Apple TV and 5.1 support - some definitive answers

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nightstrm
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Post by nightstrm »

Right the .1 info is completely ignored. If you are still getting output from your subwoofer, it is because it was present in the other channel information.
dynaflash
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Post by dynaflash »

.... or because you amp is set to direct anything below a certain frequency to the subwoofer (like my onkyo can do).
doctorSpoc
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Post by doctorSpoc »

nightstrm wrote:Right the .1 info is completely ignored. If you are still getting output from your subwoofer, it is because it was present in the other channel information.
well i think technically the .1 channel it's ignored by HB, but not by the receiver... the receiver would use it if it was there, it's just not there because HB didn't encode it.

my receiver also will take frequencies below a certain level and play them through the sub and if you set the other speakers to "small" it will crossover at an even higher frequency.. my sub also has it's own crossover so you could take the left and right channels and extract from that as well.
nightstrm
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Post by nightstrm »

doctorSpoc wrote:
nightstrm wrote:Right the .1 info is completely ignored. If you are still getting output from your subwoofer, it is because it was present in the other channel information.
well i think technically the .1 channel it's ignored by HB, but not by the receiver... the receiver would use it if it was there, it's just not there because HB didn't encode it.

my receiver also will take frequencies below a certain level and play them through the sub and if you set the other speakers to "small" it will crossover at an even higher frequency.. my sub also has it's own crossover so you could take the left and right channels and extract from that as well.
Yes, that is exactly what I said... Handbrake ignores the .1 information when remixing to DPL2.
Deleted User 5579

Re: Apple TV and 5.1 support - some definitive answers

Post by Deleted User 5579 »

Read this thread and did the search for both wiki and HB forums. What I didn't see mentioned is that with the new DPLIIx available in just about all modern receivers today. Wouldn't it be better to encode the audio as "Stereo" rather than Dolby Surround or Pro Logic II?

Because according to wiki and Dolby FAQ the new DPLIIx can up-convert stereo, DPL and DPLII to 6.1 or 7.1 surround sound.

From what I have read here so far, HB will ignore .1 when encoding to DPL or DPLII. So when fed to a DPLIIx capable receiver, the LF are not as dramatic when up-converted from a HB DPL/II signal.

But does that ignore .1 rule apply to stereo also?

If HB doesn't ignore .1 when encoding in stereo format, then receivers with DPLIIx can up-convert it to 6.1 or 7.1 and have a more fuller LFE signal?
rhester
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Re: Apple TV and 5.1 support - some definitive answers

Post by rhester »

You can't up-convert what isn't there. If you encode as stereo, you lose the channel separation in the rears, period. DPL II can "upconvert" to, to a degree, but the result isn't valid.

What you're talking about is where the upconverter basically guesses at what should be in the rears, not at all unlike DPL II in music mode.

Bottom line: This is a horrible idea. We didn't spend all that time getting DPL II working because we thought it was a waste of time.

Rodney
Deleted User 5579

Re: Apple TV and 5.1 support - some definitive answers

Post by Deleted User 5579 »

Oh I see. DPLIIx can only do so much, so feeding it Stereo only would lose even more channel separation vs DPLII encoding. So the choice is lose the .1 to DPLII encoding, but the receiver will give a much clearer separation but a loss on the LFE. Encoding in Stereo, HB feeds the .1 into your Stereo encoding, but your receiver will lose channel separation, but the receiver can bring out a more fuller bass signal.

The loss in bass isn't so bad when encoding to DPLII for standard DD 5.1, but thanks for clarifying that info, as Dolby and Wiki marketing speak makes it sound like its capable of doing magic. :wink:

I did notice that when you do encode a DVD that had DDEX flags to DPLII, the bass loss is much more dramatic than standard DD 5.1. I experimented on Shoot em Up which has DD EX and you can tell clearly on this one compared to most DVDs with standard 5.1 the dramatic bass loss. Fortunately most DVDs are not EX encoded.
MichaelLAX

Re: Apple TV and 5.1 support - some definitive answers

Post by MichaelLAX »

We're all still waiting to see how Apple implements 5.1 in their new Take 2 software for the Apple TV...
flybynight
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Re: Apple TV and 5.1 support - some definitive answers

Post by flybynight »

Agreed that we are all eagerly anticipating to see how Apple does it in the "Take 2" software.
But, in regard to DPLII, is it really throwing out the ".1" LFE? Wouldn't there be a way to put that back into the stereo channels? Most receivers will just filter out the low frequencies and re-direct them to the sub anyway.
rhester
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Re: Apple TV and 5.1 support - some definitive answers

Post by rhester »

flybynight wrote:But, in regard to DPLII, is it really throwing out the ".1" LFE?
HandBrake is, yes. So are all other quality DPL II encoders.
flybynight wrote:Wouldn't there be a way to put that back into the stereo channels?
Of course - but then you run the risk that the LFE data is duplicated in the mains (and it nearly always is) and you will thus end up playing both in-phase and out-of-phase at the same time (and this is Not Good(TM)).
flybynight wrote:Most receivers will just filter out the low frequencies and re-direct them to the sub anyway.
And that's precisely why we don't encode LFE, at Dolby's recommendation.

