Re: [gentoo-user] USB Audio ?

2019-05-14 Thread Mick
On Tuesday, 14 May 2019 18:07:40 BST Jack wrote:
> On 5/14/19 12:26 PM, tu...@posteo.de wrote:

> > Question is:
> > How can I create such an "receiver" for USB Audio signals to play
> > them live with my PC?
> > 
> > Cheers!
> > Meino
> 
> That's very different from what I (and I suspect others) thought about
> your first posting.  You want to do USB audio input, not output.

May be worth searching the interwebs for 'USB streaming'.

> In
> this case, I don't think a usual USB audio device/dongle would even
> help.  My first suggestion is to just plug the USB from the Teensy into
> the PC, and see what dmesg shows, and what lsusb shows.  Searching on
> the manufacturer and device IDs shown by lsusb might lead to solutions,
> or at least to further lines of investigation.  Also, the Teeny docs
> might give more information about what kind of USB output their audio
> produces, and I wonder if you might find some good info on their forum?
> 
> Jack

Assuming dmesg shows the device is recognised and it offers something ALSA can 
work with, launch jackd/qjackctl and see what you can configure there.  I 
assume the synthesizer output is midi(?), in which case rosegarden will work 
with it.  If it is already processed into digital audio then you may be able 
to play the input with VLC, by either pointing to the USB device (file), or 
perhaps play with VLC's Capture Device options, if it is recognised as such.

-- 
Regards,
Mick

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Re: [gentoo-user] USB Audio ?

2019-05-14 Thread tuxic
On 05/14 01:07, Jack wrote:
> On 5/14/19 12:26 PM, tu...@posteo.de wrote:
> > On 05/13 11:24, Jack wrote:
> > > On 2019.05.13 23:10, tu...@posteo.de wrote:
> > > > Hi,
> > > > 
> > > > is it somehow possible to play USB-Audio on a PC without one of these
> > > > USB-dongle-"soundcards" (DACs)?
> > > > 
> > > > I searched the web and only got links to those dongles...
> > > > 
> > > > On the other hand: On the forum of the developers board one post
> > > > spokes of a "dummy" USB-Audio device...
> > > > 
> > > > How can I acchieve this?
> > > > 
> > > > Thanks for any help in advance!
> > > > Cheers!
> > > > Meino
> > > It's not clear what you really want.  Why would you want USB audio without
> > > an actual USB audio device?  Without a USB audio dongle/device/whatever,
> > > what would you have to actually produce sound?I can imagine a "dummy"
> > > USB audio device - but I can imagine it for testing the software, but not
> > > actually producing any sound, so why would you want it?
> > > 
> > > Jack
> > Hi Jack,
> > 
> > I don't wanted to pollute my posting with non-Linux details...but here
> > they are:
> > 
> > I habe a Teensy 3.6 by PJRC (=>https://www.pjrc.com/), which has an
> > USB-port. This port can be switched between a lot of USB-devices...
> > ...one of them is an USB-audio device (output).
> > The MK66FX1M0VMD18 uC has beside an FPU a DSP block.
> > With a certain (open source) firmware this chip can be used as an
> > synthesizer.
> > 
> > To cut costs I wanted no USB dongle to play the sound ... I wanted
> > to use my Linux PC as "Mega DAC"...so to say.
> > 
> > Question is:
> > How can I create such an "receiver" for USB Audio signals to play
> > them live with my PC?
> > 
> > Cheers!
> > Meino
> 
> That's very different from what I (and I suspect others) thought about your
> first posting.  You want to do USB audio input, not output.  In this case, I
> don't think a usual USB audio device/dongle would even help.  My first
> suggestion is to just plug the USB from the Teensy into the PC, and see what
> dmesg shows, and what lsusb shows.  Searching on the manufacturer and device
> IDs shown by lsusb might lead to solutions, or at least to further lines of
> investigation.  Also, the Teeny docs might give more information about what
> kind of USB output their audio produces, and I wonder if you might find some
> good info on their forum?
> 
> Jack
> 
> 

Hi Jack,

I already posted a question on the forum. The forum is about the
Teensy and not Linux.
Answer was:
"On a Win PC (I do not use Linux) you have to select the Teensy Audio
device (Open Sound Settings) to listen to teensy "

I attached a screenshot of the devices I could choose via bootloader
trickery.

