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View Full Version : Does true, easy 5.1 require a software or hardware update?




kavika411
Mar 28, 2007, 04:10 PM
I appreciate anyone's thoughts. I've read several of the ongoing threads about 5.1, including the linked article in the most popular thread. My impression is that if it takes that many words to explain how to do 5.1 in iTunes and/or Apple TV, then it doesn't actually work for the average user. So, my two questions are simply these:

(1) Assuming - as I think we can - that the Apple rolls out a new version of iTunes which is very, very friendly to 5.1, can the current Apple TV handle 5.1? Yes or no?

(2) IF the answer to the first question is 'no,' then can the current Apple TV be fixed with a software/firmware (?) update to run 5.1, or will it take another generation Apple TV? (The current one has an optical out and I thought that could handle 5.1. I may be wrong.)

My questions arise largely from what I just heard Alex Lindsay on Mac Break Weekly say: he is waiting for generation two of Apple TV because he believes it will be 5.1 friendly. Is he right, or can the current one be fixed with a simple software update?

Thank you.



sycho
Mar 28, 2007, 04:44 PM
At the moment, no iTunes Movies have discrete surround, all movies are encoded in Dolby Surround, which uses a stereo track as the medium. While it is should be possible for the AppleTV to output 5.1, it would require a pre-encoded track such as Dolby Digital or dts. The biggest problem right now is that the AppleTV does not have the hardware to convert the 5.1 AAC, on the QuickTime HD trailers, to Dolby Digital or dts, thus limiting the output to Stereo PCM, or possibly 5.1 via the HDMI(While it would be nice and extremly easy for a device such as the AppleTV to output multichannel via the HDMI output, it seems Apple limited this revision to stereo only.).

jeremy.king
Mar 28, 2007, 04:53 PM
It should only be a software update.

The AppleTV contains the Realtek ALC885 audio codec (http://www.realtek.com.tw/products/productsView.aspx?Langid=1&PFid=28&Level=5&Conn=4&ProdID=138), which supports 7.1 audio.

JonHimself
Mar 28, 2007, 04:56 PM
This most important question asked by the OP (to me at least) was that whether 5.1 could be added to Apple TV with a hardware or a software revision? I think I've lost a good 5-6 hours of my life reading thread after thread of info about 5.1 and how it relates to Apple TV but still don't know if it's a software limitation or if Apple would need to release a new hardware config to enable 5.1 (By 5.1 I mean 5.1 from ANY source, whether it is some kind of AAC 5.1 or AC3 passthrough or whatever other way - not just from iTunes media, but from any form we can rip ourselves)

EDIT: Thanks kingjr3, I took too long to type my response.

Diatribe
Mar 28, 2007, 05:02 PM
It is a software issue but not necessarily that of the appleTV firmware but of what is in the media file.
If Apple continues to use AAC 5.1 it is also a hardware issue because something will be needed to decode it, either appleTV transcoding it or a receiver in the future. If Apple puts in DTS or AC3 then nothing would be needed as the signal could be passed through to the receiver and decoded there.

Depending on what Apple intends to do this is more or less tricky.

sycho
Mar 28, 2007, 05:12 PM
It should only be a software update.

The AppleTV contains the Realtek ALC885 audio codec (http://www.realtek.com.tw/products/productsView.aspx?Langid=1&PFid=28&Level=5&Conn=4&ProdID=138), which supports 7.1 audio.

WRONG!!

It is not a software issue people, it is a HARDWARE limitation.

That is the pretty much the same thing in the MacBook, iMac, MacMinis and Mac Pros. All of those only output stereo PCM.

Diatribe
Mar 28, 2007, 05:17 PM
WRONG!!

It is not a software issue people, it is a HARDWARE limitation.

That is the pretty much the same thing in the MacBook, iMac, MacMinis and Mac Pros. All of those only output stereo PCM.

Please, don't spread FUD!

All of them pass a AC3 signal through the digital output well. There is no hardware limitation in Macs that prohibits AC3 pass-through!

sycho
Mar 28, 2007, 05:43 PM
Please, don't spread FUD!

All of them pass a AC3 signal through the digital output well. There is no hardware limitation in Macs that prohibits AC3 pass-through!

There is no AC3 content on iTunes, only AAC:rolleyes: The AppleTV can not convert AAC to AC3, because of a hardware limitation. Go read the first reply to this thread. It is funny, people hear seem to ignore the truth big time when they don't want that answer.

JonHimself
Mar 28, 2007, 05:46 PM
There is no AC3 content on iTunes, only AAC:rolleyes: The AppleTV can not convert AAC to AC3, because of a hardware limitation.

Right, but Diatribe is only correcting your statement about the inablity of Mac computers to do so. (I think)

Diatribe
Mar 28, 2007, 06:02 PM
There is no AC3 content on iTunes, only AAC:rolleyes: The AppleTV can not convert AAC to AC3, because of a hardware limitation. Go read the first reply to this thread. It is funny, people hear seem to ignore the truth big time when they don't want that answer.

Right, but Diatribe is only correcting your statement about the inablity of Mac computers to do so. (I think)

Exactly. Macs can pass AC3 from AC3 encoded media through the optical out. Currently DVD player does this, I am not sure about QT but I think not. Then a receiver decodes it.

