Difference between revisions of "Stk1160 based USB 2.0 video and audio capture devices"

From LinuxTVWiki
Jump to: navigation, search
(stk1160 limitations)
(8 intermediate revisions by one user not shown)
Line 13: Line 13:
 
===Components Used===
 
===Components Used===
 
* Syntek STK1160 (USB video bridge)
 
* Syntek STK1160 (USB video bridge)
* [http://www.silan.com.cn/english/product/ProductItemDetail.aspx?id=18&pid=20090706092630633824691909652010&c=%E8%A7%86%E9%A2%91%E7%94%B5%E8%B7%AF Silan SC8113] (Philips SAA7113 compatible video decoder)
+
* [http://www.silan.com.cn/english/product/ProductItemDetail.aspx?id=18&pid=20090706092630633824691909652010&c=%E8%A7%86%E9%A2%91%E7%94%B5%E8%B7%AF Silan SC8113] or GM7113 (Philips SAA7113 compatible video decoder chips)
* AC'97 audio processor (from different manufacturers. In models where this chip is missing audio capturing is done by the STK1160 chips built-in ADC for mono microphone audio recording.)  
+
* AC'97 audio processor (from different manufacturers. In models where this chip is missing (2 chip stk1160 Easycaps) audio capturing is done by the STK1160 chips built-in 8 bit ADC for mono microphone audio recording.)  
  
 
===Other Images===
 
===Other Images===
Line 36: Line 36:
  
 
* 48000 = Model with AC'97 chip
 
* 48000 = Model with AC'97 chip
* 8000 = Model without AC'97 chip  
+
* 8000 = Model without AC'97 chip (currently not supported by the stk1160 driver)
  
If you encounter audio problems while capturing you need to specify the correct audiorate of your model in the capturing program.
 
  
 
==Making it Work==
 
==Making it Work==
Line 44: Line 43:
  
 
===Drivers===
 
===Drivers===
==== eaysycap driver ====
 
The easycap driver is part of the current kernel (since 2.6.38) and supports all the features of the STK1160 based devices but has some limitations (framedropping, stability, sound issues).
 
  
===== easycap audio support =====
+
==== stk1160 driver ====
 +
The stk1160 driver is in the mainline kernel since version 3.7. It is the successor of the legacy easycap driver (see below).
  
The easycap module creates an additional ALSA soundcard '''EasyALSA0'''.
+
The stk1160 module supports:
 +
* V4L2 video capturing
 +
* audio capturing via ALSA (only the 48000Hz Easycap is supported)
  
Often when the STK1160 device is plugged in the '''snd_usb_audio''' module conflicts with the easycap module and the EasyALSA0 soundcard is not created. As a workaround you need to unplug the device, unload the module (rmmod snd_usb_audio) and then plug in the device again.
+
====== Enable sound capture  ======
  
==== stk1160 driver ====
+
The stk1160 module registers a control-only alsa soundcard. This sound card is called '''stk1160-mixer'''.
The stk1160 driver is the successor of the easycap driver. It supports video capturing and audio capturing via ALSA. This driver doesn't suffer from the limitations of the easycap driver but is still under development. It is intended that the stk1160 module will replace the easycap module in the 3.7 kernel release.
+
The real sound capture is done through the '''Controlle''' soundcard which is created after plugging in the STK1160 device by the '''snd_usb_audio''' module.
 +
 
 +
On a fresh installed system, or if you have installed the driver by yourself, you once (!) need to enable sound capture from '''stk1160-mixer''' in the mixer settings.
 +
 
 +
To enable sound capture you have to select in alsamixer the '''Line''' item on the capture menu for stk1160-mixer when the STK1160 device is plugged in:
 +
You can do this in the terminal as well with this command:
 +
 
 +
# amixer -c stk1160mixer sset Line unmute cap
 +
 
 +
Note! In the viewing- or capturing program you must then select the '''Controlle''' soundcard or its number to hear sound!
 +
 
