[PROBLEM] Multichannel audio issue

[jcucurull]

Hello!

Thank you very much for the new release 9 of Moode. In this release multichannel audio is supported, however I am having an issue with it.

The issue is that when I select a multichannel FLAC, despite the signal sent to the AVR via HDMI has the 5.1 channels (they are shown in the AVR screen), the rear channels do not output any sound. I don't have any DSP enabled, just mentioning because I have read some issues in this forum about flipping channels with DSP enabled. Do you have any idea about which can be the issue?

Just clarify that my AVR is pretty old (it is a Marantz SR5001) and it does not like very much 7.1 signals, but with 5.1 signals (as it is the case) it should work fine. If I reproduce the same file with my bluray player I can hear the rear channels flawlessly.

Best,
Jordi.

[Tim Curtis]

Zip up the the file and PM me a download link. I'll try to repro the issue on my end.

[jcucurull]

Test audio file sent! Thank you!

[Tim Curtis]

When I play the Pink Floyd track on my Yamaha 5.1 AVR I don't hear anything from the rear surrounds. I have a couple of other multichannel flac files and all 6 channels produce sound.

I don't have any experience analyzing multichannel files to determine how they are encoded and why some channels don't play or are swapped or ??. Maybe someone with expertise in this area can help out.

[jcucurull]

When I play the Pink Floyd track on my Yamaha 5.1 AVR I don't hear anything from the rear surrounds. I have a couple of other multichannel flac files and all 6 channels produce sound.

I don't have any experience analyzing multichannel files to determine how they are encoded and why some channels don't play or are swapped or ??. Maybe someone with expertise in this area can help out.

I don't know what might be the difference with the test files you have. When I open it with Audacity it is clear that there sound in the rear channels.

I don't have more FLAC files to test it, the other are SACD and their corresponding rip files in DSF. But these ones I cannot reproduce them in Moode, because my AVR does not support DSS audio and it requires conversion to PCM (which I have via Bluray players).

[jcucurull]

Are there some logs that might give a hint of what is going on with the decoding of the file and mapping to the outputted channels?

[Tim Curtis]

Turn on MPD verbose logging to get codec details in /var/log/mpd/log

Channel mapping is I think handled by MPD + ALSA + Kernel HDMI and I don't know if there is a log or command that shows whats going on during that whole process.

Someone with a test file should post an issue to raspberrypi/linux
https://github.com/raspberrypi/linux/issues?q=

[jcucurull]

I have turned on the verbose logging of MPD and the information logged is more about the song played and the output format (S24LE). But there is nothing about the order of the channels.

On the other side, today I have tested another FLAC specifically for testing the channels and the order channels assignments were totally wrong when reproduced. Instead, if I reproduce it with my Bluray player the output was the expected one. I used the following FLAC file: https://github.com/sfiera/flac-test-file...und51.flac

[Nutul]

Hi,

did not read it all, as I am in a hurry ATM, but maybe there is something interesting:
https://hydrogenaud.io/index.php?topic=63269.0

[jcucurull]

I have checked it, but this post is more about a bug in "mplayer" and "gstreamer" that produced incorrect channel assignments, however it is from 2008, so I assume nowadays these kind of bugs should be fixed.