MP4 anyway? :eek:

Uh-oh, I'd better go hide. :D

But seriously, I do like to use MP4 for my analogue caps, because it's aesthetically pleasing to use a unified platform for video, audio, and container. But it doesn't meet my needs for DVD rips due to its limitations; MKV is superior in that respect, and that's why I use it any time I want to use a codec not native to MP4.

[berrinam]

I am aware of the facts that (a) avc and ac3 (and about anything else, too) can be put in matroska and (b) that ac3 could theoretically be put in mp4 through private streams. What I was asking was why did the Motion Pictures Experts Group decide to exclude a popular audio format like AC-3 from their file format specifications? Is it because they didn't invent it?

[Doom9]

I guess licensing may have a lot to do with it. Though chances of standalones supporting MP4 are much higher (consider it a given for many future players because Nero is pouring money into their certification program and getting more players out.. and anything that has the NeroDigital logo can handle MP4) than MKV. Still.. if you play your backups on a PC that point is moot.

[bond]

ac3 can be placed in mp4 there is just no tool to place ac3 in mp4...

mpeg doesnt define how to place ac3 into mp4 as it also doesnt define how to place ac3 in .mpg

its makes no sense to place ac3 in mp4

[berrinam]

ac3 can be placed in mp4 there is just no tool to place ac3 in mp4...

Do you refer to private streams?

its makes no sense to place ac3 in mp4
Why not? Is this because ac3 is not an MPEG standard?

[bond]

Do you refer to private streams?
yes

Why not? Is this because ac3 is not an MPEG standard? because the point of using mp4 is interoperability, which means using aac audio + asp or avc video

when punching any codec you want in it that point gets lost
if you want an all codec container use matroska

[berrinam]

ok, I'm with you now