[neil.j1983]

Hi,

I know I don't have any logs, so my post isn't much use. But I convert all my blurays audio into either AAC or FLAC. For the ones with 5.1 audio this works brilliantly. However, for the 7.1channel movies (mainly the marvel movies, avengers, cap, etc) the channels are all messed up.

From memory I'm currently running the beta build, with an nvidia gt240 connected via hdmi to an onkyo 606 with the latest nvidia drivers.

I have my audio configuration set to 7.1 so I'm not sure why these are all going to the wrong channels.

At the weekend I can post logs/samples I just wanted to throw this out as all the posts about this are quite old and I wondered if anyone else notices this?

[neil.j1983]

here is a sample with different audio formats: https://www.dropbox.com/s/csnm34xap2176s...ormats.mkv

it has 5.1 flac, 7.1 flac, 5.1 aac, 7.1 aac, normal 5.1 ac3 and 7.1 TrueHD

If someone else could test this, with their speaker setup on 5.1 and then again on 7.1 to see if the channels come out in the the right place that would be great!

[waituna]

I only have a 5.1 speaker setup. When I play your sample the only audio track that plays the rear surround channels correctly is Dolby Digital 5.1 - all the other audio tracks play thru the front speakers.

See my post about this same issue: http://forum.xbmc.org/showthread.php?tid=147544

[neil.j1983]

i will try this in windows too, to see if it is platform specific.

through MPCHC using LAV Filters all files play correctly with perfect channel mapping.

[neil.j1983]

sorry for the double post, but I've just realised waituna and I are talking about seperate issues!

Waituna is experiencing channel mapping which is wrong on the ION chipset, this used to be fixable with an asound.conf but because AE does not allow a custom output for sound there is noway to choose the custom output described in asound.conf as your sound output. I realise this is an nvidia oversight, but there is no workaround currently (that i know of), this happens with anything above 2.0. Bitstreaming solves this issue, but it means decoding of anything above 2.0 is useless, and this means TrueHD and FLAC decoding.

I am experiencing mismapped channels ONLY on >5.1 content. All 5.1 files decode with correct channel mapping. If I decode 7.1 (I have no 6.1 to try) then the channels are all-over the place. EVERYTHING 5.1 works fine. This is on a GT240.

[un1versal]

There are PRs to attempt to fix this but nothing is going to happen any-time soon.

https://github.com/xbmc/xbmc/pull/1490

Try that or wait?

uNi

[neil.j1983]

Oh, I'll definitely wait. I'm just glad someone is working on it.

[un1versal]

From the discussion on PR they cant agree on what should be best, I doubt this will be done anytime soon (if ever)

+ Flacs dont have channel layout (as per PR information from DDDamian) its guessed at best.

uNi

[PatrickVogeli]

I have a similar problem, the one with the ION 1, but it is a hardware problem. If I use speaker-test, the output is wrong. Until frodo, I could specify a custom output device to fix this, now that I can't, the channel output is wrong again.

What does this mean for me? Well, if I cannot fix it, Frodo is just of no use to me and I'll have to go back to Eden, where this could be fixed.

I realize it's a HW bug, but still, it was fixable and now it isn't, too bad.

[DDDamian]

That PR addresses only downmixing channels. I assumed from the above that this is an issue on a true 7.1 setup? I have true 7.1 here running Win 7 x64 and they map correctly, but will follow this thread.

[neil.j1983]

i think that although FLAC has no established standard that XBMC should follow the eac3to output method.

I can't think of a 7.1 source that isn't bluray or hddvd. If they have been processed by eac3to then they will have been output in the same way(or am i wrong?).

I'll just have to move to windows if this isn't sorted in frodo.

and yes, this is outputting 7.1 straight from xbmc to a reciever.

[PatrickVogeli]

I don't know if it may help somebody, but I have fixed my issue. It was a bit harder than it Eden, but it seems to work great. Also, thanks for posting that test mkv file, it's really handy!

http://forum.xbmc.org/showthread.php?tid=147733

[neil.j1983]

just tried on RC1. Flac 7.1 seems to be fine. Either straight to 7.1 or downmixing to 5.1.

AAC 7.1 is all over the place. either when outputting 7.1LPCM or downmixing to 5.1

Also tried windows, and same channels go to the same places.

[Crayden]

from my experience and testing:

7.1 flac:
works fine with xbmc, vlc and windows direct show (ffdshow, lav)

xbmc 7.1 aac (hdmi 7.1 channel using direct sound):
left -> left
center -> center
right -> right
right surround -> right surround
left surround -> left surround
right rear surround -> mixed to center and front right
left rear surround -> mixed to center and front left

ffdshow 7.1 aac mixer enabled using an identity matrix:
left -> missing
center -> center
right -> missing
right surround -> right
left surround -> left
right rear surround -> right rear surround
left rear surround -> left rear surround
lfe -> lfe

ffdshow 7.1 aac mixer disabled:
left -> left + center
center -> center
right -> right + center
right surround -> right
left surround -> left
right rear surround -> right rear surround
left rear surround -> left rear surround
lfe -> lfe

Before testing I thought that it might be decoder related as LAV and FFDSHOW are unable to play 7.1 aac correctly but VLC is.
Hopefully someone will look into it a bit further. I'd be willing to look into that issue myself but I don't have enough time till february

edit:
Of course the issue is the same on linux. That's why I think it's related to the decoder.

[neil.j1983]

wow, nice post. That is what it sounds like to me too. I haven't had the time to do anything constructive towards this, so thanks for confirming/delving deeper into this.