lsusb (the relevant portion) reported this when switch to USB Audio:
[ 7722.526825] usb 6-2: new full-speed USB device number 18 using ohci-pci
[ 7722.691955] usb 6-2: New USB device found, idVendor=16c0, idProduct=04d2, 
bcdDevice= 2.77
[ 7722.691962] usb 6-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 7722.691966] usb 6-2: Product: Teensy Audio
[ 7722.691970] usb 6-2: Manufacturer: Teensyduino
[ 7722.691973] usb 6-2: SerialNumber: 4991790
[ 7722.700415] hid-generic 0003:16C0:04D2.0009: hidraw3: USB HID v1.11 Device 
[Teensyduino Teensy Audio] on usb-:00:12.0-2/input0
[ 7727.761957] usb 6-2: Warning! Unlikely big volume range (=4095), cval->res 
is probably wrong.
[ 7727.761965] usb 6-2: [49] FU [PCM Playback Volume] ch = 2, val = 0/4095/1


(hidraw is always present and is used to communicate with the
bootloader)

'udevadm monitor' shows this when plugging in the Teensy:
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[7867.891799] add  /devices/pci:00/:00:12.0/usb6/6-2 (usb)
KERNEL[7867.893472] add  /devices/pci:00/:00:12.0/usb6/6-2/6-2:1.0 
(usb)
KERNEL[7867.899759] add  
/devices/pci:00/:00:12.0/usb6/6-2/6-2:1.0/0003:16C0:04D2.000A (hid)
KERNEL[7867.900306] add  
/devices/pci:00/:00:12.0/usb6/6-2/6-2:1.0/0003:16C0:04D2.000A/hidraw/hidraw3
 (hidraw)
KERNEL[7867.900398] bind 
/devices/pci:00/:00:12.0/usb6/6-2/6-2:1.0/0003:16C0:04D2.000A (hid)
KERNEL[7867.900669] bind /devices/pci:00/:00:12.0/usb6/6-2/6-2:1.0 
(usb)
KERNEL[7867.900869] add  /devices/pci:00/:00:12.0/usb6/6-2/6-2:1.1 
(usb)
KERNEL[7873.197477] add  
/devices/pci:00/:00:12.0/usb6/6-2/6-2:1.1/sound/card3 (sound)
KERNEL[7873.197660] add  
/devices/pci:00/:00:12.0/usb6/6-2/6-2:1.1/sound/card3/pcmC3D0p (sound)
KERNEL[7873.197670] add  
/devices/pci:00/:00:12.0/usb6/6-2/6-2:1.1/sound/card3/pcmC3D0c (sound)
KERNEL[7873.197725] add  
/devices/pci:00/:00:12.0/usb6/6-2/6-2:1.1/sound/card3/controlC3 (sound)
KERNEL[7873.197793] bind /devices/pci:00/:00:12.0/usb6/6-2/6-2:1.1 
(usb)
KERNEL[7873.197862] add  /devices/pci:00/

Re: [gentoo-user] USB Audio ?

2019-05-14 Thread Jack

On 5/14/19 12:26 PM, tu...@posteo.de wrote:

On 05/13 11:24, Jack wrote:

On 2019.05.13 23:10, tu...@posteo.de wrote:

Hi,

is it somehow possible to play USB-Audio on a PC without one of these
USB-dongle-"soundcards" (DACs)?

I searched the web and only got links to those dongles...

On the other hand: On the forum of the developers board one post
spokes of a "dummy" USB-Audio device...

How can I acchieve this?

Thanks for any help in advance!
Cheers!
Meino

It's not clear what you really want.  Why would you want USB audio without
an actual USB audio device?  Without a USB audio dongle/device/whatever,
what would you have to actually produce sound?I can imagine a "dummy"
USB audio device - but I can imagine it for testing the software, but not
actually producing any sound, so why would you want it?

Jack

Hi Jack,

I don't wanted to pollute my posting with non-Linux details...but here
they are:

I habe a Teensy 3.6 by PJRC (=>https://www.pjrc.com/), which has an
USB-port. This port can be switched between a lot of USB-devices...
...one of them is an USB-audio device (output).
The MK66FX1M0VMD18 uC has beside an FPU a DSP block.
With a certain (open source) firmware this chip can be used as an
synthesizer.

To cut costs I wanted no USB dongle to play the sound ... I wanted
to use my Linux PC as "Mega DAC"...so to say.

Question is:
How can I create such an "receiver" for USB Audio signals to play
them live with my PC?

Cheers!
Meino


That's very different from what I (and I suspect others) thought about 
your first posting.  You want to do USB audio input, not output.  In 
this case, I don't think a usual USB audio device/dongle would even 
help.  My first suggestion is to just plug the USB from the Teensy into 
the PC, and see what dmesg shows, and what lsusb shows.  Searching on 
the manufacturer and device IDs shown by lsusb might lead to solutions, 
or at least to further lines of investigation.  Also, the Teeny docs 
might give more information about what kind of USB output their audio 
produces, and I wonder if you might find some good info on their forum?


Jack




Re: [gentoo-user] USB Audio ?