 +
===== Limitations  =====
 +
 
 +
====== AC'97 audio only ======
 +
 
 +
The stk1160 module only supports audio capturing from the CVBS + S-Video Easycap with builtin AC'97 chip (3 chip stk1160 Easycap; 48000Hz model). Adding support for the 8 bit ADC in the stk1160 chip is planned in the future.
 +
 
 +
If you have the 4 CVBS model or the CVBS + S-Video model without AC'97 chip the dmesg messages look like this:
 +
# dmesg
 +
[12677.625434] usb 2-2: new high-speed USB device number 8 using ehci-pci
 +
[12677.740513] usb 2-2: New device Syntek Semiconductor USB 2.0 Video
 +
Capture Controller @ 480 Mbps (05e1:0408, interface 0, class 0)
 +
[12677.740517] usb 2-2: video interface 0 found
 +
[12678.217418] stk1160: driver ver 0.9.5 successfully loaded
 +
[12678.220618] '''AC'97 0 access is not valid [0x0], removing mixer.'''
 +
[12678.220623] stk1160: registers to NTSC like standard
 +
[12678.221681] stk1160 2-2:1.0: V4L2 device registered as video1
 +
In this case you maybe can get some crappy sound through the '''Controlle''' soundcard created by the '''snd_usb_audio''' module, but if you want to capture hight quality sound you need to plug in the audio source to the Line in plug of your built-in soundcard. (You only need to change the number of the sound device in the capturing program if you want to watch/ record video with sound.)
 +
 
 +
====== Framescaling is not supported  ======
 +
 
 +
Unlike the legacy easycapdriver the stk1160 driver doesn't support framescaling.
 +
This is important for some programs where setting width and height of the video stream (e.g. Zonemeinder) is necessary. Other settings than 720x576 PAL or 720x480 NTSC may cause proplems with those programs.
 +
 
 +
====== Known issue ======
 +
 
 +
Easycap devices which have the gm7113 video decoder chip (saa7113 clone) inside don't work on stk1160 but do work
 +
on the legacy easycap driver. This issue will be solved in kernel 3.11 (expected).
 +
 
 +
===== Sourcecode =====
 +
 
 +
If you want to use the stk1160 driver under previous kernels (3.2, 3.4 or 3.6 kernel only !), you can get the sourcecode frome here:
  
 
[https://github.com/ezequielgarcia/stk1160-standalone stk1160 github repository]
 
[https://github.com/ezequielgarcia/stk1160-standalone stk1160 github repository]
  
[https://github.com/ezequielgarcia/stk1160-standalone/zipball/for_v3.2 stk1160 sourcecode-zipball for kernel 3.2]
+
Select the svideo2_for_3.2 version if you want to use the s-video input of yout stk1160 device.
  
 
[http://easycap.blogspot.co.at/2012/07/new-driver-for-easycap-dc60-stk1160.html Additional installation instructions]
 
[http://easycap.blogspot.co.at/2012/07/new-driver-for-easycap-dc60-stk1160.html Additional installation instructions]
  
===== stk1160 audio support =====
 
  
The stk1160 module registers a control-only alsa soundcard. This sound card is called '''stk1160-mixer'''.
 
The real sound capture is done through the '''Controlle''' soundcard which is created after plugging in the STK1160 device by the snd_usb_audio module.
 
  
To enable sound capture you have to select in alsamixer the 'Line' item on the capture menu for stk1160-mixer when the STK1160 device is plugged in:
+
==== legacy easycap driver ====
You can do this in the terminal as well with this command:
+
The easycap driver is part of the kernel from  2.6.38 up to 3.6.x and supports all the features of the STK1160 based devices but has some limitations (framedropping, stability, sound issues).
  
