Hi,
Speaker-webcam eMeet C980 Pro does not play, outputs only silent noise.
The digital volume seems to be down.
dmesg:
[22406.805176] input: HD Webcam eMeet C980 Pro: HD We as
/devices/pci0000:00/0000:00:01.2/0000:02:00.0/usb1/1-7/1-7.1/1-7.1:1.0/input/input27
[22406.829048] usb 1-7.1: current rate 16000 is different from the
runtime rate 48000
[22406.933044] usb 1-7.1: Warning! Unlikely big volume range (=10240),
cval->res is probably wrong.
[22406.933048] usb 1-7.1: [5] FU [PCM Playback Volume] ch = 1, val =
-7168/3072/1
[22407.001043] usb 1-7.1: Warning! Unlikely big volume range (=3072),
cval->res is probably wrong.
[22407.001047] usb 1-7.1: [6] FU [Headset Capture Volume] ch = 1, val =
-1536/1536/1
amixer contents:
.....
numid=3,iface=MIXER,name='PCM Playback Switch'
; type=BOOLEAN,access=rw------,values=1
: values=on
numid=4,iface=MIXER,name='PCM Playback Volume'
; type=INTEGER,access=rw---R--,values=1,min=0,max=10240,step=0
: values=10240
| dBminmax-min=-28.00dB,max=12.00dB
numid=5,iface=MIXER,name='Headset Capture Switch'
; type=BOOLEAN,access=rw------,values=1
: values=on
numid=6,iface=MIXER,name='Headset Capture Volume'
; type=INTEGER,access=rw---R--,values=1,min=0,max=3072,step=0
: values=3072
| dBminmax-min=-6.00dB,max=6.00dB
.....
I tried playing with csetting numid=4 to various values, no effect.
Please what should be the correct min,max,res in volume_control_quirks
for the 'PCM Playback Volume' control for such device?
Capture seems to be OK (maybe the range should be adjusted too for the
complete range of control)
Also, the device does not seem to get the current rate correctly, but
IIUC that should not have any adverse effect (not marked with
QUIRK_FLAG_GET_SAMPLE_RATE yet):
[22407.178045] usb 1-7.1: current rate 16000 is different from the
runtime rate 48000
[22407.199046] usb 1-7.1: current rate 16000 is different from the
runtime rate 48000
[22407.220045] usb 1-7.1: current rate 16000 is different from the
runtime rate 48000
[22407.282044] usb 1-7.1: current rate 16000 is different from the
runtime rate 48000
[22811.235851] usb 1-7.1: current rate 16000 is different from the
runtime rate 48000
[22829.335494] usb 1-7.1: current rate 16000 is different from the
runtime rate 48000
cat /proc/asound/card2/stream0
SHENZHEN EMEET TECHNOLOGY CO., LTD. HD Webcam eMeet C980 Pro at
usb-0000:02:00. : USB Audio
Playback:
Status: Stop
Interface 3
Altset 1
Format: S16_LE
Channels: 1
Endpoint: 0x01 (1 OUT) (ADAPTIVE)
Rates: 48000
Data packet interval: 1000 us
Bits: 16
Channel map: FL
Capture:
Status: Stop
Interface 4
Altset 1
Format: S16_LE
Channels: 1
Endpoint: 0x83 (3 IN) (SYNC)
Rates: 16000
Data packet interval: 1000 us
Bits: 16
alsa-info dump:
http://alsa-project.org/db/?f=7af42635d88e858818932578aa8445810916a947
lsusb -v -d 328f:1912 attached.
Thank you very much for any hints.
Best regards,
Pavel.