AAC 5.1 is a very real problem as no receiver decodes this yet.

I doubt that Apple will include AC3 streams as they are pretty big and would add a lot of file size.

roland.g
Mar 28, 2007, 06:04 PM
This might be off topic but a buddy of mine has a wicked 8.2 system. It has the regular Center, Front L & R, Rear L & R, Rear Surround L & R and a monstrous sub. Add to that a separate Center channel that splits dialogue out to create the feel that two people are talking in space. It is freaky, you feel like you are in between them. Then there is a 2nd device connected through the sub-channel and fed into his couch that acts like force-feedback and sends reverberation through the couch based on the level coming from the sub - kinda like that ambient surround backlight that those tvs do, except for your body. It's not over the top though like a massage chair or anything. He has that hook up to this system that he got from some new AV company, it comes with a screen and projector, and the screen can be up to 65 feet. His is 10' diagonal. The projector is hooked up to a rack that can hold up to 36TB of drives, he currently has 8TB. You load your DVD's in and it copies them full quality and then downloads from their server all the metadata, description, cast, director, genre, poster, etc. When you want to watch something you can sort posters in a grid by genre, title, etc. Or you can select a movie and see the cast and then pull up everything else with that actor or by that director etc. And it's wired to a regular plasma in his bedroom, and in each of his two kids rooms, so everyone can be watching something at the same time. Then again, it was $11,000. But he seems to be quite happy with it. And no Handbrake or Mediafork settings to worry about, it takes it as is. One button and go.

JonHimself
Mar 28, 2007, 06:07 PM
Exactly. Macs can pass AC3 from AC3 encoded media through the optical out. Currently DVD player does this, I am not sure about QT but I think not. Then a receiver decodes it.

AAC 5.1 is a very real problem as no receiver decodes this yet.

I doubt that Apple will include AC3 streams as they are pretty big and would add a lot of file size.

So then, in order to get 5.1 sound from AppleTV, the unit itself will have to 1) transcode 5.1 AAC to AC3 and pass that onto the receiver or 2) Be able to passthrough an AC3 stream from the original file (is that possible at this point?), right? What are the other possible (speaking realistically) options are there (current and future)?

I've spent too much time reading and not enough just asking basic questions about specific things I do not understand.

Keebler
Mar 28, 2007, 06:57 PM
This might be off topic but a buddy of mine has a wicked 8.2 system. It has the regular Center, Front L & R, Rear L & R, Rear Surround L & R and a monstrous sub. Add to that a separate Center channel that splits dialogue out to create the feel that two people are talking in space. It is freaky, you feel like you are in between them. Then there is a 2nd device connected through the sub-channel and fed into his couch that acts like force-feedback and sends reverberation through the couch based on the level coming from the sub - kinda like that ambient surround backlight that those tvs do, except for your body. It's not over the top though like a massage chair or anything. He has that hook up to this system that he got from some new AV company, it comes with a screen and projector, and the screen can be up to 65 feet. His is 10' diagonal. The projector is hooked up to a rack that can hold up to 36TB of drives, he currently has 8TB. You load your DVD's in and it copies them full quality and then downloads from their server all the metadata, description, cast, director, genre, poster, etc. When you want to watch something you can sort posters in a grid by genre, title, etc. Or you can select a movie and see the cast and then pull up everything else with that actor or by that director etc. And it's wired to a regular plasma in his bedroom, and in each of his two kids rooms, so everyone can be watching something at the same time. Then again, it was $11,000. But he seems to be quite happy with it. And no Handbrake or Mediafork settings to worry about, it takes it as is. One button and go.

roland..this is all cool and everything, but ya...way off topic :)

if anything, just makes us a bit jealous :)

Keebler
Mar 28, 2007, 07:00 PM
i'm going to hold off buying the apple tv until someone does come up with a solution for 5.1.

i think it's best we email apple's feedback site about it. if they hear people are balking at sales, they'll pull up their socks.

honestly, it may be petty, but i didn't spend some cash on my system to not listen to 5.1 or dts. some ppl don't say it makes a difference, but i like to hear arrows zipping by or swords clanking behind me from lord of the rings :)

and my wife wants to buy a pvr, but i'm telling her the appletv is better (even though i'd have to set the mac to record shows - not a problem with viditv).

Cheers,
keebler

kavika411
Mar 28, 2007, 09:01 PM
So, do we have a consensus? Can Apple TV do 5.1 with only a software upgrade, or can only a second generation Apple TV do 5.1?

I'm not trying to be annoying, it's just that this is the SINGLE QUESTION I must have answered before I drop $300 on this thing.

Thanks guys.

sycho
Mar 28, 2007, 09:09 PM
So, do we have a consensus? Can Apple TV do 5.1 with only a software upgrade, or can only a second generation Apple TV do 5.1?

I'm not trying to be annoying, it's just that this is the SINGLE QUESTION I must have answered before I drop $300 on this thing.

Thanks guys.

Second generation / revision for 5.1 on any content

software revision will allow dolby digital to be passed though

roland.g
Mar 28, 2007, 09:10 PM
I don't have the answer but I found this (http://www.roughlydrafted.com/RD/RDM.Tech.Q1.07/147048D8-D8B7-45E7-9A97-3CD5B4C2B75A.html) a very interesting read.

