How many ac-3 tracks in m4v container?

[Number6]

Hi, I was wondering if I could put more than one ac-3 track in an m4v container. Well, I probably can, but will the Apple TV be able to make sense of it? Which ac-3 track would be played by default if the Apple TV is hooked up to a surround amplifier? I know switching aac tracks is no problem, I am just not sure what I should do, since I have several ac-3 tracks for one movie which I want to keep in their original quality.

Thanks in advance!

 

[priitv8]

IMHO if they have different language codes, you can.
Default language to play is chosen from the preferences set in AppleTV Settings.

 

[Number6]

Okay, thanks! Guess I'll just run the encode (although this is gonna take quite some time) and see what happens...

 

[Menneisyys2]

Okay, thanks! Guess I'll just run the encode (although this is gonna take quite some time) and see what happens...

1. Do you run a full encode (incl. video) just to change the format of some of the audio tracks?

2. You can put any number of AC-3 tracks in an m4v file.

 

[dynaflash]

You want first track aac and second track same language AC3.

Then after that you can add as many AC3 tracks as you want and can choose each from the menu on that atv. Beware its going to expect however that you have track 1 (english) aac and track 2 (english) AC3.

The atv will auto detect which track to use depending on your audio setup.

After that you can (as I said) add additional AC3 tracks presumeably in other languages but you will have to manually select them with the atv remote.

Beware not using the native language track in aac + AC3 for the first two tracks as in past atv updates not doing so has broken only running all AC3 tracks.

 

[Number6]

Thanks for all the replies! My encode (with video, two aac tracks, and two ac-3 tracks) is finished. It works, although I am not quite sure about the "native language" thing Dynaflash mentioned. So the first aac and the first ac-3 tracks have to be English? What if it is a foreign movie that doesn't even have English language tracks?

I've done those with no problems, and my Apple TV is set to English as the main language.

Maybe I am just confused now, it's late (early) here in Europe. I'll check back tomorrow..

 

[priitv8]

I have movies that have only spanish or german soundtracks and they play without problems. But I always make sure there is a pair of AAC and AC3 tracks for each language.
The commentary tracks (usually only in stereo), even if originally in AC3 2.0 I always encode into AAC.
AAC track is also a must if you want to play the movie back with sound on iPad or iPhone, wothout 3rd party players.

 

[Number6]

Well in that case my encode might be faulty. I have the tracks in the following order:

1. English aac
2. German aac
3. English Dolby 2.0 mix ac-3
4. English Dolby 5.1 mix ac-3

I cannot try out the file in my home theater right now, but playback in iTunes gave me all 4 tracks (although it moved the German language to position 4 in the display). I will give the file a workout later.

But if REALLY have to have pairs (aac+ac-3) for every language then I might have to redo quite a few encodes that I've done in the following order:

1. English aac
2. German aac
3 English Dolby 5.1 ac-3

I just pray that this is not a problem because there might be nearly a hundred files which I encoded that way. Please God, no...

 

[priitv8]

I guess your problem lies in having 2 english tracks in AC3.
Someone just recently had the similar problem here:
https://forums.macrumors.com/threads/1681831/
Just verified today - also files without AAC tracks at all play OK on AppleTV. But they will be mute on iPad and iPhone.

 

[Number6]

So after checking the file extensively I found that the Apple TV plays all the audio tracks, although it defaults to the 2-ch ac-3 track (not the 5.1 track). But this seems logical since it's the first ac-3 track in the order that I encoded them in. And it's fine as I wish to choose those tracks manually anyway. They all have their merits.

I just hope that no update by Apple will screw up the playback of my more non-standard files. So far everything plays fine. I am only afraid of that re-encode scenario...

 

[Ritsuka]

You can use Subler to set the ac-3 track fallback, so the AppleTV will know which tracks is associated to.