Bus 001 Device 012: ID 328f:1912
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x328f
idProduct 0x1912
bcdDevice 1.60
iManufacturer 1 SHENZHEN EMEET TECHNOLOGY CO., LTD.
iProduct 2 HD Webcam eMeet C980 Pro
iSerial 3 Ucamera002
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x03c4
bNumInterfaces 5
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 500mA
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 0
bInterfaceCount 2
bFunctionClass 14 Video
bFunctionSubClass 3 Video Interface Collection
bFunctionProtocol 0
iFunction 4 HD Webcam eMeet C980 Pro
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 1 Video Control
bInterfaceProtocol 0
iInterface 4 HD Webcam eMeet C980 Pro
VideoControl Interface Descriptor:
bLength 13
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdUVC 1.00
wTotalLength 0x0033
dwClockFrequency 48.000000MHz
bInCollection 1
baInterfaceNr( 0) 1
VideoControl Interface Descriptor:
bLength 18
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0201 Camera Sensor
bAssocTerminal 0
iTerminal 0
wObjectiveFocalLengthMin 0
wObjectiveFocalLengthMax 0
wOcularFocalLength 0
bControlSize 3
bmControls 0x00000002
Auto-Exposure Mode
VideoControl Interface Descriptor:
bLength 11
bDescriptorType 36
bDescriptorSubtype 5 (PROCESSING_UNIT)
Warning: Descriptor too short
bUnitID 2
bSourceID 1
wMaxMultiplier 16384
bControlSize 2
bmControls 0x0000177f
Brightness
Contrast
Hue
Saturation
Sharpness
Gamma
White Balance Temperature
Backlight Compensation
Gain
Power Line Frequency
White Balance Temperature, Auto
iProcessing 0
bmVideoStandards 0x09
None
SECAM - 625/50
VideoControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 3
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 2
iTerminal 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 bytes
bInterval 8
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
VideoStreaming Interface Descriptor:
bLength 15
bDescriptorType 36
bDescriptorSubtype 1 (INPUT_HEADER)
bNumFormats 2
wTotalLength 0x0293
bEndPointAddress 130
bmInfo 0
bTerminalLink 3
bStillCaptureMethod 0
bTriggerSupport 0
bTriggerUsage 0
bControlSize 1
bmaControls( 0) 0
bmaControls( 1) 4
VideoStreaming Interface Descriptor:
bLength 11
bDescriptorType 36
bDescriptorSubtype 6 (FORMAT_MJPEG)
bFormatIndex 1
bNumFrameDescriptors 10
bFlags 0
Fixed-size samples: No
bDefaultFrameIndex 1
bAspectRatioX 0
bAspectRatioY 0
bmInterlaceFlags 0x00
Interlaced stream or variable: No
Fields per frame: 1 fields
Field 1 first: No
Field pattern: Field 1 only
bCopyProtect 0
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 1
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 480
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 2
bmCapabilities 0x00
Still image unsupported
wWidth 352
wHeight 288
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 3
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 360
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 4
bmCapabilities 0x00
Still image unsupported
wWidth 160
wHeight 120
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 5
bmCapabilities 0x00
Still image unsupported
wWidth 800
wHeight 600
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 6
bmCapabilities 0x00
Still image unsupported
wWidth 960
wHeight 720
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 7
bmCapabilities 0x00
Still image unsupported
wWidth 1024
wHeight 576
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 8
bmCapabilities 0x00
Still image unsupported
wWidth 1280
wHeight 720
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 9
bmCapabilities 0x00
Still image unsupported
wWidth 1600
wHeight 896
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 10
bmCapabilities 0x00
Still image unsupported
wWidth 1920
wHeight 1080
dwMinBitRate 7372800
dwMaxBitRate 7372800
dwMaxVideoFrameBufferSize 460800
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 27
bDescriptorType 36
bDescriptorSubtype 4 (FORMAT_UNCOMPRESSED)
bFormatIndex 2
bNumFrameDescriptors 10
guidFormat {32595559-0000-0010-8000-00aa00389b71}
bBitsPerPixel 16
bDefaultFrameIndex 1
bAspectRatioX 0
bAspectRatioY 0
bmInterlaceFlags 0x00
Interlaced stream or variable: No
Fields per frame: 2 fields
Field 1 first: No
Field pattern: Field 1 only
bCopyProtect 0
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 1
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 480
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 2
bmCapabilities 0x00
Still image unsupported
wWidth 352
wHeight 288
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 3
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 360
