Python 为什么'；V4L2 API是否显示正确的像素格式/宽度/高度参数？
我正在尝试根据V4L2 API设置V4L2摄像头的参数。Python 为什么'；V4L2 API是否显示正确的像素格式/宽度/高度参数？,python,linux-kernel,ubuntu-16.04,v4l2,pixelformat,Python,Linux Kernel,Ubuntu 16.04,V4l2,Pixelformat,我正在尝试根据V4L2 API设置V4L2摄像头的参数。 但是，API似乎没有显示操作系统设置的正确参数 您能否建议如何调试此问题，以确定相机无法显示正确的参数是否是一个问题 用我的密码 带着相机 还是使用API 问题演示： $ v4l2-ctl -d2 --set-fmt-video=width=424,height=240,pixelformat=1 $ v4l2-ctl -d2 --get-fmt-video | egrep 'Pixel Format|Width/Height'
但是，API似乎没有显示操作系统设置的正确参数 您能否建议如何调试此问题，以确定相机无法显示正确的参数是否是一个问题
- 用我的密码
- 带着相机
- 还是使用API
问题演示：
$ v4l2-ctl -d2 --set-fmt-video=width=424,height=240,pixelformat=1
$ v4l2-ctl -d2 --get-fmt-video | egrep 'Pixel Format|Width/Height'
Width/Height : 424/240
Pixel Format : 'UYVY'
$ python incorrect_pix_format.SO.py
>> device capabilities
Driver: uvcvideo
Camera: Intel(R) RealSense(TM) 410
video capture device? True
Supports read() call? False
Supports streaming? True
>> format parameters
pix_format.width: 0
pix_format.height: 0
pix_format.pixelformat: 0
>> Stop streaming
$ v4l2-ctl --list-formats-ext -d 2
ioctl: VIDIOC_ENUM_FMT
Index : 0
Type : Video Capture
Pixel Format: ''
Name : 00000032-0000-0010-8000-00aa003
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Index : 1
Type : Video Capture
Pixel Format: 'UYVY'
Name : UYVY 4:2:2
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Index : 2
Type : Video Capture
Pixel Format: 'Y8I '
Name : Greyscale 8 L/R (Y8I)
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Index : 3
Type : Video Capture
Pixel Format: 'Y12I'
Name : Greyscale 12 L/R (Y12I)
Size: Discrete 960x540
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.067s (15.000 fps)
$ cat incorrect_pix_format.SO.py
#!/usr/bin/env python3
from __future__ import print_function
import fcntl
import v4l2
def get_capability(vd):
cp = v4l2.v4l2_capability()
fcntl.ioctl(vd, v4l2.VIDIOC_QUERYCAP, cp)
return cp
def show_capability(cp):
print("Driver:", cp.driver)
print("Camera:", cp.card)
print("video capture device?\t", bool(cp.capabilities & v4l2.V4L2_CAP_VIDEO_CAPTURE))
print("Supports read() call?\t", bool(cp.capabilities & v4l2.V4L2_CAP_READWRITE))
print("Supports streaming?\t", bool(cp.capabilities & v4l2.V4L2_CAP_STREAMING))
def show_format(vd):
fmt = v4l2.v4l2_format()
pix_format = v4l2.v4l2_pix_format()
print("pix_format.width:", pix_format.width)
print("pix_format.height:", pix_format.height)
print("pix_format.pixelformat:", pix_format.pixelformat)
if __name__ == "__main__":
vd = open('/dev/video2', 'rb+', buffering=0)
print(">> device capabilities")
cp = get_capability(vd)
show_capability(cp)
print(">> format parameters")
show_format(vd)
print(">> Stop streaming")
vd.close()
OS: Ubuntu 16.04
V4L2 calls based on https://www.linuxtv.org/downloads/legacy/video4linux/API/V4L2_API/spec-single/v4l2.html
$ v4l2-ctl -d2 --set-fmt-video=width=424,height=240,pixelformat=1
$ v4l2-ctl -d2 --get-fmt-video | egrep 'Pixel Format|Width/Height'
Width/Height : 424/240
Pixel Format : 'UYVY'
$ python incorrect_pix_format.SO.py
>> device capabilities
Driver: uvcvideo
Camera: Intel(R) RealSense(TM) 410
video capture device? True
Supports read() call? False
Supports streaming? True
>> format parameters
pix_format.width: 0
pix_format.height: 0
pix_format.pixelformat: 0
>> Stop streaming
$ v4l2-ctl --list-formats-ext -d 2
ioctl: VIDIOC_ENUM_FMT
Index : 0
Type : Video Capture
Pixel Format: ''
Name : 00000032-0000-0010-8000-00aa003
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Index : 1
Type : Video Capture
Pixel Format: 'UYVY'
Name : UYVY 4:2:2
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Index : 2
Type : Video Capture
Pixel Format: 'Y8I '
Name : Greyscale 8 L/R (Y8I)
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Index : 3
Type : Video Capture
Pixel Format: 'Y12I'
Name : Greyscale 12 L/R (Y12I)
Size: Discrete 960x540
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.067s (15.000 fps)
