PDA

View Full Version : AC3 audio in an .MP4 container

SeeMoreDigital
17th March 2004, 21:06
Is it possible. Would it work?

I'm just curious!

Cheers
bond
17th March 2004, 21:21
theoretically its possible to add any stream to mp4 with a private track id (that way its already practically (!) possible to put vorbis and vobsub into mp4)
but you have to notice that no player will handle these private track ids if not explicitely specified to do so

so all in all ac3 in .mp4 is a baaad idea, also from the point of view that you can have the same multichannel quality with aac at half (or less) the bitrate (which is officially allowed in .mp4) so why waste bitrate with ac3 :D
SeeMoreDigital
17th March 2004, 21:36
Hmm!

Unfortunatly, my Xcard (or anybody elses Xcard for that matter) can't playback 6Ch AAC audio :(

Dispite the fact that AC3 in .MP4 is non spec compliant I would like to see if it would work!

If the Xcard is anything to go by. It can already play non spec compliant .MP4 content anyway.

Cheers
bond
17th March 2004, 21:42
ac3 in mp4 with private track id is not a "not spec complaint" .mp4 file!
but i am sure that your xcard will not handle such a file, so its a no go for this purpose
SeeMoreDigital
17th March 2004, 22:00
Well my next question is... can you genetate one so I can try?

Go on. You know you want too! :D

Cheers
bond
17th March 2004, 22:04
no there is no tool which can do this (as i said only vorbis and vobsub can be added this way atm)
SeeMoreDigital
17th March 2004, 22:09
I've not tried either in .MP4

It might be good to include some examples on my web site!

Cheers
KpeX
17th March 2004, 22:14
Why do you need to use the Xcard? Just use the TV-out and Audio-out with any good player (MPC/VLC/Zoomplayer/ etc.)
bond
17th March 2004, 22:15
vobsub in mp4 can be created with nero recode2
vorbis in mp4 can be created with a compile of this mpeg4ip mod (http://www.maersk-moller.net/projects/mpeg4ip/) :)
SeeMoreDigital
17th March 2004, 22:27
Originally posted by KpeX
Why do you need to use the Xcard? Just use the TV-out and Audio-out with any good player (MPC/VLC/Zoomplayer/ etc.) I like my remote control, chapter ability (using simple bookmarks) and component YUV output too much to change.

I've tried software options but me and my WXGA plasma prefer the Xcard. Which is why I also encode using 720x576 anamorphic frame sizes!

Cheers