Diatribe
Mar 29, 2007, 09:24 AM
The options I see are:

1. AAC 5.1 is transcoded into AC3 (I don't know how technically feasible this is but I'd think not much)
2. AAC 5.1 is transcoded into PCM 5.1 and passed over the HDMI cable (the optical can only transport 2 channels in PCM afaik)
3. AAC decoder is included in a next-gen receiver
4. AC3 is included in the media file so it can be passed through (This WILL need a software upgrade as :apple:tv cannot currently do this)

It's tough to speculate but Apple will have to do something about surround support.
But to reiterate, none of the options (except 1 maybe) need a hardware upgrade, all are software upgrades. But whether or when Apple is gonna do it is the other question...

Diode
Mar 29, 2007, 09:58 AM
So, do we have a consensus? Can Apple TV do 5.1 with only a software upgrade, or can only a second generation Apple TV do 5.1?

I'm not trying to be annoying, it's just that this is the SINGLE QUESTION I must have answered before I drop $300 on this thing.

Thanks guys.



Software update. People have run VLC player on the ATV and were able to get AC3 audio to pass through to the toslink. It was stated eslewhere that at one point apple was considering doing passthrough with quicktime (remember atv runs quicktime for media playback). Currently quicktime converts any audio to PCM and if it doesnt have the codec's for the audio it can't do it.

The only legal way would either have apple pay Dolby Digital for the codec (not going to happen) or do passthrough.

The problem with passthrough is you need a device capable of decoding the signal (aka a 5.1 capable reciever) and apple wants a solution everyone can use (Hence the current delima).


*Hopefully* steve won't turn the ATV into another ipod and release a new one every 6 months ~.~

sycho
Mar 29, 2007, 10:20 AM
AAC 5.1 is a very real problem as no receiver decodes this yet.

I doubt that Apple will include AC3 streams as they are pretty big and would add a lot of file size.

There are plenty of receivers that decode AAC, but there are no devices that output AAC via SPDIF outside of Japan. And the bitrate for the 5.1 AAC on the HD trailers is around the same that is used on DVD, sometimes more.

The options I see are:

1. AAC 5.1 is transcoded into AC3 (I don't know how technically feasible this is but I'd think not much)Yeah, not much of a chance for this.

2. AAC 5.1 is transcoded into PCM 5.1 and passed over the HDMI cable (the optical can only transport 2 channels in PCM afaik)While this should have worked, I believe it can be confirmed that 5.1 via HDMI does not work, another poster in the other thread said that HDMI still only provided 2.0 PCM.
3. AAC decoder is included in a next-gen receiver Plausible, but I don't think there is any set spec for AAC via SPDIF. Oddly enough, my Yamaha RX-V650 has "AAC" on the vacuum display, weather it decodes it or not is another question, but it proves that atleast somewhere there are receivers with on board AAC decoding.
4. AC3 is included in the media file so it can be passed through (This WILL need a software upgrade as :apple:tv cannot currently do this) Apple will have to change the container, since MP4 doesn't play with AC3.

Diatribe
Mar 29, 2007, 10:34 AM
There are plenty of receivers that decode AAC, but there are no devices that output AAC via SPDIF outside of Japan. And the bitrate for the 5.1 AAC on the HD trailers is around the same that is used on DVD, sometimes more.

Yeah, not much of a chance for this.
While this should have worked, I believe it can be confirmed that 5.1 via HDMI does not work, another poster in the other thread said that HDMI still only provided 2.0 PCM. Plausible, but I don't think there is any set spec for AAC via SPDIF. Oddly enough, my Yamaha RX-V650 has "AAC" on the vacuum display, weather it decodes it or not is another question, but it proves that atleast somewhere there are receivers with on board AAC decoding. Apple will have to change the container, since MP4 doesn't play with AC3.

I don't know of any receiver being able to decode multi-channel AAC, can you give me link of one?
Besides, I don't know why option 2 wouldn't work over HDMI. It should if there is a multi-channel PCM conversion, which there isn't atm. Of course it doesn't right now because there is no conversion yet.

princealfie
Mar 29, 2007, 10:37 AM
It would require both I believe. The hardware would need to be able to decode the separate streams which the ATV cannot do at the present moment. 2.1 is good enough for most of my listening.

Diode
Mar 29, 2007, 11:52 AM
It would require both I believe. The hardware would need to be able to decode the separate streams which the ATV cannot do at the present moment. 2.1 is good enough for most of my listening.

Hardware IS ALREADY THERE . The apple tv has a Realtek ALC885 decoding chip.


Ten DAC channels support 16/20/24-bit PCM format for 7.1 sound playback, plus 2 channels of concurrent independent stereo sound output (multiple streaming) through the front panel output

All it needs is the proper SOFTWARE to support the features.

sycho
Mar 29, 2007, 12:01 PM
Hardware IS ALREADY THERE . The apple tv has a Realtek ALC885 decoding chip.



All it needs is the proper SOFTWARE to support the features.

