[AppleTV2] HOW-TO to enable AC3 and DTS output for Apple TV 2

don't change these settings in the xml directly ... change it in the gui ... i would recommend you delete that part from the xml and reconfigure your audio in the xbmc settings...

mystiqu Wrote:Hey

Here is my config that does not work:

ATV2
IOS 4.3 with XBMC PRE-11.0
Receiver: Onkyo TX-SR607
Video source: HDMI
Sound source: Optical
Video and Sound all goes through the receiver

ATV2 4.3 Jailbreak -> HDMI output (Video) -> Onkyo Receiver -> LG TV
ATV2 4.3 Jailbreak -> HDMI output (Sound) -> Onkyo Receiver -> LG TV

Code:

<audiooutput>
        <ac3passthrough>true</ac3passthrough>
        <audiodevice>Default Output Device</audiodevice>
        <channellayout>7</channellayout> //tried 5.1 also
        <dontnormalizelevels>true</dontnormalizelevels>
        <dtspassthrough>true</dtspassthrough>
        <mode>2</mode>
        <passthroughaac>false</passthroughaac>
        <passthroughmp1>false</passthroughmp1>
        <passthroughmp2>false</passthroughmp2>
        <passthroughmp3>false</passthroughmp3>
    </audiooutput>

I think mode stands for:
1: optical/coax
2: HDMI

No matter which settings I play around with I just get static output when ac3/dts passthrough is enabled

Did you try exiting XBMC, and going to Apple TV > Settings > Audio & Video > Audio Output and setting it to "16 bit"?

Quote:Did you try exiting XBMC, and going to Apple TV > Settings > Audio & Video > Audio Output and setting it to "16 bit"?

Yes - unfortunately it didn´t make any difference

mystiqu Wrote:Yes - unfortunately it didn´t make any difference

I just reverted back to the original settings everywhere (sound: auto), not dts and ac3 passthrough etc and made another try - guess what?

It works

I´ve no idea why it worked this time though - the only thing I can think of is that I now begun with setting the sound to 16 bit before enabling ac3 and dts passthrough.

Anyhow - thanks alot everyone

Maetrik Wrote:Working:
ATV2 4.2.1 ---> HDMI ---> Onkyo TX-SR507 ---> Samsung TV (via HDMI again) - no sound problems or statics at all.

I have the exact same setup as Maetrik and my receiver is not detecting Dolby Digital when playing video through XBMC. The receiver does however however detect Dolby Digital just fine when playing Netflix on the ATV2 or a rented movie from iTunes.

Moreover, I can play a file through the XBOX Media Center, that is connected the same way as the ATV2, and it will detect Dolby Digital. The same file does not play in Dolby Digital when played through XBMC.

The single point of failure here seems to be XBMC.

Maetrik, did you have to change anything in the guisettings.xml file to get your setup working? So far I have changed the following two options in that file (changed from false to true):


<ac3passthrough>true</ac3passthrough>
<dtspassthrough>true</dtspassthrough>

broughaj Wrote:I have the exact same setup as Maetrik and my receiver is not detecting Dolby Digital when playing video through XBMC. The receiver does however however detect Dolby Digital just fine when playing Netflix on the ATV2 or a rented movie from iTunes.

Moreover, I can play a file through the XBOX Media Center, that is connected the same way as the ATV2 and it will detect Dolby Digital.

The single point of failure here seems to be XBMC.

Maetrik, did you have to change anything in the guisettings.xml file to get your setup working? So far I have changed the following two options in that file (changed from false to true):


<ac3passthrough>true</ac3passthrough>
<dtspassthrough>true</dtspassthrough>

Just a thought, have you selected your audio output and speaker config appropriately in System -> System -> Audio output ?

beddy Wrote:Did you try exiting XBMC, and going to Apple TV > Settings > Audio & Video > Audio Output and setting it to "16 bit"?

Thank you very much for your suggestion, that was the magic setting that made the whole thing work for me. I do currently still have AC3 and DTS passthrough enabled in xbmc, but after changing that output setting from AUTO to 16bit the DTC and AC3 starting working through my receiver and the static/feedback was gone.

Thanks again!

pasjk Wrote:I set up XBMC for optical out- AC3 and DTS- in the ATV2 XBMC settings menu.
Get a horrible sound in playback through my receiver.
If I go back and set for analog all is ok, using Dolby Prologic or any other setting (except of course it won't show Dolby Digital setting) on the receiver.
So,I went into the files as shown below.
I have never changed anything prior to this. Got in just fine.
I just installed XBMC last week.
For me, the "false" was already "true" in both lines.
Any suggestions? Is there something I need to set differently in XBMC on the ATV2 or in ATV2 itself . I set ATV2 to 16 bit just in case of a problem. I was using default. I was not having any difficulties with sound through TV or sound system, so I will put it back to auto.



Just tinkered around a bit in /var/mobile/Library/Preferences/XBMC/userdata/guisettings.xml and flipped these two on, hoping it'd work, and it did:

In the <audiooutput> section, change "false" to "true" on the following entries:

<ac3passthrough>false</ac3passthrough>
<dtspassthrough>false</dtspassthrough>

I am now getting AC3 passed through from the SPDIF out to my 7.1 receiver. Overall video playback is also a lot smoother now that it's not downmixing to 2.0 audio it seems.

I can confirm that this works with my setup as well. I have Apple TV 2 4.3 latest build of XBMC (not nightly). Old Pioneer Receiver with Optical input from the Apple TV 2. Thanks!!

I also discovered that if I use my manual setting rahter than auto on the Pioneer receiver and then choose Dolby Digital, I do get 5.1 although the little redlight does not go on.

For someone who is new at all of this what exactly does enabling this option do. Does it let us hear certain sound files or what. I have a home theater system with the ATV 2 hooked up to it by hdmi. It's 5.1 and has two front speakers, center, subwhoofer, but I haven't hooked up the two surround sound speakers.

Can someone explain why this feature would be helpful.