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4.0 (Quad) FLAC downmixed to Stereo over HDMI - Printable Version

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+--- Thread: 4.0 (Quad) FLAC downmixed to Stereo over HDMI (/showthread.php?tid=68982)



4.0 (Quad) FLAC downmixed to Stereo over HDMI - gjwAudio - 01-17-2014

Hi All

Is there a fix for playing 4.0 multi-channel FLAC files over HDMI, in OE v3.2.3/Frodo 12.2 ? I have a large number of quadraphonic discs I wish to transcode to MCH-FLAC, and initial tests are disappointing.

I have searched for similar reports (ie: 4.0 FLAC downmixed to 2.0), but find nobody raising this issue. xbmc is recognizing the number of input channels as 4 (indicated by hitting "O" key during playback), but refuses to send anything but Stereo PCM over HDMI.

Curiously. odd-numbered MCH-FLACs play "correctly"... both 3.0 and 5.0 files are formatted as 5.1 PCM > HDMI, and map to the correct locations. My processor identifies the input stream as 5.1 PCM (L/ C/ R/ LFE/ LS/ RS). Six channel files behave as expected.

Audio output in xbmc is configured for HDMI/ 5.1 channels/ AC3/ dts/ AAC/ Multichannel LPCM calable. While the processor is only HDMI v1.1 compliant (a 2005-vintage Anthem D2), it accepts up to six channels of 24bit/96KHz PCM - sufficient to the task, if only xbmc would format the appropriate number of PCM channels.

Can anyone say how to pass 4 LPCM channels over HDMI - unmolested by downmixing to stereo ?

Thanks in advance for advice and pointers.


4.0 (Quad) FLAC downmixed to Stereo over HDMI - chewitt - 01-17-2014

I'd start by updating to a current dev build because the 3.x and Frodo codebases are not going to be developed any further. If you still have the issues under Gotham I'd recommend you drop into the #openelec IRC support channel and discuss this with 'fritsch' as he's the public half of the duo that created ActiveAE.


4.0 (Quad) FLAC downmixed to Stereo over HDMI - gjwAudio - 01-23-2014

Thanks chewitt for offering the Gotham suggestion.

Haw-haw... I can't get the system to even start:
Code:
Error in prepare_sysroot: final_check: could not find system
Starting debugging shell.... type exit to quit
sh: can't access tty: job control turned off
Being a linux-NooB, I'm completely at a loss for troubleshooting something so fundamental.

I tried two nightly builds - installed to two different USB sticks:
1) OpenELEC-Generic.x86_64-devel-20140116194710-r17010-g4dd0018.tar
2) OpenELEC-Generic.x86_64-devel-20140121154944-r17084-gdd3aff8.tar
with identical results.

Why am I so "lucky" ?

::UPDATE::
2014-01-24: issue taken over to Gotham Generic "nightly" builds thread.


4.0 (Quad) FLAC downmixed to Stereo over HDMI - gjwAudio - 02-26-2014

2014-02-26: Back In Action (runnung OpenELEC Gotham Nightlies) - Same Funky Behaviour Persists... BUT

OK, so just to follow through with an update... I got my NUC upgraded to running latest Gotham nightlies from "snapshots.openelec.tv"... and presumably the ActiveAE audio engine is in force.

Tested again with these files:
[3.0] L-C-R (24b-96K).flac
[4.0] Lf-Rf+Ls-Rs (24b-48K).flac

...and got the same disappointing result on Gotham playing the Quad file. Just before posting a debug log, I checked for anything obviously out of place. Nope, seems xbmc is OK with the 4.0 channels:
Code:
DEBUG: CAESinkALSA::GetChannelLayout - Input Channel Count: 4 Output Channel Count: 4
DEBUG: CAESinkALSA::GetChannelLayout - Requested Layout: FL,FR,BL,BR
DEBUG: CAESinkALSA::GetChannelLayout - Got Layout: FL,FR,BL,BR
DEBUG: CActiveAESink::OpenSink - ALSA Initialized:
DEBUG: Output Device : HDA Intel PCH
DEBUG: Sample Rate : 48000
DEBUG: Sample Format : AE_FMT_S32NE
DEBUG: Channel Count : 4
DEBUG: Channel Layout: FL,FR,BL,BR

...soooo... the finger points squarely at the AVR (Anthem D2) - and boy-OH-boy are they going to have some explaining to do !

All Hail xbmc Development Team !!

Thanks for playing.