OK, explain how the AppleTV is going to output when it only has SPDIF and a HDMI which is only outputting 2.0 PCM? :rolleyes:

Diatribe
Mar 29, 2007, 12:14 PM
OK, explain how the AppleTV is going to output when it only has SPDIF and a HDMI which is only outputting 2.0 PCM? :rolleyes:

You don't have to roll your eyes ;) Just because it is CURRENTLY only outputting 2.0 PCM doesn't mean it isn't capable of outputting multi-channel PCM.

Again, please stop spreading FUD with that know-it-all tone.

JonHimself
Mar 29, 2007, 12:23 PM
You don't have to roll your eyes ;) Just because it is CURRENTLY only outputting 2.0 PCM doesn't mean it isn't capable of outputting multi-channel PCM.

Again, please stop spreading FUD with that know-it-all tone.

I assume that apple TV has all the required certifications, and optical cables can obviously transfer 5.1 sound, so yeah, I agree... I don't see why it wouldn't be able to with a software update..

sycho
Mar 29, 2007, 12:25 PM
I assume that apple TV has all the required certifications, and optical cables can obviously transfer 5.1 sound, so yeah, I agree... I don't see why it wouldn't be able to with a software update..

Optical cables can only transfer compressed 5.1, not 5.1 PCM. The AppleTV does not have the hardware to convert AAC or PCM 5.1 in AC3. All iTunes bought content is AAC. Further more, there isn't any 5.1 content on iTunes besides the HD Trailers.

skrutzen
Mar 29, 2007, 05:31 PM
I just downloaded a DTS file and it played perfectly. My receiver switched to DTS and everything. Now how do I rip my dvds to include the DTS track? I am a fan of DTS and try to buy as many movies with that track. Lord Of the Rings has Discrete 6.1 and sounds amazing! I would love to be able to have those movies with DTS attached to it.

Peace
Mar 29, 2007, 05:43 PM
New Apple specific 5.1 codecs are on the way.;)

Trust me.Would I lie to you ? :)

netdog
Mar 29, 2007, 05:46 PM
New Apple specific 5.1 codecs are on the way.;)

Trust me.Would I lie to you ? :)

Given what some have done with the USB connection, I am really curious to see what plans Apple has for this port.

As for the codecs, I think you are certainly correct, and lie is such a strong word.

bankshot
Mar 29, 2007, 06:36 PM
I don't have the answer but I found this (http://www.roughlydrafted.com/RD/RDM.Tech.Q1.07/147048D8-D8B7-45E7-9A97-3CD5B4C2B75A.html) a very interesting read.

Nice find. I was going to suggest essentially what they say (and they say it in far more detail!), though it was only a stab in the dark since I don't have an AppleTV. Good to know that it's possible.

Essentially, you can play 5.1 audio by putting it inside a WAV, AIFF, or Apple Lossless container and sending it through a digital output to a home theater receiver that decodes the 5.1 bitstream. I know because I've done this with iTunes, using both my Macbook's digital out and the Airport Express digital out. Both worked flawlessly. I simply imported a DTS-encoded CD (The Police - Every Breath You Take (http://www.dts.com/entertainment/catalogue/music.php?upc=710215105321)) into iTunes as Apple Lossless and then played through the digital outputs. It was that simple.

One note of caution - as the above webpage also mentions, you can't play these files over your computer speakers or any analog output. The 5.1-encoded bitstream will be misinterpreted as 2-channel PCM audio, which will sound like VERY LOUD NOISE over analog speakers.

The missing link here seems to be whether this is possible with a QuickTime video file (actually they may address this in the webpage -- I just skimmed it). This would almost make the AppleTV look appealing if I could rip my DVDs and manually add the 5.1 audio track to the resulting QuickTime file. I'd still lose the DVD menus, but it'd almost be worth the savings over a Mac mini.

mollie319
Mar 30, 2007, 07:40 AM
Well,

I to think 5.1. is no issue on the AppleTV.

I've done the exact same thing as 'Bankshot' only with other files.
In the Apple Forums they discuss this:
http://discussions.apple.com/thread.jspa?threadID=901601&tstart=0

I've downloaded a file, and put it in iTunes.
it's an DTS 5.1 96/24 sound file (.wav)
I synced the file on my AppleTV, play the file
and my receiver (Yamaha) outputs on the display:

DTS 5.1 channel sound

All the speakers lit up:
front - left
Center
front - right

rear right
rear left
Subwoofer

When I play an stereo tune, it simple display these speakers:
front - left
front - right

So, that means that the AppleTV can output 5.1 channel sound.

I've used an HDMI cable from the AppleTV to my Receiver.
Works flawlesy

Marcel

netdog
Mar 30, 2007, 07:43 AM
AppleTV is looking better and better. Again, like iPhone, the key may be in its own flexibility as a little Mac as opposed to a piece of hardware with an embedded system .

princealfie
Mar 30, 2007, 08:19 AM
Hardware IS ALREADY THERE . The apple tv has a Realtek ALC885 decoding chip.



All it needs is the proper SOFTWARE to support the features.

But can the chip have the processor speed to run the 5 channels separately?

pengu
Mar 30, 2007, 08:33 AM
Well,

I to think 5.1. is no issue on the AppleTV.

