Handbrake AC-3 Passthru No Sound On TV

[maverickluke]

I searched this forum and did not find the answer for this question. I apologize if this has been answered before, and I am a bit of a newbie to all of this.

I have an m2ts video that has two AC-3 (5.1 ch) audio tracks. I want to convert it to an mp4 file to play on my appleTV 3. I would like to encode the audio so I can play the original ac-3 audio (5.1 ch) without compressing it through my Yamaha receiver and also on a regular tv wihout a receiver. I am using Handbrake to encode the file and when I encode the audio with aac and mix down to stereo, I can hear sound on both the stand alone tv and on my 5 speakers connected to the receiver. When I add a second audio track and select AC-3 passthru, I can hear sound on the speakers through my receiver only, which happens to be great dolby digital surround sound, but I cannot hear sound on my tv.

I changed the order of the audio tracks which made no difference. (eg. audio track 1 aac, and track 2 ac-3, and vice versa) I am trying to preserve the great sound of the original AC-3 audio to play on my surround system so I selected AC-3 passthru since the original audio is AC-3. Thanks for all help in advance.

[ndjamena]

Stupid question: are you going for TV and receiver at the same time?

Another stupid question: How do you know you're actually hearing AC3?

It sounds as if in both circumstances the apple TV is attempting to stream the AC3 through HDMI (without converting it to PCM like it does with AAC) but that the TV doesn't accept 5.1 AC3 through HDMI.

[ndjamena]

http://arstechnica.com/apple/2012/05/creating-videos-with-51-audio-for-the-apple-tv-mac-and-ios/

The AppleTV cannot decode AC3, if your TV can't accept it then you'll hear nothing.

You could try this thread:
https://forum.videohelp.com/threads/368436-ffmpeg-force-default-audio-track-in-mp4-container

Or maybe there's something in the AppleTV setting that will automatically select AAC before AC3...

[maverickluke]

Not a stupid question. I apologize for not being clearer. I want the mp4 file to have the versatility of playing through either a receiver or the tv, but not both at the same time. Only one tv in the house has a receiver surround system that it is hooked up to. When I play the mp4 file through my apple tv, the display on my Yamaha receiver is indicating Dolby digital as opposed to pro logic.

[maverickluke]

I understand AppleTV cannot decode AC-3, but can decode aac. I downloaded the movie Frozen which is an mp4 file and did not touch it with Handbrake. The sound plays through my tv as well as my receiver. I checked the file with MediaInfo and there are 3 audio tracks: Audio#1 is AAC 2 channel, Audio #2 is AC-3 (5.1 ch), and Audio#3 is AAC (7.1 ch). There must me something I am doing in Handbrake because why would Frozen play sound through my tv? I have checked other forums and I thought the reason for adding more than one audio is so the file can play sound on different devices. I also thought that if there is both AC-3 and AAC, then apple tv will detect the aac and decode it.

[ndjamena]

Does it play the 7.1 AAC or the stereo? It's possible it's choosing the best audio available.

Or it's possible Handbrake is using the AC3 track as the default. Try the second thread and see if changing the defaults works (or at least check which is disabled and which is enabled).

[jman98]

This kind of problem is exactly why I say repeatedly that unless you simply cannot live without iTunes (ie. you bought a bunch of videos through it), AppleTV is a terrible product and just about everything else is better.

[maverickluke]

jman98, do you have any experience with appletv? I have about 2TB of movies that I want to stream from my computer to my tvs in the house. I have a pc and a MacBook pro. In a couple of years, I am burying my PC and going to replace it with an imac because in my opinion PC = HEADACHE. right now everything is in iTunes. What other device would you suggest that will do what the appletv does but better, and why does appletv play sound in the movie Frozen and not in the videos I encode with Handbrake? Also, I thought there was a way with Handbrake to assign the default audio track by putting it as Audio#1.

[ndjamena]

Yup, handbrake disables all but the first audio track, so it looks as though the AppleTV is doing this deliberately.

*sigh*

If there's no setting in the AppleTV itself, you could go stupid and add a 7.1 AAC track as a third audio.

[maverickluke]

I'm not understanding what you mean by ATV doing this deliberately. If handbrake disables all but the first audio track and the first audio track is AAC, then why can't I hear sound on my TV? When there is only one audio track (AAC) ATV plays the sound fine through my TV.

[ndjamena]

Because disabling all but one track essentially sets that one track as the default, but for whatever reason the AppleTV is overriding that default. It's possible there's a setting in the ATV causing it, or it's possible the TV is agreeing to receive the AC3 even though it can't do anything with it, or it's possible the ATV is using the settings it retrieved from the receiver. Or maybe this is just what the ATV does.

Have you looked through the ATV settings to see if something relevant is there?

[maverickluke]

I will dive into my ATV settings further to see if I can find anything

[johns0]

I downloaded the movie Frozen which is an mp4 file and did not touch it with Handbrake.

Please do not discuss movies you have downloaded illegally,it is against the law and forum rules,this thread is closed.