# amixer -c stk1160mixer sset Line unmute cap
+
===== easycap audio support =====
 +
 
 +
The eascap module supports audio from the 48000Hz and the 8000Hz models.
 +
 
 +
The easycap module creates an additional ALSA soundcard '''EasyALSA0'''.
 +
 
 +
Often when the STK1160 device is plugged in the '''snd_usb_audio''' module conflicts with the easycap module and the EasyALSA0 soundcard is not created. As a workaround you need to unplug the device, unload the module (rmmod snd_usb_audio) and then plug in the device again.
  
Note! In the viewing- or capturing program you must then select the 'Controlle' soundcard or its number to hear sound!
+
If you encounter audio problems while capturing you need to specify the correct audiorate of your model (48000 or 8000) in the capturing program.
  
 
===Sample Kernel Output===
 
===Sample Kernel Output===
Line 167: Line 211:
 
At the middle of 2012 [https://github.com/ezequielgarcia/stk1160-standalone Ezequiel Garcia] decided to rework the easycapdriver. He changed the drivers name to "stk1160".  
 
At the middle of 2012 [https://github.com/ezequielgarcia/stk1160-standalone Ezequiel Garcia] decided to rework the easycapdriver. He changed the drivers name to "stk1160".  
  
In the 3.7 kernel release the old easycapdriver has been replaced by the stk1160 driver.
+
In the 3.7 kernel release the legacy easycapdriver has been replaced by the stk1160 driver.
  
  

Revision as of 09:02, 16 June 2013

This article covers all the tunerless USB 2.0 video and audio capture devices which are based on the STK1160 chip from Syntec Semiconductor.co.ltd.. This device is convenient for capturing from cameras, VHS-tapes, receivers ... and even for small surveillance installation (4 inputs model).

Many but not all of these devices are branded as Easycap. Althought this device is sold with different names and labels, in many forums and blogs this device is called "EasyCAP DC60".

Overview/Features

  • USB ID 05e1:0408
  • USB 2.0 interface (USB 1.1 will not work, it's too slow).
  • Video capturing up to 720x576px @ 25fps (PAL) and 720x480px @ 30fps (NTSC)
  • Inputs: (Model 001) CVBS, S-VIDEO, AUDIO(L), AUDIO(R)
  • Inputs: (Model 002) 4 yellow input cables (CVBS) labelled 1, 2, 3, 4 and one white unlabelled audio cable
  • Audioquality: Model 001 has AC'97 audio (48000 Hz samplerate), model 002 (and some models 001 where the AC'97 chip is missing) has mono microphone audio (8000 Hz samplerate).

Components Used

  • Syntek STK1160 (USB video bridge)
  • Silan SC8113 or GM7113 (Philips SAA7113 compatible video decoder chips)
  • AC'97 audio processor (from different manufacturers. In models where this chip is missing (2 chip stk1160 Easycaps) audio capturing is done by the STK1160 chips built-in 8 bit ADC for mono microphone audio recording.)

Other Images

Identification

# lsusb
Bus 001 Device 003: ID 05e1:0408 Syntek Semiconductor Co., Ltd STK1160 Video Capture Device

lsusb -v see below

Identify the audiotype of your device

The following shell command reports the audiorate (sampling frequency) of your STK1160 based device:

lsusb -v -d 05e1:0408 | grep tSamFreq | sed -e "s,^.* ,,"
  • 48000 = Model with AC'97 chip
  • 8000 = Model without AC'97 chip (currently not supported by the stk1160 driver)


Making it Work

STK1160 based devices ar supported under Linux since kernel 2.6.38

Drivers

stk1160 driver

The stk1160 driver is in the mainline kernel since version 3.7. It is the successor of the legacy easycap driver (see below).

The stk1160 module supports:

  • V4L2 video capturing
  • audio capturing via ALSA (only the 48000Hz Easycap is supported)
Enable sound capture

The stk1160 module registers a control-only alsa soundcard. This sound card is called stk1160-mixer. The real sound capture is done through the Controlle soundcard which is created after plugging in the STK1160 device by the snd_usb_audio module.