I've done the exact same thing as 'Bankshot' only with other files.
In the Apple Forums they discuss this:
http://discussions.apple.com/thread.jspa?threadID=901601&tstart=0

I've downloaded a file, and put it in iTunes.
it's an DTS 5.1 96/24 sound file (.wav)
I synced the file on my AppleTV, play the file
and my receiver (Yamaha) outputs on the display:

DTS 5.1 channel sound

All the speakers lit up:
front - left
Center
front - right

rear right
rear left
Subwoofer

When I play an stereo tune, it simple display these speakers:
front - left
front - right

So, that means that the AppleTV can output 5.1 channel sound.

I've used an HDMI cable from the AppleTV to my Receiver.
Works flawlesy

Marcel

good to hear, but not very suprising really. As you said, itunes/quicktime will pass the ac3/dts in the same file over optical out, and ?TV is running osx, no doubt with quicktime to playback media files.. i will see if i can build a .mov file or a .mp4 file with AC3/DTS and video content. if i succeed and it plays in QT, i'll put the file online for someone to check on an ?TV if someone is willing.

pengu
Mar 30, 2007, 10:42 AM
well good news and bad news.

a quicktime movie with video and the audio from an AC3/DTS encoded wav file does play, and QT does send the encoded stream to my z5500's decoder.

however. the problem is. it seems you need Dolby Encoder software to create a WAV/AIFF file with 5.1 encoded content. the cheapest i saw was $US249.

i tried all manner of combinations (using some ac3 i ripped from a 007 dvd) but i could not produce a file that QT would pass the ac3 stream to the optical port.


so basically. we CAN have 5.1 audio in a movie playing with ?TV, but we have no way to actually encode the 5.1 audio into the correct format, so the only audio we can use is what's available online (ie, demos of AC3/WAV files, or DTS files from Radio Sweden.. neither of which seem particularly ideal :rolleyes: )

Diatribe
Mar 30, 2007, 11:23 AM
well good news and bad news.

a quicktime movie with video and the audio from an AC3/DTS encoded wav file does play, and QT does send the encoded stream to my z5500's decoder.

however. the problem is. it seems you need Dolby Encoder software to create a WAV/AIFF file with 5.1 encoded content. the cheapest i saw was $US249.

i tried all manner of combinations (using some ac3 i ripped from a 007 dvd) but i could not produce a file that QT would pass the ac3 stream to the optical port.


so basically. we CAN have 5.1 audio in a movie playing with ?TV, but we have no way to actually encode the 5.1 audio into the correct format, so the only audio we can use is what's available online (ie, demos of AC3/WAV files, or DTS files from Radio Sweden.. neither of which seem particularly ideal :rolleyes: )

Thanks for the tests. I guess we will have to wait and see what Apple does. :cool:

sycho
Mar 30, 2007, 02:18 PM
Well,

I to think 5.1. is no issue on the AppleTV.

I've done the exact same thing as 'Bankshot' only with other files.
In the Apple Forums they discuss this:
http://discussions.apple.com/thread.jspa?threadID=901601&tstart=0

I've downloaded a file, and put it in iTunes.
it's an DTS 5.1 96/24 sound file (.wav)
I synced the file on my AppleTV, play the file
and my receiver (Yamaha) outputs on the display:

DTS 5.1 channel sound

All the speakers lit up:
front - left
Center
front - right

rear right
rear left
Subwoofer

When I play an stereo tune, it simple display these speakers:
front - left
front - right

So, that means that the AppleTV can output 5.1 channel sound.

I've used an HDMI cable from the AppleTV to my Receiver.
Works flawlesy

Marcel

The problem with these kinda of encoding is that people using regular stereo connections are only going to hear static. I ask you this, would you want a CD encoded like this where you can only play it on a system that has a digital connection to the receiver? That mean no car CD players, no boomboxes, no typical CD player set up. That is why this is not a great option.

pengu
Mar 30, 2007, 10:22 PM
The problem with these kinda of encoding is that people using regular stereo connections are only going to hear static. I ask you this, would you want a CD encoded like this where you can only play it on a system that has a digital connection to the receiver? That mean no car CD players, no boomboxes, no typical CD player set up. That is why this is not a great option.

its a great option for anyone with a Dolby/DTS decoder connected to their ?TV. if you dont have one, don't encode the audio. its not a solution apple is likely to offer, its a way for those of us who want to add our own movies to the ?TV.

i'd love if apple added Dolby Digital Live (takes a sound the "system" is playing with more then 2 channel, encodes it to Dolby Digital 5.1 (maybe even DD EX?) and sents it out the optical/coax port in real time. this would mean we could have AAC5.1 in mp4 movies, and the ?TV would send the required AC3 encoded stream to the decoder. if they did that, i'd be hoping something simmilar was available for the computer lineup too..

mollie319
Mar 31, 2007, 12:07 AM
The problem with these kinda of encoding is that people using regular stereo connections are only going to hear static. I ask you this, would you want a CD encoded like this where you can only play it on a system that has a digital connection to the receiver? That mean no car CD players, no boomboxes, no typical CD player set up. That is why this is not a great option.

I don't know.
But the discussion was about AppleTV and 5.1 surround sound.
People, like yourself, seems 2 know everything about the AppleTV, even that it doesn't output 5.1 sound.

