This is the sample code for Leopard USB3.0 camera linux camera tool. It is a simple interface for capturing, viewing, controlling video from v4l2 devices, with a special emphasis for the linux uvc driver.
- Leopard USB3.0 Camera Linux Camera Tool
Make sure the libraries have installed. Run configure.sh for completing installing all the required dependencies
chmod +X configure.sh
./configure.shMake sure you have GTK 3 and OpenCV (3 at least) installed. The way you do to install this package varies by operational system.
Gtk3 and Gtk2 don't live together peaceful. If you try to run camera tool and got this error message:
Gtk-ERROR **: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same proc
It is mostly you have OpenCV build with GTk2 support. The only way to fix it is rebuild OpenCV without GTk2:
opencv_dir/release$cmake [other options] -D WITH_GTK_2_X=OFF ..
in order to disable Gtk2 from OpenCV.
#rebuild opencv, this might take a while
rm -rf build/
mkdir build && cd build/
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D BUILD_NEW_PYTHON_EXAMPLES=ON -D BUILD_EXAMPLES=ON -D WITH_QT=ON -D WITH_OPENGL=ON -D WITH_GTK=ON -D WITH_GTK3=ON -D WITH_GTK_2_X=OFF ..
make -j6 #do a $lscpu to see how many cores for CPU
sudo make install -j6
#link opencv
sudo sh -c 'echo "/usr/local/lib" >> /etc/ld.so.conf.d/opencv.conf'
sudo ldconfig- Makefile
make- CMake
mkdir build
cd build
cmake ../
make
# Add to your project
add_subdirectory(linux_camera_tool)
include_directories(
linux_camera_tool/src/
)
...
target_link_libraries(<Your Target>
leopard_tools
)sudo cp ./leopard_cam /usr/binsudo rm -f /usr/bin/leopard_cam $ linux_camera_tool .
├── Makefile
├── configure.sh
├── CMakeLists.txt
│
├── README.md
├── CHANGELOG.md
├── LICENSE.md
├── AUTHOR.md
│
├── config.json
├── BatchCmd.txt
|
├── includes
│ ├── shortcuts.h # common header
│ ├── cam_property.h
│ ├── extend_cam_ctrl.h
│ ├── core_io.h
| ├── json_parser.h
│ ├── batch_cmd_parser.h
│ ├── ui_control.h
│ ├── uvc_extension_unit_ctrl.h
│ └── v4l2_devices.h
│
├── src
│ ├── cam_property.cpp # gain, exposure, ptz ctrl
│ ├── extend_cam_ctrl.cpp # camera stream. capture ctrl
| ├── core_io.cpp # string manipulation for parser
| ├── json_parser.cpp # json parser
| ├── batch_cmd_parser.cpp # BatchCmd.txt parser
| ├── ui_control.cpp # control GUI
│ ├── uvc_extension_unit_ctrl.cpp # all uvc extension unit ctrl
│ └── v4l2_device.cpp # udev ctrl
│
└── test
└── main.c
leopard_cam
Auto white balance, gamma correction and auto brightness and contrast are done by mainly using opencv, since histogram matrix calculations are involved, enabling these features will slow down the streaming a lot. Auto exposure is usually implemented on sensor/isp, which when enabled, won't further slow down the streaming, need to check with camera driver for auto exposure support.
Since Linux V4L2 API doesn't provide a easier way to tell you what exact exposure time in ms like what Windows does, here is the explanation for helping you figuring out your camera's current exposure time in ms:
Exposure time = exposure_time_line_number / (frame_rate * total_line_number)
, where
- exposure_time_line_number is the value that display is linux camera tool exposure control
- you can get frame_rate from log Get Current Frame Rate=, don't refer to Current Fps that displays in cam, that's the frame rate your PC can process, not the physically USB received frame rate from camera.
- total_line_number is usually around the height of the camera's current resolution, usually slightly larger than that since VD needs blanking. To get the exact total_line_number, you might want to read VTS register value for your sensor, which might be a hassle for you so I will only tell you this roughly calculation method...
- Noticing for exposure time change in Linux Camera Tool Control GUI, the exposure time range will usually be over the camera's resolution height. If you have the exposure value set to be over camera's resolution height, it might affect your frame rate, since camera exposure time line number is greater than the total line number, that will slow down your camera's frame rate. But this varies from different sensors. Some sensors don't allow that happen, so the exposure time will stick the same when it is over total line number.
Original streaming for IMX477:
image is dark and blue
Modified streaming for IMX477:
enabled software AWB, gamma correction read & write register from IMX477
enable software auto brightness and contrast
Modified streaming for OS05A20 full resolution
change bayer pattern to GRBG enable software AWB, gamma correction increase exposure, gain
Modified OS05A20 resolution to an available one
binning mode capture raw and bmp, save them in the camera tool directory
Original streaming for AR1335 ICP3 YUV cam:
Default ae enabled -> change exposure&gain takes no effects
Disable ae:
Being able to change exposure & gain taking effective
- Use ESC on both of GUI.
- Use EXIT button on the control panel to exit the whole program
- User Ctrl + C to exit the control panel after exit from camera streaming GUI
- Unexpected quit results in defunct process, use ps to see if the leopard_cam still alive, if it is, use killall -9 leopard_cam to kill the zombie process
If you forget to exit both windows and tried to run the camera tool again, it will give you the error of
VIDIOC_DQBUF: Invalid argumentPlease check your available processes and kill leopard_cam, then restart the camera tool application
ps
killall -9 leopard_cam- 4.18.0-17-generic #18~18.04.1-Ubuntu SMP
- 4.15.0-32-generic #35~16.04.1-Ubuntu
- 4.15.0-20-generic #21~Ubuntu 18.04.1 LTS
When changing exposure and gain under linux, camera tool will experience split screen issue at the moment change is happened. This issue happens for the USB3 camera that use manual DMA in the FX3 driver. For the camera that utilizes auto DMA, the image will be ok when exposure and gain change happens.
For updating driver from manual DMA to auto DMA, you need to ensure:
- PTS embedded information is not needed in each frame
- The camera board has a Crosslink FPGA on the tester board that is able to add uvc header to quality for auto DMA
- FX3 driver also need to be updated.
When use triggering mode instead of master free running mode for USB3 SerDes camera, the very first frame received will be bad and should be tossed away. It is recommended to use an external function generator or a dedicated triggering signal for triggering the cameras for the purpose of syncing different SerDes cameras.
The included "shot 1 trigger" function is only a demonstration on generating one pulse and let camera output one frame after "shot 1 trigger" is clicked once. User should not fully rely on this software generated trigger but use a hardware trigger for sync the camera streaming.