Hi to All and a Happy New Year to you,
I used some downtime over the holiday to look at the sound performance of my Mut@nt HD51 4k, because I couldn't get 5.1 surround sound coming out of it. I still can't.
This is my connection setup with my Mut@nt HD51 fitted with two Freeview receivers and currently running OpenVix-5.1.007.
Mut@ant ==> HDMI ==> Sony TV <==> HDMI ARC <==> Yamaha AVR ==> 5.1-Speakers
The Mut@ant is connected to Sony TV XE9005 using a HDMI cable and Sony in turn is connected over HDMI ARC to a Yamaha AVR. The Yamaha, which is capable of processing mpeg4-AAC, receives the PVR audio over HDMI ARC, while the TV displays the picture.
Without the Mut@ant running, when the Sony TV is receiving a Freeview HD channel itself which shows up as 'Audio AAC 3/2.1' on its info panel, the Yamaha is able to output 5.1 surround sound.
When the Mut@ant is switched on and is also receiving the same Freeview transmission, only a stereo sound comes out of the Yamaha.
I've also tried plugging in the HDMI from the Mut@ant directly into the Yamaha, but it made no difference. The sound transmitted from the Mut@ant over HDMI is always stereo.
Settings on Mut@ant:
I tried playing with the Audio settings available in Mut@ant's GUI. Under Automatic Language settings, I set it up to prefer AC3 and AC3+, but I expect these will only have an effect with satellite receivers. When I press the Audio button on the remote I see that the first of the two 'AAC-HE' English audio is selected - the second being the Audio Description [AD] for visually impaired. The 'Audio Channel' in the same menu is set to 'Stereo'. Switching the 'Audio Channel' between stereo/left/right makes no difference, nor does switching On the AC3 and DTS settings below.
AC3 Downmix Off
DTS Downmix Off
Audio Channel Stereo
I've also checked the streams captured in a Mut@ant .ts recording, which the TV was able to play with 5.1 surround sound. The recording contains two audio streams, the first of which is a 5.1 track surround sound stream and the second a stereo stream for [AD].
So the sound is captured with 5.1 audio tracks when available in the transmission, but will not be played out as such. Somehow it seems to be downmixed to stereo and I haven't found a way to disable this. I've looked at alsamixer, but I can't find a setting to enable 5.1 audio tracks there. This is alsa's stored settings:Code:Stream #0:1[0x66](eng): Audio: aac_latm (LC) ([17][0][0][0] / 0x0011), 48000 Hz, 5.1, fltp Stream #0:2[0x6a](eng): Audio: aac_latm (HE-AACv2) ([17][0][0][0] / 0x0011), 48000 Hz, stereo, fltp (visual impaired)
How can I enable live and recorded 5.1 surround sound to be played out of the Mut@ant?Code:state.bcm { control.1 { iface MIXER name 'Master Playback Volume' value.0 31 value.1 31 comment { access 'read write' type INTEGER count 2 range '0 - 63' } } control.2 { iface MIXER name 'PCM Playback Volume' value.0 8388608 value.1 8388608 comment { access 'read write' type INTEGER count 2 range '0 - 16777215' } } control.3 { iface MIXER name 'Decoder Audio' value true comment { access 'read write' type BOOLEAN count 1 } } }