On a fresh installed system, or if you have installed the driver by yourself, you once (!) need to enable sound capture from stk1160-mixer in the mixer settings.

To enable sound capture you have to select in alsamixer the Line item on the capture menu for stk1160-mixer when the STK1160 device is plugged in: You can do this in the terminal as well with this command:

# amixer -c stk1160mixer sset Line unmute cap 

Note! In the viewing- or capturing program you must then select the Controlle soundcard or its number to hear sound!

Limitations
AC'97 audio only

The stk1160 module only supports audio capturing from the CVBS + S-Video Easycap with builtin AC'97 chip (3 chip stk1160 Easycap; 48000Hz model). Adding support for the 8 bit ADC in the stk1160 chip is planned in the future.

If you have the 4 CVBS model or the CVBS + S-Video model without AC'97 chip the dmesg messages look like this:

# dmesg 
[12677.625434] usb 2-2: new high-speed USB device number 8 using ehci-pci
[12677.740513] usb 2-2: New device Syntek Semiconductor USB 2.0 Video
Capture Controller @ 480 Mbps (05e1:0408, interface 0, class 0)
[12677.740517] usb 2-2: video interface 0 found
[12678.217418] stk1160: driver ver 0.9.5 successfully loaded
[12678.220618] AC'97 0 access is not valid [0x0], removing mixer.
[12678.220623] stk1160: registers to NTSC like standard
[12678.221681] stk1160 2-2:1.0: V4L2 device registered as video1

In this case you maybe can get some crappy sound through the Controlle soundcard created by the snd_usb_audio module, but if you want to capture hight quality sound you need to plug in the audio source to the Line in plug of your built-in soundcard. (You only need to change the number of the sound device in the capturing program if you want to watch/ record video with sound.)

Framescaling is not supported

Unlike the legacy easycapdriver the stk1160 driver doesn't support framescaling. This is important for some programs where setting width and height of the video stream (e.g. Zonemeinder) is necessary. Other settings than 720x576 PAL or 720x480 NTSC may cause proplems with those programs.

Known issue

Easycap devices which have the gm7113 video decoder chip (saa7113 clone) inside don't work on stk1160 but do work on the legacy easycap driver. This issue will be solved in kernel 3.11 (expected).

Sourcecode

If you want to use the stk1160 driver under previous kernels (3.2, 3.4 or 3.6 kernel only !), you can get the sourcecode frome here:

stk1160 github repository

Select the svideo2_for_3.2 version if you want to use the s-video input of yout stk1160 device.

Additional installation instructions


legacy easycap driver

The easycap driver is part of the kernel from 2.6.38 up to 3.6.x and supports all the features of the STK1160 based devices but has some limitations (framedropping, stability, sound issues).

easycap audio support

The eascap module supports audio from the 48000Hz and the 8000Hz models.

The easycap module creates an additional ALSA soundcard EasyALSA0.

Often when the STK1160 device is plugged in the snd_usb_audio module conflicts with the easycap module and the EasyALSA0 soundcard is not created. As a workaround you need to unplug the device, unload the module (rmmod snd_usb_audio) and then plug in the device again.

If you encounter audio problems while capturing you need to specify the correct audiorate of your model (48000 or 8000) in the capturing program.

