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Does true, easy 5.1 require a software or hardware update?

Discussion in 'Apple TV and Home Theater' started by kavika411, Mar 28, 2007.

  1. macrumors 6502a


    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.
  2. macrumors 6502a


    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.).
  3. macrumors 603


  4. macrumors 68000


    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.
  5. macrumors 601


    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.
  6. macrumors 6502a



    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.
  7. macrumors 601


    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!
  8. macrumors 6502a


    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.
  9. macrumors 68000


    Right, but Diatribe is only correcting your statement about the inablity of Mac computers to do so. (I think)
  10. macrumors 601


    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.
  11. macrumors 603


    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.
  12. macrumors 68000


    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.
  13. macrumors 68030

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

    if anything, just makes us a bit jealous :)
  14. macrumors 68030

    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).

  15. macrumors 6502a


    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.
  16. macrumors 6502a


    Second generation / revision for 5.1 on any content

    software revision will allow dolby digital to be passed though
  17. macrumors 603


    I don't have the answer but I found this a very interesting read.
  18. macrumors 601


    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...
  19. macrumors 68020



    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 ~.~
  20. macrumors 6502a


    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.
  21. macrumors 601


    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.
  22. macrumors 68030


    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.
  23. macrumors 68020


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

    All it needs is the proper SOFTWARE to support the features.
  24. macrumors 6502a


    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:
  25. macrumors 601


    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.

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