AppleTV to support Dolby5.1 Natively

[Daelemans]

...I know a secret...

Cool Beans!

[le pendu]

...I know a secret...

YAY!

[flybynight]

DTS is actually better than Dolby Digital and its sad that Apple TV doesn't support it...

"Better" is debatable. "Louder" is true for sure. But, yes, support for more variants would be better. Choice is good and many do consider DTS to be better.

[flybynight]

...I know a secret...

Great! ...um, now, how do we use it? Sorry, I'm not a "source code" kinda person. Is there an easy way to get this into the existing HB app, or will us who are only semi-geeks have to wait for 0.9.2?

[BobVB@mac.com]

I can confirm the patch does allow AC3 - I am watching Batman Begins with DD5.1 sound as I type.

THANK YOU!!!

(lets see at 4 or 5 qued a night I can do one of my jukeboxes in 3 months

[nightstrm]

...I know a secret...

Great! ...um, now, how do we use it? Sorry, I'm not a "source code" kinda person. Is there an easy way to get this into the existing HB app, or will us who are only semi-geeks have to wait for 0.9.2?

I'd wait, because even if you figure out the simple commands to compile the code (and publicly available in the wiki), something will likely not be right and you'll be back here wondering why in the world code that is meant for developers to work on isn't producing the result you are expecting. The current code is far from being a complete solution and is more a proof-of-concept at this point IMO.

Sometimes it is alright to live on the bleeding edge with HB, other times it just leads to you re-encoding the same video 10 times in a row (not that I'm talking from personal experience or anything ).

[flybynight]

I'd wait, because even if you figure out the simple commands to compile the code (and publicly available in the wiki), something will likely not be right and you'll be back here wondering why in the world code that is meant for developers to work on isn't producing the result you are expecting. The current code is far from being a complete solution and is more a proof-of-concept at this point IMO.

Sometimes it is alright to live on the bleeding edge with HB, other times it just leads to you re-encoding the same video 10 times in a row (not that I'm talking from personal experience or anything ).

'Nuff said! I know when I'm in over my head. For now, I can do the mkv work-around. Any idea on a timeline for the next compiled version/update? Keep up the good work!

[dbendixen]

Someone's been hard at work I see. Is this implemented into the GUI as another option or just in the 6-channel passthrough option?

[BobVB@mac.com]

Someone's been hard at work I see. Is this implemented into the GUI as another option or just in the 6-channel passthrough option?

Its a 3rd mp4 option ATC/H.264 / AC-3

[dbendixen]

I'll have to try it tomorrow.. After I updated the SVN to 1262 and typed "make" in the term, it resulted in "Build Failed." That's the first time I've had a failed build.

[BobVB@mac.com]

I'll have to try it tomorrow.. After I updated the SVN to 1262 and typed "make" in the term, it resulted in "Build Failed." That's the first time I've had a failed build.

I used 'jam' and got a failed build too... a friend told me to run 'make clean' and './jam clean' and try again and then it compiled in moments.

[petvas]

I tried make clean and ./jam clean but it doesn't work
I get Build failed all the time

[Deleted User 5579]

I tried make clean and ./jam clean but it doesn't work
I get Build failed all the time

Tried the suggestions above. Got the same results as you with the Build failed....

[dynaflash]

this is why we do not support development code from the svn. Unless you are up to speed with where we are at in the svn, ymmv.

make hasnt worked properly in the svn for some time. right now its jam only. make never works until we update the ub contrib packs.

[petvas]

Thanks, ./jam worked fine

[dynaflash]

Second reason svn builds are tough to keep up with. There is a sync issue in latest svn.
We won't be posting svn bugs, so as always ymmv.
When we have something stable you will know.

[rils]

Greetings! A few points that may be of interest:

+ Dolby Digital and AC3
Dolby Digital was developed by Dolby to bring multichannel sound to the home, and to be using existing hardware for digital audio communication between devices, i.e. optical and coaxial SPDif. To that effect, the AC3 stream "fits" into the footprint of a Stereo PCM 48KHz/24 bits signal. When it comes to the MP4 container, the AC3 stream is packed like a PCM 48KHz/24bits/stereo signal. Because the Codec is CBR, sync operates just the same way as a wave.

+ Dolby: fees, and more fees...
Dolby charges equipment manufacturers a "per channel" fee; when a DVD player only sports stereo outputs, the dolby digital stream is decoded into 5 discrete channels, then downmixed into 2 channels, and the DVD manufacturer pays the 2 channels fee to Dolby for each device sold. If the DVD player supports 5.1 outputs, the DVD manufacturer pays for 6 channels for each device sold, etc...

