ATV 4K: Only shows one of two audio tracks

[pullman]

Greetings and salutations

I have a ripped DVD, shared from my iTunes, which I wish to watch on my ATV 4K.

I know I can swipe up and select audio options, but for some reason the ATV only shows one of the two audio tracks that are in the file. Annoyingly the track that's shown is the director's commentary and not the main audio.

In the TV app on my Mac I am able to switch between the two audio tracks.

Does anyone know what might cause the ATV not to display both audio tracks?

Thank you very much in advance
Philip

 

[DankeBrutus]

This may sound silly but what format is the commentary in and what format is the primary audio inÉ

 

[pullman]

This may sound silly but what format is the commentary in and what format is the primary audio inÉ

Thank you very much for replying. This what Finder says about the file which I think means the audio is AAC and AC3. If I open the file in Handbrake the two audio tracks are listed as "AAC LC 2.0ch 164kbps" and "AC3 2.0ch Dolby Surround 192 kbps". Perhaps it's a compatibility issue?

cheers
Philip

 

[DankeBrutus]

It may be that your TV or Apple TV doesn't support AC3. It's unlikely but I'm just spitballing. I assume the higher bitrate surround sound track is the primary audio. In Handbrake which track comes up first? My home media library is not shared through iTunes but through Plex so I'm not sure if you're supposed to see both tracks. One way you could test that is seeing if you have the same audio issue when playing the file via the VLC Apple TV app.

You could also create a copy of the file then use FFMPEG to convert the AC3 track to AAC, but that is more involved and shouldn't be necessary.

 

[pullman]

Yes that turned out to be it. I re-encoded the file and switched the AC3 track's codec from passthrough to AAC and now it appears on the ATV and is audible.

Really strange that this happens. I have read that there are certain types of AC3 which do not play but I was under the impression that it is a broadly supported format. And it plays in the TV app on the Mac of course. I may actually have to re-encode quite a bit if this problem reappears (ugh).

Thank you again for having helped me. I really appreciate it.
cheers
Philip

It may be that your TV or Apple TV doesn't support AC3. It's unlikely but I'm just spitballing. I assume the higher bitrate surround sound track is the primary audio. In Handbrake which track comes up first? My home media library is not shared through iTunes but through Plex so I'm not sure if you're supposed to see both tracks. One way you could test that is seeing if you have the same audio issue when playing the file via the VLC Apple TV app.

You could also create a copy of the file then use FFMPEG to convert the AC3 track to AAC, but that is more involved and shouldn't be necessary.

 

[priitv8]

For aTV compatibility, you must have one AAC 2.0 (stereo) track and can have AC3 or E-AC3 track that is secondary and not selected.
AAC stereo track must be the fallback track for multichannel track.
BTW, having AC3 or E-AC3 track only makes sense if you want to have multichannel sound.
I never encode or pass through AC3 in 2.0 format, but always re-encode them into AAC 2.0.

Subler to rescue:

 

[Non-Euclidean]

For aTV compatibility, you must have one AAC 2.0 (stereo) track and can have AC3 or E-AC3 track that is secondary and not selected.
AAC stereo track must be the fallback track for multichannel track.
BTW, having AC3 or E-AC3 track only makes sense if you want to have multichannel sound.
I never encode or pass through AC3 in 2.0 format, but always re-encode them into AAC 2.0.

Subler to rescue:
View attachment 2597822

Huh. I have been ripping (MKV) and reencoding (Handbrake) Fallout/Strange New Worlds and Andor for Synology NAS host (Plex), Plex client on TV.

I was used to using passthrough for the audio. I discovered no joy with True HD (on the Fallout), because not much can play it, so I switched to the included 5.1 AC3 using pass through.

So if I switch to aTV in the future I will be hosed? I was contemplating getting aTV and making the Roku TCL TVs dumb. This would be the next gen 4k aTV, which I would hope would support more audio formats.


Edit: OK, did some more searching. Forget passthrough, since all codecs passed through need to be licensed. Crap.

I already installed Subler and need to start using it.

 

[pullman]

Thank you very much for the explanation.

Just so I understand, by "is secondary and not selected" do you mean that the AAC track must be the first one in Handbrake's track list under the Audio tab?

Or must I add the Subler step and manually select the AAC as fallback for any multi-channel track (which can then be at any place under the Audio tab)?

For aTV compatibility, you must have one AAC 2.0 (stereo) track and can have AC3 or E-AC3 track that is secondary and not selected.
AAC stereo track must be the fallback track for multichannel track.
BTW, having AC3 or E-AC3 track only makes sense if you want to have multichannel sound.
I never encode or pass through AC3 in 2.0 format, but always re-encode them into AAC 2.0.

Subler to rescue:
View attachment 2597822

 

[priitv8]

The order of tracks is not important.
In Subler view, the aac track must have a checkbox selected, corresponding AC3 track not.
In the track metadata, AC3 track must have the stereo aac track listed as its fallback track (as shown on my screenshot).