[-Matt-]

I'm just wondering if I can use xbmc (running on an apple tv) to send HD audio to my av amp over HDMI.

Specifically I would like to play 192kHz 24bit stereo flacs and 96kHz 24bit multichannel flacs.

Does anyone know if this is possible?

[interceptor121]

Definitely two channels I have not heard about multichannel but you can pass discrete multichannel through HDMI for sure once decoded

[-Matt-]

Thanks for the reply...

I gave it a try and I have run into some problems.

Here is a source of some test files: http://www.2l.no/hires/index.html


The first file I click on will play (I get sound) but my reciever says that I am only getting stereo at 44.1 kHz. It seems like the apple tv is downsampling.

...Then if I try to click on any other file I completely lose all system sound and have to restart apple tv to get it back.


Note I have selected the following options:

Audio output: Digital
Dolby Digital (AC3) capable receiver: Yes
DTS capable receiver: Yes
Audio output device: Default Output Device
Downmix multichannel audio to stereo: No


The receiver is a Denon AVR4306.

I'm just in the process of reading up on how to get a proper error log, once I figure it out I will post one here.

[interceptor121]

As I said it could be problematic on multi channel have you tried the stereo recordings first?
Logs are in frontrow/library/logs

[-Matt-]

Here you go...

http://pastebin.com/0a5A7iuY

[-Matt-]

I need to test more carefully but I think that it is the multichannel ones that cause all sound to stop. I think the stereo ones play but are downsampled to 44.1kHz which kind of defeats the object!

[garyi]

I think you are running into the 'main' issue. XBMC does not change the audio output on the mac OS on the fly, like say Amarra does (not the same price either haha)

I have requested this but sadly the music section of XBMC is more the runt of the litter.

I am not complaining, XBMC is free and super. Options that change OSXes audio on the fly all cost money.

[-Matt-]

I'm not sure exactly what all of this means but in my error log it says:

Code:

763.16:43:57 T:2684407808 M: 13201408    INFO: PAPlayer: Playing smb://????:[email protected]/EXTERNAL_HD/Music/HD_Music/Beethoven_Adagio_192kHz.flac
764.16:43:57 T:2684407808 M: 13217792   DEBUG: PAPlayer: Creating new audio renderer
765.16:43:57 T:2684407808 M: 13217792    INFO: AudioRendererFactory:  not a explicit device, trying to autodetect.
766.16:43:57 T:2684407808 M: 13217792   DEBUG: SetActiveDevice - SetActiveDevice from 1 to 2
767.16:43:57 T:2684407808 M: 13217792   DEBUG: RemoveActiveDevice - Removing device 1
768.16:43:57 T:2684407808 M: 13217792   DEBUG: CCoreAudioHardware::FindAudioDevice: Returning default device [0x0102].
769.16:43:58 T:2684407808 M: 12742656   DEBUG: CoreAudioRenderer::Initialize: Input Stream Format [lpcm] Mixable 2 Channel 16-bit Signed Integer (192000Hz)
770.16:43:58 T:2684407808 M: 12759040   DEBUG: CoreAudioRenderer::Initialize: Output Stream Format [lpcm] Mixable 4 Channel 32-bit Floating Point (44100Hz)
771.16:43:58 T:2684407808 M: 12734464   DEBUG: CoreAudioRenderer::Initialize: Renderer Configuration - Chunk Len: 2048, Max Cache: 768000 (1000ms).
772.16:43:58 T:2684407808 M: 12734464    INFO: CoreAudioRenderer::Initialize: Successfully configured audio output.
773.16:43:58 T:52358656 M: 12730368   DEBUG: thread start, auto delete: 0
774.16:43:58 T:52358656 M: 12730368   DEBUG: PAPlayer: Thread started
775.16:43:58 T:52358656 M: 11558912    INFO: AudioDecoder: File is queued
776.16:43:58 T:52358656 M: 11550720   DEBUG: CoreAudioRenderer::Resume: Resuming Playback.
777.16:43:58 T:2684407808 M: 11096064   DEBUG: CAnnouncementManager - Announcement: PlaybackStarted from xbmc
778.16:43:58 T:2684407808 M: 11096064   DEBUG: OnPlayBackStarted - Playback has started

It looks to me like xbmc can't find a suitable output device then tries to create one.

Is it possible to edit a configuration file somewhere and add some more preset output devices. This might allow xbmc to switch output frequencies correctly.

I'm thinking there must be something analagous to Xorg.conf (but for the core audio device) which has 44.1kHz hard coded into it.


This is all new to me so sorry if my guess is way off the mark.

[-Matt-]

Just to make sure I'm not barking up the wrong tree...

Is it even possible for the apple tv hardware to output at 192kHz 24bit over HDMI?

How about 96kHz 24bit multichannel?

Am I up against a hardware limitation or is it just a software problem?

[garyi]

Ah and there is your second problem I never read your ATV ownerage point. I think the hardware supports it but I have never got it too work in the main ATV software just came out silent.

[davilla]

You might have better luck running an atv(linux) variant.

[-Matt-]

Thanks for the suggestion.

I already found this thread:

http://forum.xbmc.org/showthread.php?tid=59877

...as you say, it looks like it is possible under linux. I guess that confirms that the hardware is capable and it is just a software problem.

Is there any chance that the osx audio driver will be upgraded anytime soon?


I'm just a bit hesitant about starting again with linux just to get 192/24 working. At the moment, everything else that I want to use on the AppleTV is working nicely! Also, I guess it would mean loosing itunes movie downloads etc.

[davilla]

Is there any chance that the osx audio driver will be upgraded anytime soon?

Magic 8-Ball says No.