Tuesday 29 September 2015

ubantu and point grey camera

We have to install flycapture drivers no matter we use win7 or ubantu. On win7, we only need to download the flycapture from the official website and it works out of the box. However, on ubantu we have to do several things.

The instructions I follow are basically taken from this. Note that in the README that came with FlyCapture ARM version, we have to copy all libraries to system folders. When it says do you want to restart udev daemon, type yes.

An error occurs

/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/libflycapture.so when searching for -lflycapture

It is not solved even after I restart the computer. I suspect that ARM version only works on embedded boards, not on desktop computers. So I follow the instructions here and it works.

In the code we have to include the header file by #include "FlyCapture2.h", but where is it? It turns out that we have to include /usr/include/flycapture in our cmake file.

Moreover, there is also a ROS package provided here. After installing it by sudo apt-get install ros-indigo-pointgrey-camera-driver, we only need to use roslaunch pointgrey_camera_driver camera.launch to use the camera.

Later I encounter another camera issue, as I could not get image from CM3-U3-31S4C-CS in Ubuntu 14.04.4 with ROS indigo and flycapture 2.9.3.43. No camera is detected in flycapture or rosrun pointgrey_camera_driver list_cameras. On the other hand, CM3-U3-31S4C-CS can be detected in Ubuntu 12.04 with ROS hydro for both flycapture and list_cameras command. However, there is no data output from the rostopics published by the camera, so I still could not get any image. Moreover, the camera works on my windows desktop with flycapture 2.8.3.1. 

Searching around, this post seems to be related, but I did not follow it. I uninstalled the flycapture and re-installed it. Previously, I did not see the prompt to enter user name, and this time I saw it. After installation was finished, the camera could work. 

Sunday 6 September 2015

Premier CS4 视频输出

编辑视频的时候经常遇到输出视频不流畅的情况。貌似是因为输出的帧率太高,文件太大导致的。尝试不同输出格式之后,发现H.264输出720p,帧率23的时候视频的流畅度比较高。