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dpriest

macrumors regular
Original poster
Nov 18, 2014
117
1
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 ATV3. I want the mp4 file to have the versatility of playing audio through either a receiver or the TV, but not both at the same time because only one TV in the house has a receiver surround system that it is hooked up to and I have an ATV connected to another TV without a receiver. I would like to preserve the original ac-3 audio (5.1 ch) quality to play through my Yamaha receiver so that's why I am selecting AC-3 passthru for one of my audio tracks in Handbrake.

When I encode only one audio track with AAC, I can hear audio on my TV. 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).

Additionally, 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 track is so the file can play sound on different devices. I also thought that if there is both AC-3 and AAC, then ATV will detect the aac and decode it. This is very frustrating.
Thank you for your help in advance.
 
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 ATV3. I want the mp4 file to have the versatility of playing audio through either a receiver or the TV, but not both at the same time because only one TV in the house has a receiver surround system that it is hooked up to and I have an ATV connected to another TV without a receiver. I would like to preserve the original ac-3 audio (5.1 ch) quality to play through my Yamaha receiver so that's why I am selecting AC-3 passthru for one of my audio tracks in Handbrake.

When I encode only one audio track with AAC, I can hear audio on my TV. 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).

Additionally, 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 track is so the file can play sound on different devices. I also thought that if there is both AC-3 and AAC, then ATV will detect the aac and decode it. This is very frustrating.
Thank you for your help in advance.

Not sure if this is the issue or not as handbrake usually does it correctly with the ATV presets but the AAC track needs to be the default audio track. I use subler to do this which is mac only. If you have access to a mac use subler to open the file. Make sure AAC track is checked and AC3 track is unchecked. Then save and retry playing with TV and receiver. Not sure what the windows equivalent is. Looks like xmedia recode does similar things but don't know if you can change default audio track. Will need windows users to chime in here.
 
Yes, indeed I do have a MacBook Pro and love it. I also have a pc and hate it. Anyway, I thought with Handbrake, if Audio Track#1 is AAC and Track#2 is AC-3, then shouldn't AAC be the default? On another note, I don't want anyone to get the wrong idea about me downloading the movie Frozen. This is a perfectly legal copy as it was a paid digital download.
 
Order doesnt matter. Try opening with subler and see what it's set as. If it's already correct than I don't know.
I believe the AAC track needs to be enabled (checkmark in Subler), and AC-3 track needs to be disabled (checkmark cleared).
subler_subtitle_settings.png
 
Thanks for the visual of Subler. If I uncheck AC-3 and just keep AAC then won't the AC-3 track be unavailable to play through my surround system?
 
While it's not necessarily intuitive, all tracks present can still play, checked or not. The checks seem to indicate which is default. You can actually check more than one which doesn't make sense to me though and doesn't work at least with atv.
 
I'll give it a go. That seems like a bit of a pain, because after I use Handbrake to encode, then there is another step with Subler to do this. Too bad there isn't a program that can do it all.
 
What preset are you using in Handbrake? Handbrake always does it correctly for me with the ATV3 preset sourced from DVD or blu-ray rips. I've actually only come across this issue with some other software not doing it correctly.
 
This recent video is an m2ts file that I transferred from my DVR to my MBP via firewire. It was the last Yankee home game with Derek Jeter in HD. The audio is AC-3 (5.1 ch). In the first audio track, I select AAC (facc) as the codec, bitrate 160, samplerate is 48, Mixdown is stereo. I click the add track tab to create a second audio track where this one I select AC-3 Passthru.

On my ATV is messed around with the audio settings. When I select Dolby Digital to ON, then no sound comes through the TV. It only comes through the receiver. When I set Dolby Digital to AUTO then I do get sound through the TV, but on my Yamaha receiver, the display shows the audio as Pro Logic instead of Dolby Digital. Now here is a stupid question: If the receiver is displaying the audio as pro logic instead of Dolby Digital, does that mean I am not taking full advantage of the AC-3 track and not getting the high quality surround sound?
 
When I select Dolby Digital to ON, then no sound comes through the TV. It only comes through the receiver. When I set Dolby Digital to AUTO then I do get sound through the TV, but on my Yamaha receiver, the display shows the audio as Pro Logic instead of Dolby Digital.

I believe the Auto setting uses the HDMI handshake to determine the capabilities of your device. If your TV reports that it cannot do Dolby Digital, the Apple TV will use the AAC file. When you set DD to ON, it sends the AC3 track regardless of what your TV says.

I am reporting my own observations with my equipment over the years.

A.
 
Right. That makes sense. But I am still wondering when DD is set to Auto, the display on my Yamaha receiver says Pro Logic.
 
First step is to double check the settings in subler and fix it if wrong. If that's not it then maybe there's something funny about your setup. Yes, if receiver does not display dolby digital indicator it is not decoding the AC3 track.

How are the ATV, TV and receiver all hooked up to each other?
 
Right. That makes sense. But I am still wondering when DD is set to Auto, the display on my Yamaha receiver says Pro Logic.

My understanding is that you have a TV and receiver connected to your Apple TV? The Apple TV asks the TV 'can you do DD', the TV says 'no', and so the Apple TV sends the AAC track, which is usually a downmix of AC3 to Pro Logic.

A.

Addendum: Your followup posts tells me that it is probably acting as I described.
 
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The ATV is connected to my TV via HDMI and to my receiver via Digital Optical.
 
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