DTS-HD passthru w/Apple TV 2?

[Scott R]

I was looking at the notes for the recent daily builds and saw mention of adding DTS-HD support to MP4 files. Should that work with the Apple TV 2? And assuming that I also include a mixdown track, should those files still play without issue on an iPhone 4 or iPad? Obviously, I can test this out myself, but I won't be able to do so till the weekend, so I thought I'd post about it now, since it seems like it could be a popular update for some of us if it works.

Oh, and if the above will work, is it correct to assume that Dolby TrueHD passthru is also supported?

[Deleted User 11865]

It won't work with anything but players using a very recent version FFmpeg/Libav (late June or newer).

[kiran_mk2]

I don't have my ATV to hand at the moment. If we were to encode a file with audio track 1 as AAC stereo, track 2 as AC3 and track 3 as DTS and feed it into iTunes would the various Apple devices just not play it at all or would they play the AAC and AC3 tracks?

[Deleted User 11865]

It won't play it at all ("invalid sample description" error or similar)…

[Scott R]

I've been out of town, so I'm just now getting around to replying again...thanks for the info (even if I'm not happy about the answer).

[kiran_mk2]

Just a quick bump - I've finally gotten around to converting a bit of DTS film - m4v file has AAC, AC3, DTS and AAC commentary track. VLC (v 1.1.12) plays all except the DTS track (as expected). The file is accepted and playable in iTunes (again, the DTS option is not available, but it plays the other tracks) and, as anticipated the file doesn't play on a 1st gen ATV. However, it does sync and play on my 3GS running iOS 5 - although, again the DTS track isn't recognised. On this evidence I'm guessing it would play on an ATV2 (which I don't have to test).

In Subler, the DTS track is detected as Stereo, AAC 0-channel track.

Still on the fence about whether to go ahead and encode all my DTS films this way and just wait until the situation develops a bit more (I'm too anal to just go with the AC-3 track...)

[Kip]

I don't have an AppleTV, but I can almost guarantee it will not play any type of DTS track. Apple does not include DTS in any of the movies they sell, so I'm sure they don't have the licensing to decode DTS on their device.

I myself would like to keep DTS audio on my mp4's as well and I have debated over using mkvs to keep the original audio, but I prefer mp4s since they can play on a variety of devices. I have converted DTS to AC3 and it still sounded great....but I only have a 3.1 soundbar for my sound system. I have yet to try it on a 5.1 system to see if I can tell the difference between that and the original DTS track. The only positive in this that I've recently found is that subler allows you to remove a track from an mp4 if needed, without re-encoding. I think this would be great in your case because you can include the required tracks for itunes/iphone/apple tv/etc (AAC,AC3) and for a third track you can include DTS. IF at some point some media player can start recognizing DTS in mp4s (if they haven't already)...then you're set. If not...then you delete the DTS track using subler and now you've saved some space.

I'd like to think Apple would start using DTS in the future...because it seems the majority of blurays out there use DTS (at least the ones I've been getting), but there's no guarantee Apple will do that.

[TedJ]

I'd like to think Apple would start using DTS in the future...because it seems the majority of blurays out there use DTS (at least the ones I've been getting), but there's no guarantee Apple will do that.

Not likely. Although the majority of studio BD releases have moved to DTS-HD Master Audio, Apple has no vested interest in supporting it... They'd much rather you purchased your movies from iTMS. Also, DTS-HD is too high bitrate to be really suited to streaming or downloads; in this case AC3 gives 75% of the bang for much less space.

[Kip]

Not likely. Although the majority of studio BD releases have moved to DTS-HD Master Audio, Apple has no vested interest in supporting it... They'd much rather you purchased your movies from iTMS. Also, DTS-HD is too high bitrate to be really suited to streaming or downloads; in this case AC3 gives 75% of the bang for much less space.

Oh I wasn't talking DTS-HD...I just meant DTS (although I realize the original poster was talking about DTS-HD). I know the size difference is huge and HD audio will likely not be used on anything but blurays for years to come...but regular DTS vs AC3 isn't too much of a difference in size. But yes I also think it's unlikely Apple will ever include anything other than DD. With the increase in streaming media and internet downloads and decrease in blu rays and DVDS I wonder what is going to happen to HD audio (both True HD and DTS HD-MA) in the future...but that's a question for another topic.

[TedJ]

They may go the same way as DVD-Audio and Super Audio CD (SACD).

[kiran_mk2]

Another quick bump - the new update of VLC 2.0.2 correctly plays back DTS in mp4

[GregiBoy]

Another suggestion is to forget the brain dead Apple TV's as an option and when you are ready to go the media player route, buy one that will play everything.