I say it does. My simple test proves that. Other tests prove that too.
Whatever other people do, with car stereo's I don't care.
The AppleTV CAN output 5.1 surround sound.

And I think Apple wouldn't be that stupid to put it on the market and have no 5.1 sound.

Marcel

Flynnstone
Mar 31, 2007, 09:26 AM
It seems like we need a Wiki about what can go into a receiver (audio).

I read that the AppleTV can do DTS pass through.
Is there an easy way to rip my DVD with something like Handbrake and get the DTS soundtrack?
Is there (free, lowcost) software the can transcode Dolby Digital or Dolby prologic (or other) to another format that the AppleTv can pass through? Such as DTS?
Many (most?) surround sound receivers have a digital input (Toslink or coax).

If I read all this audio about the AppleTV. It can do surround via it's two audio output channels with a receiver that does Dolby Pro logic (not Dolby Digital) or it can do surround via DTS (others?) via Toslink and pass through.

kavika411
Mar 31, 2007, 04:56 PM
Thank you to everyone who has attempted to answer the question in my orignal post. Based upon your thorough, well thought out, completely contradicting answers, I make the following declaration to Apple:

Neither I nor a small legion of Apple/iTunes devotees will, no matter how much we want to, buy an Apple TV until you give us even a clue to the most rudimentary of questions - WHAT PREPARATIONS HAVE YOU MADE TO PLAY 5.1 SURROUND FOR THE COMMON VIEWER/LISTENER?

localoid
Mar 31, 2007, 11:08 PM
Thank you to everyone who has attempted to answer the question in my orignal post. Based upon your thorough, well thought out, completely contradicting answers, I make the following declaration to Apple:

All of the threads here about "teh 5.1" remind me of the "are Quadraphonic LP Records (http://www25.brinkster.com/ranmath/pages01/frauds.htm) real or a fraud" discussions circa the early-1970's... :p

I don't think there's been that many, if any, "completely contradicting answers" in this thread -- the differences of opinions have centered around the "details" and pros and cons of using such methods; for example, the "details" regarding raw-streaming of a previously encoded DD sound file to the Apple TV: It's said to work, but for anyone without a receiver w/AC-3 decoder it will sound like very loud static. Yadda, yadda, yadda...

But I think it's important to note that all the (different) opinions and reporting of various findings have made the thread that much more valuable! ;)


Neither I nor a small legion of Apple/iTunes devotees will, no matter how much we want to, buy an Apple TV until you give us even a clue to the most rudimentary of questions - WHAT PREPARATIONS HAVE YOU MADE TO PLAY 5.1 SURROUND FOR THE COMMON VIEWER/LISTENER?

Apple isn't advertising :apple: tv as being 5.1-ready... But I'd think it's logical to assume that Apple is probably among the best "prepared" in the industry in regards to anything "content" related, esp. content that has anything to do with making a profit is concerned. After all, its iTunes Store is the Internet's #1 source of (legal) downloads of paid content. However, since Apple rarely comments in detail on future plans, I doubt you'll hear any "official" comment from Apple in advance of a product offering... :p

Meanwhile... the off-the-shelf solution to "teh 5.1" problem that Hollywood wants every "consumer" to use is centered around playback of content via optical discs, e.g., Hollywood wants "protection" on such content -- DRM, et al. When any kind of recording or copying of content becomes "easy" (for Joe Average Public to do)... Hollywood has nightmares about dollar bills spouting wings and flying away.

Remember the recently published Steve Jobs' open letter about DRM and music? :p

Mossman
Apr 1, 2007, 04:05 AM
As Marcel has done, I downloaded a DTS WAV file and put it into iTunes and it played perfectly - yes, I have got the :apple: TV hooked up to a Yamaha 5.1 amp, and then into Miller and Kriesel Speakers :cool:

GregA
Apr 1, 2007, 07:59 AM
Essentially, you can play 5.1 audio by putting it inside a WAV, AIFF, or Apple Lossless container and sending it through a digital output to a home theater receiver that decodes the 5.1 bitstream. I know because I've done this with iTunes, using both my Macbook's digital out and the Airport Express digital out. Both worked flawlessly. I simply imported a DTS-encoded CD (The Police - Every Breath You Take (http://www.dts.com/entertainment/catalogue/music.php?upc=710215105321)) into iTunes as Apple Lossless and then played through the digital outputs. It was that simple.

I assume that's what these files are?
http://hdonappletv.webhop.net/

I'll have to have a play tomorrow when visiting my parents.

pickerin
Apr 1, 2007, 08:56 AM
OK, explain how the AppleTV is going to output when it only has SPDIF and a HDMI which is only outputting 2.0 PCM? :rolleyes:

Easy. It has a TOSlink, Optical Digital Audio. No limitations in the hardware.

In fact, my AppleTV is CURRENTLY OUTPUTTING DTS 5.1 AUDIO, with no modifications at all.

See my post here (http://forums.macrumors.com/showthread.php?t=289559&page=2) on the Forums for the details. However, if you have an AppleTV, iTunes, and time to download a 60 or 80MB DTS 5.1 reference file. Then you too can prove to yourself that there is nothing stopping 5.1 audio from playing on the AppleTV *unmodded*. It's all about the content baby!