Sample Kernel Output

easycap module

# dmesg 
[  250.728092] usb 1-2: new high speed USB device number 4 using ehci_hcd
[  254.681355] easycap::0adjust_standard: selected standard: PAL_BGHIN
[  254.992254] easycap::0adjust_format: sought:    640x480,UYVY(0x59565955),1=field,0x00=std mask
[  254.992263] easycap::0adjust_format: sought:    V4L2_FIELD_NONE
[  254.992273] easycap::0adjust_format: actioning: 640x480 PAL_BGHIN_AT_640x480_FMT_UYVY-n
[  255.016137] easycap::0adjust_brightness: adjusting brightness to  0x7F
[  255.040149] easycap::0adjust_contrast: adjusting contrast to  0x3F
[  255.064162] easycap::0adjust_saturation: adjusting saturation to  0x2F
[  255.088173] easycap::0adjust_hue: adjusting hue to  0x00
[  255.089557] easycap::0easycap_usb_probe: registered with videodev: 0=minor
[  255.089565] easycap::0easycap_usb_probe: ends successfully for interface 0
[  255.089713] easycap::0easycap_usb_probe: ends successfully for interface 1
[  255.090017] easycap::0easycap_usb_probe: audio hardware is AC'97
[  255.090485] easycap::0easycap_alsa_probe: registered EasyALSA0
[  255.090492] easycap::0easycap_usb_probe: ends successfully for interface 2
[  255.091910] easycap:: easycap_open: ==========OPEN=========
[  255.161078] easycap::0audio_setup: 0x414C:0x4760 is audio vendor id
[  255.181331] easycap::0audio_setup: 0x414C:0x4760 is audio vendor id
[  255.263624] easycap::0audio_setup: 0x414C:0x4760 is audio vendor id
[  255.345927] easycap::0audio_setup: 0x414C:0x4760 is audio vendor id
[  255.432975] easycap::0audio_setup: 0x414C:0x4760 is audio vendor id
[  255.525395] easycap::0audio_setup: 0x414C:0x4760 is audio vendor id
[  255.631195] snd_pcm_update_hw_ptr0: 24 callbacks suppressed
[  256.341308] easycap::0adjust_standard: selected standard: PAL_BGHIN
[  256.652338] easycap::0adjust_format: sought:    640x480,UYVY(0x59565955),1=field,0x00=std mask
[  256.652346] easycap::0adjust_format: sought:    V4L2_FIELD_NONE
[  256.652355] easycap::0adjust_format: actioning: 640x480 PAL_BGHIN_AT_640x480_FMT_UYVY-n
[  256.676218] easycap::0adjust_brightness: adjusting brightness to  0x7F
[  256.700233] easycap::0adjust_contrast: adjusting contrast to  0x3F
[  256.724242] easycap::0adjust_saturation: adjusting saturation to  0x2F
[  256.748129] easycap::0adjust_hue: adjusting hue to  0x00 

stk1160 module

# dmesg
[16873.944081] usb 1-2: new high-speed USB device number 2 using ehci_hcd
[16874.892446] Linux video capture interface: v2.00
[16875.012940] usb 1-2: New device Syntek Semiconductor USB 2.0 Video Capture Controller @ 480 Mbps (05e1:0408, interface 0, class 0)
[16875.012949] usb 1-2: video interface 0 found
[16875.836259] saa7115 14-0025: saa7113 found (1f7113d0e100000) @ 0x4a (stk1160)
[16877.372155] stk1160: driver ver 0.9.3 successfully loaded
[16877.469999] stk1160: registers to NTSC like standard
[16877.792436] stk1160 1-2:1.0: V4L2 device registered as video0
[16877.793733] usbcore: registered new interface driver snd-usb-audio
[16877.795409] usbcore: registered new interface driver stk1160


Usage

The STK1160 device needs a USB 2.0 capable USB port. USB 1.1 will not work (it's too slow).

The driver for the STK1160 device creates a /dev/videoN node and an ALSA soundcard, The different video-inputs of the device can be accessed by their inputnumber (starting at 0).
From the two or four video cables on the device only one (!) can be used at the same time. If you want to switch through the different inputs of your card you need to start the capturing program again with the next input number.

In the viewing/ capturing program (e.g. mplayer) you must specify

  • the videodevicenode of the STK1160 card (/dev/videoN),
  • the input number of the cable where the source is plugged in,
  • the TV norm of the videosource and (e.g. PAL, NTSC)
  • the ALSA sounddevice if you want to capture audio. Get a list of ALSA soundcards with this command:
# cat /proc/asound/cards

If you encounter audio problems while capturing you need to specify the correct audiorate of your model in the capturing program.

