myrison Wrote:Thanks for posting. What is your setup on which you found this change necessary? (i.e. Linux version, hardware, Nvidia driver, etc.)

Thanks.

Den4t Wrote:Hi !

As many users i have problems with channel mappings, after some experiments i
found solution for me, bun not test it actively.
First, adding some code to ALSADirectSound.cpp, for right mapping 8 chan. flac & pcm:
else if (strstr(strAudioCodec, "DMO") || strstr(strAudioCodec, "FLAC") || strstr(strAudioCodec, "PCM"))
{
if(iChannels == 6)
deviceuse = "xbmc_win51:'" + EscapeDevice(deviceuse) + "'";
else if(iChannels == 5)
deviceuse = "xbmc_win50:'" + EscapeDevice(deviceuse) + "'";

>>this 2 lines added - new mapping in xbmc asound.conf
>> else if(iChannels == 8)
>> deviceuse = "xbmc_win71:'" + EscapeDevice(deviceuse) + "'";

}

this mapping in xbmc asound.conf file:
pcm.xbmc_win71 {
@args.0 SLAVE
@args.SLAVE {
type string
default "default"
}
type route
slave {
pcm $SLAVE
channels 8
}
ttable {
0.0= 1
1.1= 1
2.4= 1
3.5= 1
4.2= 1
5.3= 1
6.6= 1
7.7= 1
}
}

For right 5.1 AAC mapping i use this one, instead of original:
pcm.xbmc_aac51 {
@args.0 SLAVE
@args.SLAVE {
type string
default "default"
}
type route
slave {
pcm $SLAVE
channels 6
}
ttable {
0.0= 1
1.1= 1
2.4= 1
3.5= 1
4.2= 1
5.3= 1
}
}

and of course, i use alsa patch and system alsa mapping from this thread,
thanks Alan !

bitlisz Wrote:I have tried your solution, but not work fine.
Im pretty sure that not correct the channel mapping with truehd5.1 (maybe only with AAC, but i dont think so, maybe some channel still mixed)
Check this sample: DDTrueHD 5.1 (I will reupload if deleted)

Den4t Wrote:Hi !
Can't download the sample for now, rapidshare overloaded, will try tomorrow.
One question - is this audio only or have a video track ?
If this audio only, i think, xbmc use PAPlayer by default, can you play
the sample with DVDPlayer ? PAPlayer use another mapping scheme, i think.
With DVDPlayer you will see in xbmc.log:
DEBUG: Initialize - using alsa device xbmc_win71:'plug:hdmi'

alanwww1 Wrote:Thanks guys for the great feedback.

I was on Holiday, but now back. As soon as i get my work in shape i put together a new guide with updated new Ubuntu, Alsa, XBMC, Nvidia driver.

Also i am interested in checking out Intel's new platforms with Proper channel detection a and mapping with OPEN SOURCE drivers. These platforms with Broadcom's Crystal HD chip for video decode, could be a great alternative of Nvidia ION.

pbjr Wrote:While googling, I found this 7.1 test file if it can help.

www.megaupload.com/?d=E5X4E34S

It came from this post here discussing 8 channel flac support.
http://www.hydrogenaudio.org/forums/lofiversion/index.php/t77207.html

bitlisz Wrote:But as I said no problem with any 7.1...
The problem only with:
Dolby Digital TrueHD 5.1 and AAC5.1 (swaping channels)
DTS from wav
Dolby Digital Plus (audio dropouts/lots of hdmi reconnects)
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