Rodney
MichaelLAX

Re: Apple TV and 5.1 support - some definitive answers

Post by MichaelLAX »

rhester wrote:...Of course - but then you run the risk that the LFE data is duplicated in the mains (and it nearly always is) and you will thus end up playing both in-phase and out-of-phase at the same time (and this is Not Good(TM))...
BTW: Whose trademark is Not Good?
agata
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Re: Apple TV and 5.1 support - some definitive answers

Post by agata »

Ok- I know this is a handbrake forum, but maybe this will help with the overall efforts.

First off, this will allow you to play on a DD receiver ONLY. If you try to play on your laptop, you get static... so that said.

1) Demux with MPEG Streamclip to M2V and AC3.
2) Copy AC3 to windows machine to use BeSweet to convert to DD-Wav. (if there is an OS X alternative, please let me know.
3) Copy DD-Wav back onto Mac.
4) Open m2v in Quicktime Pro.
5) Open dd-wav in quicktime pro, then add to the m2v movie.
6) Export to Quicktime. h.264 (i used one pass to save time @2400kbps) w/ Apple Lossless 44.1 stereo w/o streaming box clicked.
7) Add to iTunes Library
8) Play on AppleTV with glorious 5.1 DD!
I tried to folloow these steps but the problem that I am having is on step 6 when quicktime pro only let me choose either mono channels or streao (L R) in the audio channels settings when I try to export an audio file or a movie with a soundtrack. All the other options such as 5.1, 6.1 and 7.1 are grayed out. I tried every single combination of export format, but I always end-up with the same problem. I also tried to importing dd-Wav file directly to itunes (no export via quicktime). In this case my reciver was able to decode the 5.1 channles but I couldn't get any sound.

Anyone else is having the same problem with quicktime pro. I tried to call apple support but they told me that they only support installations issues (;
jbrjake
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Re: Apple TV and 5.1 support - some definitive answers

Post by jbrjake »

agata wrote:
6) Export to Quicktime. h.264 (i used one pass to save time @2400kbps) w/ Apple Lossless 44.1 stereo w/o streaming box clicked.
I tried to folloow these steps but the problem that I am having is on step 6 when quicktime pro only let me choose either mono channels or streao
Um how about you try actually following the steps, then? Your only problem is your refusal to follow the directions.
MichaelLAX

Re: Apple TV and 5.1 support - some definitive answers

Post by MichaelLAX »

I thought that using QT Pro to Save As MOV with AC3 passthrough works for 5.1 without all of the WIndows conversion (once the ATV has been hacked with Perian, of course)? Not having a digital input on my Panasonic Home Theater, I can't test it (I just use Dolby Pro Logic II in the meantime).
flybynight
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Re: Apple TV and 5.1 support - some definitive answers

Post by flybynight »

rhester wrote:Of course - but then you run the risk that the LFE data is duplicated in the mains (and it nearly always is) and you will thus end up playing both in-phase and out-of-phase at the same time (and this is Not Good(TM)).
And that's precisely why we don't encode LFE, at Dolby's recommendation.
Rodney
OK, that clears ups the confusion. The other posts made it sound like LFE was the only place it existed, causing a noticeable loss in bass. Is this just a limitation of their receiver then? Thanks!
flybynight
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Joined: Mon Feb 04, 2008 9:49 pm

Re: Apple TV and 5.1 support - some definitive answers

Post by flybynight »

Ok- I know this is a handbrake forum, but maybe this will help with the overall efforts.

First off, this will allow you to play on a DD receiver ONLY. If you try to play on your laptop, you get static... so that said.

1) Demux with MPEG Streamclip to M2V and AC3.
2) Copy AC3 to windows machine to use BeSweet to convert to DD-Wav. (if there is an OS X alternative, please let me know.
3) Copy DD-Wav back onto Mac.
4) Open m2v in Quicktime Pro.
5) Open dd-wav in quicktime pro, then add to the m2v movie.
6) Export to Quicktime. h.264 (i used one pass to save time @2400kbps) w/ Apple Lossless 44.1 stereo w/o streaming box clicked.
7) Add to iTunes Library
8) Play on AppleTV with glorious 5.1 DD!
Just to clarify, is step 8 an out-of-the-box ATV? No hacks or Perian? If so, that's exactly what I'm looking for. I don't need/want to play the file on my computer, just on my home theater w/ ATV and Onkyo 705 receiver.
Too bad there isn't a way to just have HB make that file in one step. I don't have a Windows machine to do step 2. If there were all-Mac tools available, I'm sure an Automator script could be set up.

But, perhaps it will all change when the "Take 2" ships... eagerly waiting!
sfatula
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Re: Apple TV and 5.1 support - some definitive answers

Post by sfatula »

SPDIFER and the other tools converted to Mac OSX, the links are no longer valid.

For those who developed it, any chance that it also converts the other direction? i.e., a DDWAV to AC3? The AC3 to DDWAV is great for the purposes outlined here, but, there are uses for DDWAV to AC3 as well. Yes, besplit works but I'd like a Mac only solution.

Please advise.

Steve
Cavalicious
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Re: Apple TV and 5.1 support - some definitive answers

Post by Cavalicious »

Who the hell resurrected this thread? ...and why? all information in this thread is outdate and/or unnecessary.

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