sound over USB

[Subhashini Rao Beerisetty]

 Hi all,

In my Linux machine, I connected the plantronics usb headset with mic
and I see(with the help of dmesg) that this device detected.



[116676.507868] usb 2-2: new full-speed USB device number 5 using xhci_hcd
[116676.923445] usb 2-2: New USB device found, idVendor=047f, idProduct=c012
 [116676.927091] usb 2-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
 [116676.934252] usb 2-2: Product: Plantronics .Audio 628 USB
 [116676.941445] usb 2-2: Manufacturer: Plantronics
 [116676.945731] usb 2-2: ep 0x84 - rounding interval to 64
microframes, ep desc says 80 microframes
 [116677.078071] hidraw: raw HID events driver (C) Jiri Kosina
 [116677.159669] usbcore: registered new interface driver usbhid
 [116677.161686] usbhid: USB HID core driver
 [116677.175458] input: Plantronics Plantronics .Audio 628 USB as
/devices/pci0000:00/0000:00:14.0/usb2/2-2/2-2:1.3/0003:047F:C012.0001/input/input4
 [116677.234588] plantronics 0003:047F:C012.0001:
input,hiddev0,hidraw0: USB HID v1.00 Device [Plantronics Plantronics
.Audio 628 USB] on usb-0000:00:14.0-2/input3
 [116677.281756] usbcore: registered new interface driver snd-usb-audio

 The following nodes are present in the /dev/snd

$ ls -l /dev/snd/

total 0

drwxr-xr-x 2 root root       60 May 12 11:32 by-id

drwxr-xr-x 2 root root       60 May 12 11:32 by-path

crw-rw---- 1 root audio 116,  2 May 12 11:32 controlC1

crw-rw---- 1 root audio 116,  4 May 12 11:32 pcmC1D0c

crw-rw---- 1 root audio 116,  3 May 12 11:32 pcmC1D0p

crw-rw---- 1 root audio 116,  1 May 12 11:32 seq

crw-rw---- 1 root audio 116, 33 May 12 11:32 timer



What are all these devices present in /dev/snd

How do I use it for playing and recording an audio?

Basically first I want to gain knowledge on set of test cases I can
run on ALSA and then learn ALSA kernel modules stuff including
snd_usb_audio mdule.

So please guide me by providing related documentation/Steps.



Thanks,