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 4
bmCapabilities 0x00
Still image unsupported
wWidth 160
wHeight 120
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 5
bmCapabilities 0x00
Still image unsupported
wWidth 800
wHeight 600
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 999999
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 6
bmCapabilities 0x00
Still image unsupported
wWidth 960
wHeight 720
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 999999
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 7
bmCapabilities 0x00
Still image unsupported
wWidth 1024
wHeight 576
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 999999
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 8
bmCapabilities 0x00
Still image unsupported
wWidth 1280
wHeight 720
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 1999998
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 9
bmCapabilities 0x00
Still image unsupported
wWidth 1600
wHeight 896
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 1999998
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 10
bmCapabilities 0x00
Still image unsupported
wWidth 1920
wHeight 1080
dwMinBitRate 29491200
dwMaxBitRate 29491200
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 333333
bFrameIntervalType 1
dwFrameInterval( 0) 1999998
VideoStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 13 (COLORFORMAT)
bColorPrimaries 1 (BT.709,sRGB)
bTransferCharacteristics 1 (BT.709)
bMatrixCoefficients 4 (SMPTE 170M (BT.601))
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0400 1x 1024 bytes
bInterval 1
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 2
bInterfaceCount 3
bFunctionClass 1 Audio
bFunctionSubClass 0
bFunctionProtocol 0
iFunction 5 HD Webcam eMeet C980 Pro
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 1 Control Device
bInterfaceProtocol 0
iInterface 5 HD Webcam eMeet C980 Pro
AudioControl Interface Descriptor:
bLength 10
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 0x0046
bInCollection 2
baInterfaceNr(0) 3
baInterfaceNr(1) 4
AudioControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bNrChannels 1
wChannelConfig 0x0003
Left Front (L)
Right Front (R)
iChannelNames 0
iTerminal 0
AudioControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 2
wTerminalType 0x0405 Echo-canceling speakerphone
bAssocTerminal 0
bNrChannels 1
wChannelConfig 0x0003
Left Front (L)
Right Front (R)
iChannelNames 0
iTerminal 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 3
wTerminalType 0x0405 Echo-canceling speakerphone
bAssocTerminal 0
bSourceID 5
iTerminal 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 4
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 6
iTerminal 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 6 (FEATURE_UNIT)
bUnitID 5
bSourceID 1
bControlSize 2
bmaControls(0) 0x0003
Mute Control
Volume Control
iFeature 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 6 (FEATURE_UNIT)
bUnitID 6
bSourceID 2
bControlSize 2
bmaControls(0) 0x0003
Mute Control
Volume Control
iFeature 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
AudioStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (AS_GENERAL)
bTerminalLink 1
bDelay 1 frames
wFormatTag 0x0001 PCM
AudioStreaming Interface Descriptor:
bLength 11
bDescriptorType 36
bDescriptorSubtype 2 (FORMAT_TYPE)
bFormatType 1 (FORMAT_TYPE_I)
bNrChannels 1
bSubframeSize 2
bBitResolution 16
bSamFreqType 1 Discrete
tSamFreq[ 0] 48000
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 9
Transfer Type Isochronous
Synch Type Adaptive
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 4
bRefresh 0
bSynchAddress 0
AudioStreaming Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 1 Milliseconds
wLockDelay 0x0001
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 4
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 4
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
AudioStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (AS_GENERAL)
bTerminalLink 4
bDelay 1 frames
wFormatTag 0x0001 PCM
AudioStreaming Interface Descriptor:
bLength 11
bDescriptorType 36
bDescriptorSubtype 2 (FORMAT_TYPE)
bFormatType 1 (FORMAT_TYPE_I)
bNrChannels 1
bSubframeSize 2
bBitResolution 16
bSamFreqType 1 Discrete
tSamFreq[ 0] 16000
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 13
Transfer Type Isochronous
Synch Type Synchronous
Usage Type Data
wMaxPacketSize 0x0180 1x 384 bytes
bInterval 4
bRefresh 0
bSynchAddress 0
AudioStreaming Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 1 Milliseconds
wLockDelay 0x0001
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0001
Self Powered