When I plug one USB camera(046d:0893 as bellow), it displays two devices(/dev/video8 and /dev/video9).But only the device /dev/video8 can be captured in OpenCV function. So how could I know which to choose to capture?
lsusb:
Bus 002 Device 003: ID 2c7c:0800 Quectel Wireless Solutions Co., Ltd. Logitech StreamCam
Bus 002 Device 002: ID 1d5c:5001 Fresco Logic USB3.0 Hub
Bus 002 Device 006: ID 046d:0893 Logitech, Inc. Logitech StreamCam
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 1d5c:5011 Fresco Logic USB2.0 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
v4l2-ctl --list-devices:
NVIDIA Tegra Video Input Device (platform:tegra-camrtc-ca):
/dev/media0
vi-output, twgmsl 30-0028 (platform:tegra-capture-vi:0):
/dev/video0
/dev/video1
vi-output, twgmsl 31-0028 (platform:tegra-capture-vi:2):
/dev/video2
/dev/video3
vi-output, twgmsl 32-0028 (platform:tegra-capture-vi:4):
/dev/video4
/dev/video5
vi-output, twgmsl 33-0028 (platform:tegra-capture-vi:5):
/dev/video6
/dev/video7
Logitech StreamCam (usb-3610000.xhci-1):
/dev/video8
/dev/video9
/dev/media1
v4l2-ctl -d /dev/video8 --all
Driver Info:
Driver name : uvcvideo
Card type : Logitech StreamCam
Bus info : usb-3610000.xhci-1
Driver version : 5.10.104
Capabilities : 0x84a00001
Video Capture
Metadata Capture
Streaming
Extended Pix Format
Device Capabilities
Device Caps : 0x04200001
Video Capture
Streaming
Extended Pix Format
Media Driver Info:
Driver name : uvcvideo
Model : Logitech StreamCam
Serial : 45231985
Bus info : usb-3610000.xhci-1
Media version : 5.10.104
Hardware revision: 0x00000317 (791)
Driver version : 5.10.104
Interface Info:
ID : 0x03000002
Type : V4L Video
Entity Info:
ID : 0x00000001 (1)
Name : Logitech StreamCam
Function : V4L2 I/O
Flags : default
Pad 0x01000007 : 0: Sink
Link 0x0200001f: from remote pad 0x100000a of entity 'Processing 3': Data, Enabled, Immutable
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
Width/Height : 1920/1080
Pixel Format : 'YUYV' (YUYV 4:2:2)
Field : None
Bytes per Line : 3840
Size Image : 4147200
Colorspace : sRGB
Transfer Function : Rec. 709
YCbCr/HSV Encoding: ITU-R 601
Quantization : Default (maps to Limited Range)
Flags :
Crop Capability Video Capture:
Bounds : Left 0, Top 0, Width 1920, Height 1080
Default : Left 0, Top 0, Width 1920, Height 1080
Pixel Aspect: 1/1
Selection Video Capture: crop_default, Left 0, Top 0, Width 1920, Height 1080, Flags:
Selection Video Capture: crop_bounds, Left 0, Top 0, Width 1920, Height 1080, Flags:
Streaming Parameters Video Capture:
Capabilities : timeperframe
Frames per second: 20.000 (20/1)
Read buffers : 0
brightness 0x00980900 (int) : min=0 max=255 step=1 default=128 value=128
contrast 0x00980901 (int) : min=0 max=255 step=1 default=128 value=128
saturation 0x00980902 (int) : min=0 max=255 step=1 default=128 value=128
white_balance_temperature_auto 0x0098090c (bool) : default=1 value=1
gain 0x00980913 (int) : min=0 max=255 step=1 default=0 value=255
power_line_frequency 0x00980918 (menu) : min=0 max=2 default=2 value=2
0: Disabled
1: 50 Hz
2: 60 Hz
white_balance_temperature 0x0098091a (int) : min=2000 max=7500 step=1 default=4000 value=6500 flags=inactive
sharpness 0x0098091b (int) : min=0 max=255 step=1 default=128 value=128
backlight_compensation 0x0098091c (int) : min=0 max=1 step=1 default=0 value=0
exposure_auto 0x009a0901 (menu) : min=0 max=3 default=3 value=3
1: Manual Mode
3: Aperture Priority Mode
exposure_absolute 0x009a0902 (int) : min=3 max=2047 step=1 default=250 value=333 flags=inactive
exposure_auto_priority 0x009a0903 (bool) : default=0 value=0
pan_absolute 0x009a0908 (int) : min=-36000 max=36000 step=3600 default=0 value=0
tilt_absolute 0x009a0909 (int) : min=-36000 max=36000 step=3600 default=0 value=0
focus_absolute 0x009a090a (int) : min=0 max=255 step=1 default=0 value=0
focus_auto 0x009a090c (bool) : default=1 value=0
zoom_absolute 0x009a090d (int) : min=100 max=400 step=1 default=100 value=100
v4l2-ctl -d /dev/video9 --all
Driver Info:
Driver name : uvcvideo
Card type : Logitech StreamCam
Bus info : usb-3610000.xhci-1
Driver version : 5.10.104
Capabilities : 0x84a00001
Video Capture
Metadata Capture
Streaming
Extended Pix Format
Device Capabilities
Device Caps : 0x04a00000
Metadata Capture
Streaming
Extended Pix Format
Media Driver Info:
Driver name : uvcvideo
Model : Logitech StreamCam
Serial : 45231985
Bus info : usb-3610000.xhci-1
Media version : 5.10.104
Hardware revision: 0x00000317 (791)
Driver version : 5.10.104
Interface Info:
ID : 0x03000005
Type : V4L Video
Entity Info:
ID : 0x00000004 (4)
Name : Logitech StreamCam
Function : V4L2 I/O
Priority: 2
Format Metadata Capture:
Sample Format : 'UVCH' (UVC Payload Header Metadata)
Buffer Size : 1024
So how could I choose which to capture from video8 and video9 ?
The problem is same with the post which has not been solved.