2019-05-14 Thread tuxic
On 05/13 11:24, Jack wrote:
> On 2019.05.13 23:10, tu...@posteo.de wrote:
> > Hi,
> > 
> > is it somehow possible to play USB-Audio on a PC without one of these
> > USB-dongle-"soundcards" (DACs)?
> > 
> > I searched the web and only got links to those dongles...
> > 
> > On the other hand: On the forum of the developers board one post
> > spokes of a "dummy" USB-Audio device...
> > 
> > How can I acchieve this?
> > 
> > Thanks for any help in advance!
> > Cheers!
> > Meino
> It's not clear what you really want.  Why would you want USB audio without
> an actual USB audio device?  Without a USB audio dongle/device/whatever,
> what would you have to actually produce sound?I can imagine a "dummy"
> USB audio device - but I can imagine it for testing the software, but not
> actually producing any sound, so why would you want it?
> 
> Jack

Hi Jack,

I don't wanted to pollute my posting with non-Linux details...but here
they are:

I habe a Teensy 3.6 by PJRC (=>https://www.pjrc.com/), which has an
USB-port. This port can be switched between a lot of USB-devices...
...one of them is an USB-audio device (output).
The MK66FX1M0VMD18 uC has beside an FPU a DSP block.
With a certain (open source) firmware this chip can be used as an
synthesizer.

To cut costs I wanted no USB dongle to play the sound ... I wanted 
to use my Linux PC as "Mega DAC"...so to say.

Question is:
How can I create such an "receiver" for USB Audio signals to play
them live with my PC?

Cheers!
Meino




Re: [gentoo-user] USB Audio ?

2019-05-14 Thread Mick
On Tuesday, 14 May 2019 04:24:46 BST Jack wrote:
> On 2019.05.13 23:10, tu...@posteo.de wrote:
> > Hi,
> > 
> > is it somehow possible to play USB-Audio on a PC without one of these
> > USB-dongle-"soundcards" (DACs)?
> > 
> > I searched the web and only got links to those dongles...
> > 
> > On the other hand: On the forum of the developers board one post
> > spokes of a "dummy" USB-Audio device...
> > 
> > How can I acchieve this?
> > 
> > Thanks for any help in advance!
> > Cheers!
> > Meino
> 
> It's not clear what you really want.  Why would you want USB audio
> without an actual USB audio device?  Without a USB audio
> dongle/device/whatever, what would you have to actually produce
> sound?I can imagine a "dummy" USB audio device - but I can imagine
> it for testing the software, but not actually producing any sound, so
> why would you want it?
> 
> Jack

As Jack said, a USB connector passes digital signals from your audio source 
(PC media player) to a USB connected device, which is able to convert the 
digital signals to analogue audio (DAC chip).  Without such a converter you 
wouldn't be able to hear sound coming out of whatever you connected to the USB 
port.

If you connect USB speakers, a soundbar, USB-C earphones and the like, they 
all have some DAC converter chip on them to turn the binary USB input into 
audible sound.  There's Class 1 and Class 2 USB audio devices.  Class 1 can 
process up to a maximum of 24-bit/96kHz files, while Class 2 can reach up to 
24-bit/192kHz - if you have this quality of audio files.

A dummy audio driver pretends it is an audio device for testing the audio on 
your PC, but it will not produce audio output.

I found this page explaining how USB audio works:

https://www.edn.com/design/consumer/4376143/Fundamentals-of-USB-Audio

-- 
Regards,
Mick

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Re: [gentoo-user] USB Audio ?

2019-05-13 Thread Jack

On 2019.05.13 23:10, tu...@posteo.de wrote:

Hi,

is it somehow possible to play USB-Audio on a PC without one of these
USB-dongle-"soundcards" (DACs)?

I searched the web and only got links to those dongles...

On the other hand: On the forum of the developers board one post
spokes of a "dummy" USB-Audio device...

How can I acchieve this?

Thanks for any help in advance!
Cheers!
Meino
It's not clear what you really want.  Why would you want USB audio  
without an actual USB audio device?  Without a USB audio  
dongle/device/whatever, what would you have to actually produce  
sound?I can imagine a "dummy" USB audio device - but I can imagine  
it for testing the software, but not actually producing any sound, so  
why would you want it?


Jack


[gentoo-user] USB Audio ?

2019-05-13 Thread tuxic
Hi,

is it somehow possible to play USB-Audio on a PC without one of these
USB-dongle-"soundcards" (DACs)?

I searched the web and only got links to those dongles...

On the other hand: On the forum of the developers board one post 
spokes of a "dummy" USB-Audio device...

How can I acchieve this?

Thanks for any help in advance!
Cheers!
Meino