Example for mplayer

Assumed that your STK1160 device is the second videodevice (the first is your webcam) and the second soundcard on your system, and that on the first CVBS input a PAL camera is plugged in and sound also comes from the STK1160 device, the mplayer command for viewing would look like this:

mplayer tv:// -tv driver=v4l2:norm=PAL:width=720:height=576:outfmt=uyvy:device=/dev/video1:input=0:\
alsa:adevice=hw.1:audiorate=48000:forceaudio:immediatemode=0 -ao sdl

More programs

These programs are known to be useful for analogue audio- and videocapturing with STK1160 based (and similar) devices.

  • qv4l2 - useful for testing
  • mplayer and mencoder
  • mtvcgui - Python GUI for mplayer and mencoder
  • VLC
  • TVtime
  • avconv (libav; formerly ffmpeg)
  • Zoneminder - Linux surveillance suite
  • Any other program which is capable of analogue video- and audiocapturing will probably work with STK1160 devices.


Short linux driver history

In early 2010 Mike Thomas started developing a driver for the STK1160 based video capture device which is sold as EasyCAP DC60. He used the stk11xx driver and some existing patches for the "05e1:0408" Syntek device as a basis for his project. Since the easycapdriver (version 0.9) has been added to the staging directory of the Linux kernel in November 2011 Mike Thomas stopped his development and support.

Some people added changes in order to clean up the sourcecode. These changes didn't hardly affect the limitations (framedropping, stability) of the driver.

At the middle of 2012 Ezequiel Garcia decided to rework the easycapdriver. He changed the drivers name to "stk1160".

In the 3.7 kernel release the legacy easycapdriver has been replaced by the stk1160 driver.


External Links


Full lsusb -v output

The following lsusb -v output is from the STK1160 based model 001 with builtin AC'97 audio processor:

