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apfhex

macrumors 68030
Aug 8, 2006
2,670
5
Northern California
So what exactly CAN get true surround out of Apple's 6-channel AAC movie trailers? Only a product like the Firewave and speakers that have 6-channel input? Never made much sense to me. :confused:

Anyway, the lack of real 5.1 and the limited codecs the AppleTV can play means I definitely won't be getting one anytime soon. Heck, even my cheapo DVD player can play some Divx/Xvid files and get 5.1 (AC-3) sound from them.
 

localoid

macrumors 68020
Feb 20, 2007
2,447
1,739
America's Third World
So what exactly CAN get true surround out of Apple's 6-channel AAC movie trailers? Only a product like the Firewave and speakers that have 6-channel input? Never made much sense to me. :confused:

Correct. I have a Firewire sound device, w/6 channels out, and Apple Quicktime 5.1 surround sound will playback in iTunes or QT Pro on discrete channels if "speakers" are configured accordingly in Audio Midi Devices (in Utilities).

In "theory" at least, there are other methods that should allow some-degree of surround sound playback; those topics and theories are addressed in the article mentioned at the beginning of this thread @ ThisMuchIKnow, from which the following quote is taken:

If Apple are saying “we support 5.1″ to mean “we support Dolby Pro Logic II”, what they really mean is:

“If you have an existing QuickTime-friendly movie with a stereo soundtrack, which happens to have Dolby Pro Logic II 5.1 information matrix-encoded into it, then we’ll happily play that stereo soundtrack to your amplifier. If your amplifier then happens to detect and decode the Dolby Pro Logic II encoding, then you’ll get 5.1 sound out of your speakers.”

But at this point in time we have no real proof that Apple actually said :apple: tv does support 5.1, and actual "controlled experiments" with Apple TV in regards to surround sound have been few and far between. So, at this point in time, what we don't know (for certain) about :apple: tv amounts to more than we actually do know (for certain)...

Someone should take a known QT 5.1 sound file, play it via :apple: tv that's correctly connected to a receiver w/Dolby Pro Logic and report what they're able to get (sound wise) out of this experiment.

Until then... confusion will reign in regards to this topic.
 

maurj

macrumors newbie
Original poster
Mar 25, 2007
3
0
Someone should take a known QT 5.1 sound file, play it via :apple: tv that's correctly connected to a receiver w/Dolby Pro Logic and report what they're able to get (sound wise) out of this experiment.

Localoid,

Do you mean a known 6-channel AAC file? I think that's what the guy at ThisMuchIKnow did, so that seems a pretty good test of how it treats 6-channel (5.1) AAC tracks.

Or do you mean a known Dolby Pro Logic II track? I've not seen a 'test' DPL II file, to be sure of what's coming out of each speaker. But since the DPL II is encoded into a stereo signal, there's no reason why this shouldn't play via QuickTime / Apple TV to a DPL II amp...
 

mkaake

macrumors 65816
Apr 10, 2003
1,153
0
mi
I don't know. I kinda think that 5.1 is overrated to begin with.

I thought so too until I got a 5.1 system.

Now, watching movies w/o is... disappointing. I find it more important to have 5.1 than I do to have HD...

Just MHO, but that's the main point of contention between me and the macTV...
 

localoid

macrumors 68020
Feb 20, 2007
2,447
1,739
America's Third World
Localoid,

Do you mean a known 6-channel AAC file? I think that's what the guy at ThisMuchIKnow did, so that seems a pretty good test of how it treats 6-channel (5.1) AAC tracks.

Or do you mean a known Dolby Pro Logic II track? I've not seen a 'test' DPL II file, to be sure of what's coming out of each speaker. But since the DPL II is encoded into a stereo signal, there's no reason why this shouldn't play via QuickTime / Apple TV to a DPL II amp...

I'm advocating rounding up some test files of various types and test them.

.. Someone find a trailer on iTunes that's known to be surround sound.

.. Has anyone tried making a QT reference movie to a AC-3 file?

.. There's QuickTime movie with AAC encoded 5.1 channel audio available for d/l'ing near the bottom of that page. Someone try it on their atv...

To (accurately) determine what does or doesn't work, on the atv end, you'd first need some test files (known to work in iTunes), etc. Does this logic make sense? :)
 

patrick0brien

macrumors 68040
Oct 24, 2002
3,246
9
The West Loop
-All

Apple couldn't get HDMI cert without the hardware being capable of 5.1.

That means it's likely locked off for now, and we all know that the content isn't there yet...
 

patrick0brien

macrumors 68040
Oct 24, 2002
3,246
9
The West Loop
Speak for yourself :p

This is actually one of the basics of a good movie experience.

-Diatribe

Fancy seeing you here.

