On Wed, 8 Nov 2017 19:15:05 +1100
Stephen Morris <samorris(a)netspace.net.au> wrote:
Hi stan, Ed replied in another thread that he found some info that
says that Logitech software is required to get the functionality
which is not available for Linux, so it looks like surround won't
work.
I issued the command aplay -Lv and I've put the output below. The
output snippet I've supplied seems to be indicating that it thinks
the headset is capable of surround sound, but I'm not sure if I'm
interpreting the information correctly.
sysdefault:CARD=Headset
G533 Gaming Headset, USB Audio
Default Audio Device
front:CARD=Headset,DEV=0
G533 Gaming Headset, USB Audio
Front speakers
surround21:CARD=Headset,DEV=0
G533 Gaming Headset, USB Audio
2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=Headset,DEV=0
G533 Gaming Headset, USB Audio
4.0 Surround output to Front and Rear speakers
surround41:CARD=Headset,DEV=0
G533 Gaming Headset, USB Audio
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Headset,DEV=0
G533 Gaming Headset, USB Audio
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Headset,DEV=0
G533 Gaming Headset, USB Audio
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Headset,DEV=0
G533 Gaming Headset, USB Audio
7.1 Surround output to Front, Center, Side, Rear and Woofer
speakers iec958:CARD=Headset,DEV=0
G533 Gaming Headset, USB Audio
IEC958 (S/PDIF) Digital Audio Output
That's how I would interpret it. I also have a usb sound device, and
I get that 7.1 entry, so it might just be generic to usb. It's easy to
check. Run the command
aplay -lv
and it should give you the subdevice to access the 7.1 on the headset,
as counter intuitively a device [digit] output.
e.g.card 2: Revolution51 [M Audio Revolution-5.1], device 1: ICE1724
IEC958 [ICE1724 IEC958]
If there isn't one for 7.1 for the headset, then it is just a generic
template for usb devices, and you are out of luck. That's what I get
for my usb device.
If there is one, then put on the headset, and play a wav file with the
following command. It has to be wav because aplay doesn't have any
decoding logic. You could probably use sox to convert something if you
don't have a wav file.
aplay -D plughw:0,[subdevice number goes here] [wav file name]
e.g. aplay -D plughw:0,6 pretty_song.wav
You could try different numbers from 0 through 7 as the second digit,
regardless of the aplay results, to see if there is any difference in
sound. One of them is likely to be IEC958 output, which is digital, so
will not be pleasant on your ears.
All that said, I think you are correct that surround won't work.
DTS:X will be a head related transfer function (HRTF). Those are
complex, so I doubt it is engineered into alsa, though an enterprising
coder might have taken it as a challenge.
https://en.wikipedia.org/wiki/Head-related_transfer_function