And...the next release of Handbrake will properly encode the 6-channel audio so that our DVD rips have 5.1 and will play it on the AppleTV.

There is a great article on Digg that you should check out, I didn't post it, but I'd like people to Digg it up so we can once and for all settle this discussion and get more of these into people's hands.

Here's the article on Digg: Ten Myths of the Apple TV 5.1 Audio (http://digg.com/apple/Ten_Myths_of_the_Apple_TV_5_1_Audio)

-Rob

MacCanuck
Apr 1, 2007, 08:13 PM
WRONG!!

It is not a software issue people, it is a HARDWARE limitation.

That is the pretty much the same thing in the MacBook, iMac, MacMinis and Mac Pros. All of those only output stereo PCM.

I have played DVD's on my Mac Mini that produce 5.1 surround to my receiver. I had to turn on a Digitial Output in the DVD player app, but it worked very well. So I doubt it's a hardware issue.

MacCanuck
Apr 1, 2007, 08:26 PM
Easy. It has a TOSlink, Optical Digital Audio. No limitations in the hardware.

In fact, my AppleTV is CURRENTLY OUTPUTTING DTS 5.1 AUDIO, with no modifications at all.

See my post here (http://forums.macrumors.com/showthread.php?t=289559&page=2) on the Forums for the details. However, if you have an AppleTV, iTunes, and time to download a 60 or 80MB DTS 5.1 reference file. Then you too can prove to yourself that there is nothing stopping 5.1 audio from playing on the AppleTV *unmodded*. It's all about the content baby!

And...the next release of Handbrake will properly encode the 6-channel audio so that our DVD rips have 5.1 and will play it on the AppleTV.

There is a great article on Digg that you should check out, I didn't post it, but I'd like people to Digg it up so we can once and for all settle this discussion and get more of these into people's hands.

Here's the article on Digg: Ten Myths of the Apple TV 5.1 Audio (http://digg.com/apple/Ten_Myths_of_the_Apple_TV_5_1_Audio)

-Rob
Thanks for the link. I am playing some of the sample DTS 5.1 WAV files right now on my AppleTV. My receiver is decoding it perfectly. So I suppose it's a matter of encoding the content with a compressed enough version and then upconverting to DTS or DolbyDigital.

Now if only I could buy movies online up here in Canada! :(

backstagetv
Jun 16, 2007, 02:39 AM
So, now i know soon HandBrake could help me convert a DVD straight to something my AppleTV plays and with support of 5.1 sound, cool! ;)

Now, how about i don't have the source DVD, but an AC3-DivX .avi rip of it? :o :rolleyes:
Is there still a way to convert this into something my AppleTV will play and still keep/support the 5.1?
Or is that just too much asked? :eek: :)

Fyi, my AppleTV connects to a standard AV-Receiver with built-in AC3-DTS Decoder...

I'd really appreciate if anyone could shed some light on this, as i've been searching for some time now on how to do this...
Thanks a lot.

BSTV

Edandlindz28
Jun 16, 2007, 04:07 AM
So, now i know soon HandBrake could help me convert a DVD straight to something my AppleTV plays and with support of 5.1 sound, cool! ;)

Now, how about i don't have the source DVD, but an AC3-DivX .avi rip of it? :o :rolleyes:
Is there still a way to convert this into something my AppleTV will play and still keep/support the 5.1?
Or is that just too much asked? :eek: :)

Fyi, my AppleTV connects to a standard AV-Receiver with built-in AC3-DTS Decoder...

I'd really appreciate if anyone could shed some light on this, as i've been searching for some time now on how to do this...
Thanks a lot.

BSTV

Don't know if this would work, but have you looked at the MPEG player by squared5. they have away to convert .avi to mp4, but I can't remember the audio output. Or drag the .avi to iMovie, but I don't know if that will export with 5.1.

bmb012
Jun 16, 2007, 08:04 PM
There is no AC3 content on iTunes, only AAC:rolleyes: The AppleTV can not convert AAC to AC3, because of a hardware limitation. Go read the first reply to this thread. It is funny, people hear seem to ignore the truth big time when they don't want that answer.

Um... no? The AppleTV can't output ac3 because Apple hasn't licensed it from Doby. The original xBox could encode 5.1 ac3. You're trying to tell me that the AppleTV's super-efficient, low power Dothan is weaker than xBox's ghetto rigged Pentium 3...? Yeah, okay... And an optical output is an optical output. The Airport express can output 5.1, if it's playing a wav file that closely mimics actual ac3 content.

backstagetv
Jun 17, 2007, 03:21 AM
Don't know if this would work, but have you looked at the MPEG player by squared5. they have away to convert .avi to mp4, but I can't remember the audio output. Or drag the .avi to iMovie, but I don't know if that will export with 5.1.

thx for that. i'll try but doubt it will. :/ I've read on another forum i should try VisualHub too.