You though 5.1 was nifty, 7.1 is creamy goodness too ;)

Yes, you're right. Must... have... multi... channel... well... balanced... speakers... good... acoustics......popcorn.
 

Diatribe

macrumors 601
Jan 8, 2004
4,256
44
Back in the motherland
-Diatribe

Fancy seeing you here.

You though 5.1 was nifty, 7.1 is creamy goodness too ;)

Yes, you're right. Must... have... multi... channel... well... balanced... speakers... good... acoustics......popcorn.

Hehe, same to you :)

Yeah I could see myself with a nifty 7.1 setup with some front presence speakers as well, but I guess that'll have to wait until I have a dedicated movie room :D

Anyway, I am with you, sound, image and food are the most important prequisites of a good movie evening besides the movie itself of course. :)
 

musicpenguy

macrumors 68000
Oct 29, 2006
1,824
734
Wouldn't it play 5.1 if all the necessary codecs are added to the ?TV? Say from an AC-3 audio from an AVI Container as it does on the mac???
 

sycho

macrumors 6502a
Oct 7, 2006
865
4
I'm fairly certain someone said the chipset used was capable of 5.1
So? The chipset in the Intel Mac's is 5.1 compatible, but still only outputs 2 channels. What we'd like to know is if the HDMI output will spit out 5.1 or even 7.1 audio
 

TBi

macrumors 68030
Jul 26, 2005
2,583
6
Ireland
Shouldn't the Apple TV just pass through the AC3 information to a decoder if you have one?
 

pilotError

macrumors 68020
Apr 12, 2006
2,237
4
Long Island
arstechnica.com did an in-depth review and was unable to get it to do 5.1 surround.

http://arstechnica.com/reviews/hardware/appletv.ars

Athough it is capable of doing 5.1, I think we are going to need a software update.

Although Apple makes no claims regarding Apple TV's ability to play "full" surround sound, it is emerging as a major sticking point among audiophiles. To be sure about the Apple TV's audio capabilities, we enlisted the help of a friend of ours, one of our readers, and fellow forum member John Averitt. What we found confirmed most people's fears: Apple TV is limited to playing files that are present in iTunes, which limits the number of 5.1 file types. A 5.1 AAC QuickTime movie gave only 2-channel sound through the Apple TV, or (at best) Dolby Digital Pro Logic II when played through the optical connection. This is different than Front Row behavior on a Mac mini—Front Row uses QuickTime and all of its associated plugins. With Front Row, Dolby Digital (AC3) encoded audio can be output through the optical cable, giving "true" surround sound. Since there is no way (that we know of) to play Dolby Digital or DTS encoded audio in iTunes, that leaves AAC 5.1 for the Apple TV, which the device treats the same way as a default 10.4 QuickTime install does—by putting all five channels into two. So, there is no 5.1 surround sound, just the older Pro Logic II, two-channel Dolby format.

The inclusion of the optical port like all the other HD settings suggests that Apple is going to start selling or at least thinking about selling HD 5.1 content. If that wasn't the case, Apple could have made a much cheaper media extender for the iTunes Store than the Apple TV to handle their current content.
 

princealfie

macrumors 68030
Mar 7, 2006
2,517
1
Salt Lake City UT
Speak for yourself :p

This is actually one of the basics of a good movie experience.

True but for me, a good movie makes it more important than fidelity to the original theatrical experience.

Of course, I heard that Frauenhofer was updating the mp3 codec to include built in 5.1 encoding a few years ago. What happened to that project?
 

patrick0brien

macrumors 68040
Oct 24, 2002
3,246
9
The West Loop
Sweet :) What receiver are you using?

-sycho

Oh boy. Umm, let's just say I'm running pretty near an 'ideal' system.

All HDMI (except the DVD player, it's Component)

DVR, :apple:TV, and that DVD player go to a Denon AVR-4306, which, in turn HDMI to the Sharp Aquos.

The Receiver is technically 7.1, but I particularly like it's intelligence. I could be watching plain'ol SD stereo TV and it'll accurately interpolate the 2 channels into 5.1 for me. Needs a LOT of ventilation though.
 

sycho

macrumors 6502a
Oct 7, 2006
865
4
ok, since people just seem to post in here about stuff we've known for a while now, i'll do this:

SPDIF output is currently only stereo PCM, no Dolby Digital or dts
Don't think that the AppleTV can be updated to output Dolby Digital for any surround content. The SPDIF output works like any other Macintosh: Outputs PCM for system and regular sounds, and will out PASS Dolby Digital and dts, not encode it.<edit> apple hasn't yet enabled Dolby Digital or dts passthough</edit>

The HDMI output should be able to output 5.1, or even 7.1 output, but this does not seem to have been tested yet.
If this way works, it will only work with a Multi-Channel receiver, not a TV with HDMI and SPDIF out.


I'm glad we have got this out of the way.
 
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