$ cat incorrect_pix_format.SO.py
#!/usr/bin/env python3
from __future__ import print_function
import fcntl
import v4l2
def get_capability(vd):
cp = v4l2.v4l2_capability()
fcntl.ioctl(vd, v4l2.VIDIOC_QUERYCAP, cp)
return cp
def show_capability(cp):
print("Driver:", cp.driver)
print("Camera:", cp.card)
print("video capture device?\t", bool(cp.capabilities & v4l2.V4L2_CAP_VIDEO_CAPTURE))
print("Supports read() call?\t", bool(cp.capabilities & v4l2.V4L2_CAP_READWRITE))
print("Supports streaming?\t", bool(cp.capabilities & v4l2.V4L2_CAP_STREAMING))
def show_format(vd):
fmt = v4l2.v4l2_format()
pix_format = v4l2.v4l2_pix_format()
print("pix_format.width:", pix_format.width)
print("pix_format.height:", pix_format.height)
print("pix_format.pixelformat:", pix_format.pixelformat)
if __name__ == "__main__":
vd = open('/dev/video2', 'rb+', buffering=0)
print(">> device capabilities")
cp = get_capability(vd)
show_capability(cp)
print(">> format parameters")
show_format(vd)
print(">> Stop streaming")
vd.close()
OS: Ubuntu 16.04
V4L2 calls based on https://www.linuxtv.org/downloads/legacy/video4linux/API/V4L2_API/spec-single/v4l2.html
$ v4l2-ctl -d2 --set-fmt-video=width=424,height=240,pixelformat=1
$ v4l2-ctl -d2 --get-fmt-video | egrep 'Pixel Format|Width/Height'
Width/Height : 424/240
Pixel Format : 'UYVY'
$ python incorrect_pix_format.SO.py
>> device capabilities
Driver: uvcvideo
Camera: Intel(R) RealSense(TM) 410
video capture device? True
Supports read() call? False
Supports streaming? True
>> format parameters
pix_format.width: 0
pix_format.height: 0
pix_format.pixelformat: 0
>> Stop streaming
$ v4l2-ctl --list-formats-ext -d 2
ioctl: VIDIOC_ENUM_FMT
Index : 0
Type : Video Capture
Pixel Format: ''
Name : 00000032-0000-0010-8000-00aa003
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Index : 1
Type : Video Capture
Pixel Format: 'UYVY'
Name : UYVY 4:2:2
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Index : 2
Type : Video Capture
Pixel Format: 'Y8I '
Name : Greyscale 8 L/R (Y8I)
Size: Discrete 424x240
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 480x270
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 848x480
Interval: Discrete 0.011s (90.000 fps)
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.167s (6.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Index : 3
Type : Video Capture
Pixel Format: 'Y12I'
Name : Greyscale 12 L/R (Y12I)
Size: Discrete 960x540
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.067s (15.000 fps)
$ cat incorrect_pix_format.SO.py
#!/usr/bin/env python3
from __future__ import print_function
import fcntl
import v4l2
def get_capability(vd):
cp = v4l2.v4l2_capability()
fcntl.ioctl(vd, v4l2.VIDIOC_QUERYCAP, cp)
return cp
def show_capability(cp):
print("Driver:", cp.driver)
print("Camera:", cp.card)
print("video capture device?\t", bool(cp.capabilities & v4l2.V4L2_CAP_VIDEO_CAPTURE))
print("Supports read() call?\t", bool(cp.capabilities & v4l2.V4L2_CAP_READWRITE))
print("Supports streaming?\t", bool(cp.capabilities & v4l2.V4L2_CAP_STREAMING))
def show_format(vd):
fmt = v4l2.v4l2_format()
pix_format = v4l2.v4l2_pix_format()
print("pix_format.width:", pix_format.width)
print("pix_format.height:", pix_format.height)
print("pix_format.pixelformat:", pix_format.pixelformat)
if __name__ == "__main__":
vd = open('/dev/video2', 'rb+', buffering=0)
print(">> device capabilities")
cp = get_capability(vd)
show_capability(cp)
print(">> format parameters")
show_format(vd)
print(">> Stop streaming")
vd.close()
OS: Ubuntu 16.04
V4L2 calls based on https://www.linuxtv.org/downloads/legacy/video4linux/API/V4L2_API/spec-single/v4l2.html
def show_format(vd):
fmt = v4l2.v4l2_format()
fmt.type = v4l2.V4L2_BUF_TYPE_VIDEO_CAPTURE
fcntl.ioctl(vd, v4l2.VIDIOC_G_FMT, fmt)
print("width:", fmt.fmt.pix.width)
print("height", fmt.fmt.pix.height)
print("pixelformat", fmt.fmt.pix.pixelformat)