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View Full Version : Enabling AC3 Passthrough On Snow Leopard...?




mucky.fingers
May 29, 2010, 03:15 PM
Hi Folks,

I have encoded a few DVDs using Handbrake, using the AppleTV preset but unfortunately they don't seem to have 5.1 Surround Sound.

The file seems to encode correctly, track 1 is Stereo, track 2 should be AC3 5.1 but only plays in stereo.

As I have not changed the preset I can only assume I need to change some settings somewhere? I have Perian installed.

Please can someone point me in the direct of a step by step guide (or help me out??)

For reference I'm running the latest entry level mac mini connecting with toslink cable via the adaptor into the headphone jack.

Please help. Thank you kindly



mucky.fingers
May 31, 2010, 04:59 AM
Sorry for bump but 82 views and no replies I was getting desperate.

Anyone?

NJuul
May 31, 2010, 06:18 AM
I'm guessing whichever player you use to play your videofile doesn't pass-through the AC3 track. Make sure you choose the AC3 track, many players will by default select the first track, which is stereo.
You connect your mini to a receiver using a toslink cable (right?). On the receiver, does AC3 light up?
I would suggest you looked into something like Plex as a video player, here you can easily choose which audio track should be played, and it is perfect for a mini-based media center.

Also of course check that you use the latest handbrake, with updated presets.

Cave Man
May 31, 2010, 07:10 AM
What software are you using? Quicktime is pretty much useless.

Do you have the optical input on your receiver enabled? On my Onkyo, the VIDEO1 audio input (the input for my ATV optical cable) was factory set to the RCA ports. I had to go through a menu to change that to optical.

mucky.fingers
May 31, 2010, 01:22 PM
Thanks both for your replies.

Sorry I should of said I am already using PLEX.

What I have found is that when I use the MKV container everything works as it should, DD 5.1, lights up correctly on receiver etc. Sounds fantastic.

It is only when I try and convert the original source using Handbrake AppleTV Settings, using track 2 (which should be the AC3 Passthrough) that it doesn't seem to work, Plex says both tracks are Stereo.

Ideally I'd like to convert everything as m4v/mp4 to get smaller file sizes as MKV has rather large file sizes but don't wan't to lost 5.1.

Settings all seem OK in PLEX.

Again, thanks to anyone that can help.

fpnc
May 31, 2010, 07:34 PM
Here is a link to a post which may help (offers link to step-by-step guide):

http://forums.macrumors.com/showthread.php?p=9918991&highlight=audio#post9918991

Cave Man
May 31, 2010, 08:36 PM
Here is a link to a post which may help (offers link to step-by-step guide):

I really doubt that link to a link is going to work with Snow Leopard. Getting digital passthrough in Leopard required such a workaround, but Snow Leopard broke those approaches. If Plex isn't doing it, there's something amiss with the file or a setting.

fpnc
May 31, 2010, 09:10 PM
I really doubt that link to a link is going to work with Snow Leopard. Getting digital passthrough in Leopard required such a workaround, but Snow Leopard broke those approaches. If Plex isn't doing it, there's something amiss with the file or a setting.
The instructions were written by the person who implemented the Perian code to support multi-channel audio and were updated in Dec. 2009, so it may work.

Alrescha
May 31, 2010, 09:49 PM
I really doubt that link to a link is going to work with Snow Leopard. Getting digital passthrough in Leopard required such a workaround, but Snow Leopard broke those approaches. If Plex isn't doing it, there's something amiss with the file or a setting.

Using Snow Leopard with the current version of iTunes, getting digital output/AC3 passthru on iTunes store content requires clicking on the speech bubble in the on-screen display and choosing 'Surround Audio'.

Clearly the parts are all there. I don't know why it doesn't work on Handbrake material.

A.

suss2it
May 31, 2010, 11:06 PM
Are you sure that the original track is AC3 and not DTS?

NJuul
Jun 1, 2010, 03:12 AM
Are you sure that the original track is AC3 and not DTS?

Good point, OP, try to open the m4v file in quicktime, and go to "Window", and click on "Movie inspector". Does the file say 5 channel AC3 in "source"?
Also, you can try to open Handbrake (you are using 0.9.4, right? With updated presets?), open your source file, choose the ATV preset, go to the audio tab, and make a screen dump of it. Then we can see if it says AC3 (5.1) pass-through.

dynaflash
Jun 1, 2010, 08:54 AM
Good point, OP, try to open the m4v file in quicktime, and go to "Window", and click on "Movie inspector". Does the file say 5 channel AC3 in "source"?
Also, you can try to open Handbrake (you are using 0.9.4, right? With updated presets?), open your source file, choose the ATV preset, go to the audio tab, and make a screen dump of it. Then we can see if it says AC3 (5.1) pass-through.
Or probably even more helpful would be the HandBrake Activity log from the scan. That pretty much tells the whole story. Paste it on something like pastebin.ca and put the link here.