Frazzle
Jun 23, 2007, 05:28 PM
Maybe it's good to start with the basics again:

To get multichannel sound into content files, you have basically 2 options:

Encode the channels into a proprietary compressed data stream (AC3, DTS, AAC, WMA) and let the player hardware or software deal with it
Provide each channel in a separate uncompressed stream - which will generate huge files but has very high quality (HD DVD and BluRay can and do use this option)


So far so good. Next you will need to get all channels in the content out of your player device. Here you have 3 options:

Use a digital connection to carry a compressed data stream (AC3, DTS - AAC and WMA output is rare) with all the channels encoded into the stream
Use a digital HDMI connection to carry each channel in a separate uncompressed stream or carry all channels in a compressed data stream (same as #1)
Provide one mono analogue connection for each channel


To get multichannel sound into a receiver or amplifier, the same 3 options are available:

Digital input of compressed data stream with optical or coaxial cable
Digital HDMI connection, separate uncompressed streams or same compressed stream as #1
One mono analogue cable for each channel


This is all very straightforward, especially if you have a compressed stream in your content and want to carry it to the receiver with no alterations. Watching DVD's on a home theater is just that - the receiver decodes a data stream that comes straight from the DVD.

The fun begins when you want or need to convert separate channels into a compressed stream or vice versa. This will always mean encoding or decoding and licensing issues.

With these basics in mind, you can easily see where the possibilities and limitations are for the Apple TV:

Carrying a compressed AC3 or DTS stream that's present in the content over the optical digital output to the receiver is easy. It's just hauling bits from one end to the other. Playing a DTS encoded WAV file proves that.
Carrying a compressed AC3 or DTS stream that's present in the content over HDMI depends on whether Apple fully wired its HDMI port and can route the bitstream to that port. If yes, then it's no problem.
Outputting uncompressed streams over HDMI requires either content with separate streams (unlikely) or content that the Apple TV can decode (AAC should be easy). This puts a strain on the CPU to decode it.
Outputting a compressed stream in either AC3 or DTS format from uncompressed or differently encoded content (AAC) requires on-the-fly encoding which will need a license and is CPU intensive. Separate hardware is usually required.
Because the Apple TV has only 2 stereo analogue ports, hooking it up over analogue cable is limited to stereo.


The ALC885 chip in the Apple TV can output 7.1 channels, but only if it gets the connectors to do it. On the AppleTV multichannel analogue is impossible due to the lack of connectors, so the only option for uncompressed multichannel output here is the HDMI port. On-the-fly encoding of a compressed stream seems unlikely to me.

Apple usually pushes standards to their limit, so I wouldn't be surprised if the AppleTV can actually run 8 (7.1) PCM streams over a well-implemented HDMI port. But they will need to decode any compressed format first and you will need a very modern receiver with HDMI inputs to listen to it.

The answer has to come from Apple, as we have no way of knowing what the HDMI port on the Apple TV is actually capable of. Do they list adherence to the HDMI spec anywhere (1.1, 1.2, 1.3)?

The only other option is the USB port. Apple could make a simple USB dongle that provides the necessary analogue outputs, just like the many dongles you can already buy for PC use.

theLimit
Jun 23, 2007, 09:43 PM
thx for that. i'll try but doubt it will. :/ I've read on another forum i should try VisualHub too.

Yeah, under the "Advanced" tab in VisualHub is the option to copy the original audio track.

defsquad
Jul 7, 2007, 02:59 PM
so, knowing all of this about the 5.1 channel back and forth; i think it's safe to say that if you hook the appletv in it's current version to a capable receiver using toslink (optical out/in), then you're golden and will get that 5.1 surround sound fun. provided the source content contains the audio stream as 5.1.

yay, i was going to get an old carpc (windows based) or setup linuxmce/mythtv to act as my htpc (really only using it to stream content from my macbook pro and attached 500gig drive), but instead, i think i'll go with the appletv since i really don't care to have 2 repositories of data to manage. couple this knowledge with the other, ahem, "hacks" available for the appletv, it looks to be a pretty solid choice (that is if you don't mind 720p being the highest video output).

i want to personally thank the OP and everyone that commented with personally helping me make my buying decision even easier.

benpatient
Jul 26, 2007, 02:01 PM
um...MP4 plays just fine with AC3 and DTS.

For your information, I've got an entire playlist of DTS-encoded Apple Lossless .mp4 files sitting in my iTunes folder, connected with optical out to my receiver. These came mostly from DTS 5.1 Cds that were mildly popular back when DVD-A and SACD first showed up.

itunes doesn't molest the files if you turn the software volume to 100% and turn off sound check/cross fade,etc. I listen to discreet 5.1 music straight from itunes via passthrough. AC3-encoded .mp4 audio files also work.

the aTV doesn't allow the passthrough. Which means that it is molesting the signal somewhere.

hacking efforts have shown that it's a software thing, not hardware.

apple could easily wrap a lossless AC3-encoded ALC stream into their video downloads. It would increase the file size, but not THAT much. AC3 can be pretty compressed as it is...like 200-300kb/s.

iJon
Jul 27, 2007, 02:48 AM
For everyone's AC3 woes, I think this should work.

You would have to hack your AppleTV to place this file in the proper folder, but once done should handle Dolby D EX and more. I use this on my MacBook Pro in conjunction with VLC to play all kinds of formats flawlessly.

http://trac.cod3r.com/a52codec/

jon

kavika411
Jan 16, 2008, 08:31 AM
Only took eight months to get an official answer. :eek::p