[9fans] USB headphones

[9fans] USB headphones

[Joel Salomon]

I just purchased a set of USB headphones (Gigaware 43-122) to try on
my laptop.  When I run usb/usbaudio, I get the message:
	usb/usbaudio: Can't configure record for 44100 or 48000 Hz
Does this mean the device isn’t supported?  The list of supported
devices in usb(4) doesn’t seem to include any headphones; has anyone
had any luck with a (hopefully not too expensive) set?  How much
hackery is required to get an arbitrary (supposedly “USB Certified”)
headset to work with Plan 9?

--Joel

Re: [9fans] USB headphones

[Richard Miller]

Can you try the version of usbaudio in /n/sources/contrib/miller
and see if that helps?

Re: [9fans] USB headphones

[Joel Salomon]

> Can you try the version of usbaudio in /n/sources/contrib/miller and
> see if that helps?

term% usb/usbaudio -V
Audio output unit 1
Device can record from <unnamed>
Audio input unit 7
Device can play to USB Streaming
Audio Selector Unit 8
Audio Feature Unit 9, not known what for
	mute control on master channel
	volume control on channel 1
	volume control on channel 2
Audio Feature Unit 10 for Record
	mute control on master channel
	volume control on master channel
	agc control on master channel
Audio Feature Unit 13 for Record
Second feature unit (10, 13) on record
	mute control on master channel
	volume control on master channel
Audio Mixer Unit 15
Interface 1, alt 1: stereo, 16 bits, discrete frequencies are: 48000 44100
Interface 2, alt 1: mono, 16 bits, discrete frequencies are: 48000 44100
Playback on endpoint 1
Record on endpoint 2
Buttons on endpoint 3
usb/usbaudio: Can't configure record for 44100 or 48000 Hz

On the other hand...

term% /n/sources/contrib/miller/usb/audio/usbaudio -V
Audio output unit 1
Device can record from Microphone
Audio input unit 7
Device can play to USB Streaming
Audio Selector Unit 8
Audio Feature Unit 9, not known what for
	mute control on master channel
	volume control on channel 1
	volume control on channel 2
Audio Feature Unit 10 for Record
	mute control on master channel
	volume control on master channel
	agc control on master channel
Audio Feature Unit 13 for Record
Second feature unit (10, 13) on record
	mute control on master channel
	volume control on master channel
Audio Mixer Unit 15
	Mixer 15 for output AND input
Interface 1, alt 1: stereo, 16 bits, discrete frequencies are: 48000 44100
Interface 2, alt 1: mono, 16 bits, discrete frequencies are: 48000 44100
Playback on endpoint 1
Record on endpoint 2
Buttons on endpoint 3
Setting default play parameters: 44100 Hz, 2 channels at 16 bits
Setting default record parameters: 44100 Hz, 2 channels at 16 bits
/n/sources/contrib/miller/usb/audio/usbaudio: Can't configure record for 44100 or 48000 Hz

Slightly different debugging info—the version on sources recognizes a
bit more about the headphones—but neither works.

Any clues or tips?

--Joel

Re: [9fans] USB headphones

[Richard Miller]

> Any clues or tips?

My theory is that your headpones have a mono-only microphone, and
usbaudio insists on configuring stereo input.  I've made another
change to /n/sources/contrib/miller/usb/audio/usbaudio which
might help.

Re: [9fans] USB headphones

[Joel Salomon]

> > Any clues or tips?
>
> My theory is that your headpones have a mono-only microphone,

Sounds right.

> and usbaudio insists on configuring stereo input.  I've made another
> change to /n/sources/contrib/miller/usb/audio/usbaudio which
> might help.

I'll try that one next chance I get; thanks.

--Joel

Re: [9fans] USB headphones

[Joel Salomon]

> My theory is that your headpones have a mono-only microphone,

That turned out to be exactly right.

> and usbaudio insists on configuring stereo input.  I've made another
> change to /n/sources/contrib/miller/usb/audio/usbaudio which
> might help.

	term% /n/sources/contrib/miller/usb/audio/usbaudio
	Warning, can't configure stereo recording, configuring mono instead
...but now I have audio!
	term% cdfs
	term% cat /mnt/cd/a000 > /dev/audio
and I’m listening to Sibelius.  Thanks, Richard.

Any reason this version of usbaudio isn’t the official one?

Now to get juke(7)—or something reasonable—working nicely⋯

--Joel

Re: [9fans] USB headphones

[Richard Miller]

> and I’m listening to Sibelius.  Thanks, Richard.

Great.  Have you checked whether input works too?

> Any reason this version of usbaudio isn’t the official one?

I was just waiting for feedback in case my changes had broken
any devices which worked before.  I'll submit it as a patch now.

-- Richard