# lsusb -v
Bus 001 Device 002: ID 05e1:0408 Syntek Semiconductor Co., Ltd STK1160 Video Capture Device
Couldn't open device, some information will be missing
Device Descriptor:
 bLength                18
 bDescriptorType         1
 bcdUSB               2.00
 bDeviceClass            0 (Defined at Interface level)
 bDeviceSubClass         0 
 bDeviceProtocol         0 
 bMaxPacketSize0        64
 idVendor           0x05e1 Syntek Semiconductor Co., Ltd
 idProduct          0x0408 STK1160 Video Capture Device
 bcdDevice            0.05
 iManufacturer           1 
 iProduct                2 
 iSerial                 0 
 bNumConfigurations      1
 Configuration Descriptor:
   bLength                 9
   bDescriptorType         2
   wTotalLength          251
   bNumInterfaces          3
   bConfigurationValue     1
   iConfiguration          0 
   bmAttributes         0x80
     (Bus Powered)
   MaxPower              500mA
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        0
     bAlternateSetting       0
     bNumEndpoints           2
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0 
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x81  EP 1 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0000  1x 0 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x82  EP 2 IN
       bmAttributes            1
         Transfer Type            Isochronous
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0000  1x 0 bytes
       bInterval               1
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        0
     bAlternateSetting       1
     bNumEndpoints           2
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0 
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x81  EP 1 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0002  1x 2 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x82  EP 2 IN
       bmAttributes            1
         Transfer Type            Isochronous
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0300  1x 768 bytes
       bInterval               1
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        0
     bAlternateSetting       2
     bNumEndpoints           2
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0 
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x81  EP 1 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0002  1x 2 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x82  EP 2 IN
       bmAttributes            1
         Transfer Type            Isochronous
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x03fc  1x 1020 bytes
       bInterval               1
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        0
     bAlternateSetting       3
     bNumEndpoints           2
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0 
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x81  EP 1 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0002  1x 2 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x82  EP 2 IN
       bmAttributes            1
         Transfer Type            Isochronous
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0400  1x 1024 bytes
       bInterval               1
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        0
     bAlternateSetting       4
     bNumEndpoints           2
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0 
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x81  EP 1 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0002  1x 2 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x82  EP 2 IN
       bmAttributes            1
         Transfer Type            Isochronous
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0c00  2x 1024 bytes
       bInterval               1
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        0
     bAlternateSetting       5
     bNumEndpoints           2
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0 
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x81  EP 1 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0002  1x 2 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x82  EP 2 IN
       bmAttributes            1
         Transfer Type            Isochronous
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x1400  3x 1024 bytes
       bInterval               1
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        1
     bAlternateSetting       0
     bNumEndpoints           0
     bInterfaceClass         1 Audio
     bInterfaceSubClass      1 Control Device
     bInterfaceProtocol      0 
     iInterface             11 
     AudioControl Interface Descriptor:
       bLength                 9
       bDescriptorType        36
       bDescriptorSubtype      1 (HEADER)
       bcdADC               1.00
       wTotalLength           38
       bInCollection           1
       baInterfaceNr( 0)       2
     AudioControl Interface Descriptor:
       bLength                12
       bDescriptorType        36
       bDescriptorSubtype      2 (INPUT_TERMINAL)
       bTerminalID             1
       wTerminalType      0x0602 Digital Audio Interface
       bAssocTerminal          0
       bNrChannels             2
       wChannelConfig     0x0003
         Left Front (L)
         Right Front (R)
       iChannelNames           0 
       iTerminal               0 
     AudioControl Interface Descriptor:
       bLength                 9
       bDescriptorType        36
       bDescriptorSubtype      3 (OUTPUT_TERMINAL)
       bTerminalID             2
       wTerminalType      0x0101 USB Streaming
       bAssocTerminal          0
       bSourceID               3
       iTerminal               0 
     AudioControl Interface Descriptor:
       bLength                 8
       bDescriptorType        36
       bDescriptorSubtype      6 (FEATURE_UNIT)
       bUnitID                 3
       bSourceID               1
       bControlSize            1
       bmaControls( 0)      0x01
         Mute Control
       iFeature                0 
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        2
     bAlternateSetting       0
     bNumEndpoints           1
     bInterfaceClass         1 Audio
     bInterfaceSubClass      2 Streaming
     bInterfaceProtocol      0 
     iInterface             11 
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x84  EP 4 IN
       bmAttributes            5
         Transfer Type            Isochronous
         Synch Type               Asynchronous
         Usage Type               Data
       wMaxPacketSize     0x0000  1x 0 bytes
       bInterval               1
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        2
     bAlternateSetting       1
     bNumEndpoints           1
     bInterfaceClass         1 Audio
     bInterfaceSubClass      2 Streaming
     bInterfaceProtocol      0 
     iInterface             11 
     AudioStreaming Interface Descriptor:
       bLength                 7
       bDescriptorType        36
       bDescriptorSubtype      1 (AS_GENERAL)
       bTerminalLink           2
       bDelay                  1 frames
       wFormatTag              1 PCM
     AudioStreaming Interface Descriptor:
       bLength                11
       bDescriptorType        36
       bDescriptorSubtype      2 (FORMAT_TYPE)
       bFormatType             1 (FORMAT_TYPE_I)
       bNrChannels             2
       bSubframeSize           2
       bBitResolution         16
       bSamFreqType            1 Discrete
       tSamFreq[ 0]        48000
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x84  EP 4 IN
       bmAttributes            5
         Transfer Type            Isochronous
         Synch Type               Asynchronous
         Usage Type               Data
       wMaxPacketSize     0x0100  1x 256 bytes
       bInterval               4
       AudioControl Endpoint Descriptor:
         bLength                 7
         bDescriptorType        37
         bDescriptorSubtype      1 (EP_GENERAL)
         bmAttributes         0x00
         bLockDelayUnits         0 Undefined
         wLockDelay              0 Undefined