Originally Posted by stompy
Thanks Jeff, makes perfect sense.
Originally Posted by JeffDM
I know DTS has been using CDs and PCM streams to transport its data, but for modern files, it's kind of a hack. It's kind of stupid too, given how DTS is 765 kbps or 1.5Mbps for just audio, it's just not realistic for downloaded files. Apple sells TV shows that are encoded at 1.5Mbps for the combined video and audio streams.
Right now, there is no option in Quicktime to encode PCM or DTS into a H.264 stream, which is why I said that there's little to no infrastructure for it, there's no content that's like that and no apparent way to make that content. As that Roughly Drafted site said, there is AAC 5.1, but I don't remember seeing any receivers that will decode that. AppleTV can't output decoded AAC 5.1 either.
Originally Posted by stompy
According to the link quoted by Sport73, AppleTV does DTS, but not DD. jeffdm's point is, until you can rip a DVD to some format with 5.1 sound that the AppleTV will play back in 5.1
, it's all academic. (If it is possible, without hacks, please correct me.)http://www.thismuchiknow.co.uk/?p=34
This is a bit of a quagmire, intellectually.
I'll give it a shot. I woke up at 5.30am this morning thinking about this stuff, it's 7.30am and my neighbour is frying up what smells like mmm... bacon... Dammit! I need more sleep so I'll try and be brief.
1. I think a lot of you have made valid points that the highest quality surround we can get at this stage is DTS and AC3.
2. DTS and AC3 bitstreams are unnecessarily big for the modern Intarweb standards, etc.
3. I tend to agree more with RoughlyDrafted link than ThisMuchIKnow.
4. DolbyDigital I and II decoding of the stereo-matrix AppleTV output of AAC 2-channel or 5.1-channel .mp4, .m4v, .mov files is very acceptable for a lot of consumers and the mainstream with these 5.1 or 7.1 amp and speaker setups.
5. I strongly believe AAC 5.1 in a MP4, M4V container is the way to go for the future. Rev B or C of AppleTV, if and when we get iTunes Store 720p HDTV material, I agree, would be good to have AAC 5.1-encoded files, with AppleTV outputting AC3 (not DTS*) to 5.1 and 7.1 amp/speaker setups.
6. DVD and other sources of AC3 and DTS when played back from Macs are not an issue with digital optical out into your digital optical in of your AC3 and DTS capable 5.1/ 7.1 amp/speaker setups. Otherwise the messier sound card - to - speaker (no discrete amp) setup.
7. If you are ripping DVDs, you will want to do a MP4 container with H.264 video and AAC 5.1 audio [Besweet and NeroAudio as main tools]. Doom9.org has all you need to know... It is predominantly PC-based but it is more important since we are talking about iTunes and Quicktime and iPod and AppleTV, which is, predominantly PC-user-base. I feel this enthusiast PC-user-base audience is the most likely users of AppleTV that will want quality DVD-rips with 5.1 surround "maintained" to some level, with the convenience of not having to physically carry around or slot in discs, etc. (That's why they're ripping DVDs, they're encoding geeks, like digital assets on their computers, DVD-enthusiasts that want to preserve their "master prints" of movies in the original pristine quality, plus some want to pirate out their encodes)... As one of the Doom9 forum members have in their signature, "I encode therefore I am". I pulled a nice rip of Matrix-LobbyScene and Matrix-Morpheus.vs.Neo into mp4-h.264-aac(stereo) rips that's playable and streamable off iTunes/Quicktime, there's a real sense of satisfaction...Heh... Did it in Windows via Parallels. Hella complex, I can't repeat it now unless I have like 10 browser tabs open for all the tools and techniques. For Mac, Handbrake or FFMPEGx, should soon, if not already, have AAC 5.1 encoded audio for DVD-rips. If what RoughlyDrafted is saying, this is a good intermediate step for AppleTV surround sound on our current convergence journey.
*AC3 is Dolby Digital which is the more common standard with the very famous "Dolby" name. While I personally *love* DTS on DVDs (and believe it is superior to AC3), globally, AC3 (Dolby Digital) is very much more mainstream and "good enough" for AAC 5.1 - encoded, AC3-output-transcoded - setup for AppleTV rev B or C with 720p HDTV H.264 content.