+ Apple TV 2.0.
In fact, the hardware seldom changed between 1.0 and 2.0, and there was no reason to as the device was quite over-engineered from the jo. However, Apple wanted to propose Dolby Digital to boost its movie rental gig, and be on an even foot with Cable and Direct TV...
If ATV decoded the AC3 stream then downmixed it to 2.0 (like a DVD player), Apple would have to pay Dolby for each device sold. It would also be very difficult to provide current users with this functionality as a "free update", as the license would also have to be paid for each device updated- a deployment nightmare! But if ATV doesn't decode Dolby Digital, then movies provided with DD soundtrack would be mute on the analog stereo out... Not an acceptable solution either!

Here is the solution:
Apple MP4 movies sport a stereo downmix channel in the audio track 1, encoded in AAC, up to 160KBPS. They also pack the DD stream in Audio Track 2. Et Voila! ATV provides the user with the stereo channel AND DD, without ever decoding it, thus bypassing the various Dolby fees. I do not know at this time is the Audio track 1 can still support 6x discrete AAC channels, but it is likely as some of the material distributed by Apple was presented this way, and Apple probably wants to keep compatibility. More on this later!

+ Now DTS?
There is absolutely no technical reason for ATV not to support DTS passthrough... Besides licensing! Alike DD, the home version of DTS was engineered to fit in the SPDif channel, so DTS passthrough should be just the same as DD. For those who are still wondering, yes, DTS sounds a tad better, mostly due to a better, more recent Codec used at a higher bitrate. The MP2 Codec used for Dolby digital is very obsolete, and doesn't reach "CD quality" at the used bitrate.


+Multichannel AAC, implemented first by Apple, was designed to be stored in a file, but not carried over a digital link, so there isn't any "packing" rules yet to send it to the receiver... Furthermore, AAC is a tad more complicated to decode than MP2, so it is likely that a lot of receivers out there would need to be... replaced! Given that the new multichannel audio formats from DTS and Dolby use a lossless audio Codec, I do not see a lot of future for multichannel AAC, and certainly no near term support from receiver manufacturers...

Cheers!

[petvas]

I tried make clean and ./jam clean but it doesn't work
I get Build failed all the time

Tried the suggestions above. Got the same results as you with the Build failed....

Hi,

Try the following

Redownload the svn sources with Rapid SVN
Do a ./jam clean
then do ./jam

Hopefully that will work

If not, then instead of doing ./jam clean, do a "make clean" but download the SVN and start again please

[dbendixen]

Greetings! A few points that may be of interest:

What does this mean to us?
It's not Apple's responsibility to keep track of users who create their own movies, right? So they wouldn't care about HB Devs making an AC-3 audio option for MP4 files. Am I totally off track on this?

[BobVB@mac.com]

Oh and just an FYI as this obviously isn't Handbrake's problem: You can't add artwork to these new files via iTunes - all the other tag fields 'stick' but trying to paste in artwork doesn't work.

[Deleted User 5579]

I tried make clean and ./jam clean but it doesn't work
I get Build failed all the time

Tried the suggestions above. Got the same results as you with the Build failed....

Hi,

Try the following

Redownload the svn sources with Rapid SVN
Do a ./jam clean
then do ./jam

Hopefully that will work

If not, then instead of doing ./jam clean, do a "make clean" but download the SVN and start again please

Got it, will give it a shot in a bit. Thanks for the tips petvas - dynaflash.

[dynaflash]

Oh and just an FYI as this obviously isn't Handbrake's problem: You can't add artwork to these new files via iTunes - all the other tag fields 'stick' but trying to paste in artwork doesn't work.

With metaX the artwork and everything else sticks when used in iTunes. havent tested it with the atv yet for artwork but I imagine it should work fine.

[dbendixen]

Oh and just an FYI as this obviously isn't Handbrake's problem: You can't add artwork to these new files via iTunes - all the other tag fields 'stick' but trying to paste in artwork doesn't work.

"new files" being the AC-3 passthrough files? I wonder what's different about the files that doesn't let the artwork stick?

Sorry for the stupid question, but where can I get metaX?

[dynaflash]

Sorry for the stupid question, but where can I get metaX?

er, googling "metax" tells me http://www.kerstetter.net/page53/page54/page54.html

[dbendixen]

I'm sorry, that was a lazy moment. I've had too much going on with work and my managerial accounting class. My brain is full... can I be excused please?