Monthly Archives: March 2018

Compiling DJI Onboard-SDK: error: ‘fd_set’ does not name a type

 in C++ / GNU/Linux  tagged compile / DJI / fedora / GNU/Linux / matrice / Onboard-SDK by

While compiling the DJI Onboard SDK on a Fedora GNU/Linux we got the following error:

[ 41%] Building CXX object osdk-core/CMakeFiles/djiosdk-core.dir/platform/linux/src/linux_serial_device.cpp.o
In file included from Onboard-SDK/osdk-core/platform/linux/src/linux_serial_device.cpp:33:0:
Onboard-SDK/osdk-core/platform/linux/inc/linux_serial_device.hpp:97:3: error: ‘fd_set’ does not name a type; did you mean ‘tzset’?
 fd_set m_serial_fd_set;
 ^~~~~~
 tzset
In file included from /usr/include/sys/types.h:197:0,
 from /usr/include/stdlib.h:279,
 from /usr/include/c++/7/cstdlib:75,
 from /usr/include/c++/7/bits/stl_algo.h:59,
 from /usr/include/c++/7/algorithm:62,
 from Onboard-SDK/osdk-core/platform/linux/src/linux_serial_device.cpp:34:
Onboard-SDK/osdk-core/platform/linux/src/linux_serial_device.cpp: In member function ‘int DJI::OSDK::LinuxSerialDevice::_serialStart(const char*, int)’:
Onboard-SDK/osdk-core/platform/linux/src/linux_serial_device.cpp:330:14: error: ‘m_serial_fd_set’ was not declared in this scope
 FD_ZERO(&m_serial_fd_set);
 ^
Onboard-SDK/osdk-core/platform/linux/src/linux_serial_device.cpp:330:14: note: suggested alternative: ‘m_serial_fd’
Onboard-SDK/osdk-core/platform/linux/src/linux_serial_device.cpp:331:26: error: ‘m_serial_fd_set’ was not declared in this scope
 FD_SET(m_serial_fd, &m_serial_fd_set);
 ^
Onboard-SDK/osdk-core/platform/linux/src/linux_serial_device.cpp:331:26: note: suggested alternative: ‘m_serial_fd’
make[2]: *** [osdk-core/CMakeFiles/djiosdk-core.dir/build.make:735: osdk-core/CMakeFiles/djiosdk-core.dir/platform/linux/src/linux_serial_device.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:86: osdk-core/CMakeFiles/djiosdk-core.dir/all] Error 2
make: *** [Makefile:130: all] Error 2

To resolve this, we added to the file Onboard-SDK/osdk-core/platform/linux/inc/linux_serial_device.hpp the following include directive right after line 37 (which contained #define LINUXSERIALDEVICE_H):


#include <sys/select.h>

Then, we issued make again which terminated successfully.

Source: https://github.com/dji-sdk/Onboard-SDK

Compilation Commands:


git clone https://github.com/dji-sdk/Onboard-SDK;

cd Onboard-SDK;

mkdir build;

cd build;

cmake ..;

#Modify the file Onboard-SDK/osdk-core/platform/linux/inc/linux_serial_device.hpp and add #include <sys/select.h> at the top

make all;

# Something

# Make profit

Lubuntu: “Do Nothing” when I close the laptop’s lid 4

 in GNU/Linux  tagged HandleLidSwitch / ignore / laptop / lid / logind.conf / lubuntu / screen / ubuntu by

A few days ago we setup a server on a laptop with lubuntu. We wanted to make sure that once the screen lid is off, the PC would not shut down (or hibernate or sleep) and it would continue to accept requests.

We tried to configure the PC through the system settings that are available with the GUI but we could not get it to work right. Anyhow, what we did in the end and worked was the following:

In the file /etc/systemd/logind.conf we set the variable HandleLidSwitch to ignore. So after the change, the following line was in logind.conf:

HandleLidSwitch=ignore

If the above line is commented out (i.e. starts with the character #, be sure to uncomment it by removing the # character).
After that, we had to restart the systemd-logind service as follows:


service systemd-logind restart;

Finally, to test we closed the lid and the server was operating as expected.

Note

If you have a power manager such as xfce4-power-manager-settings, it is a good practice to make sure it is configure properly first before doing the change above. (e.g. Set Lock screen or Switch off display in When laptop lid is closed option).

If you start xfce4-power-manager after you do the change above, you might have to restart the service again as the solution seems to stop.

Change date in GoPro video files 1

 in Bash / GNU/Linux  tagged date / EXIF / exiftool / GoPro / metadata by

Recently, we made some time-lapses with our GoPro camera which was not used for some time and discharged. Due to that, the date and time configuration of the camera was wrong and the resulting video files had wrong metadata information in their EXIF.

To update the dates in the produced video files we used the exiftool that is shipped in the perl-Image-ExifTool package. We use Fedora, so we used dnf to install the application with all needed dependencies as follows:


sudo dnf install -y perl-Image-ExifTool;

After installing exiftool, we used the following commands to change the dates and times of the video named GOPR6426 (and its preview / thumbnail video):


$ mydate='2018:02:23 15:20:00';
$ exiftool "-AllDates=$mydate" "-TrackCreateDate=$mydate" "-TrackModifyDate=$mydate" "-MediaCreateDate=$mydate" "-MediaModifyDate=$mydate" -overwrite_original GOPR4626.*;

Notes:

  • You need extra disk space to update the file as it creates a copy of it even if you overwrite the original
  • We used the wildcard character * in our command to make sure we update not only the main video but also the preview / thumbnail videos that GoPro produces.
  • If you skip -overwrite_original, then a new file will be created
  • We had to update several date fields in order to be sure that we covered all of them that were visible in the EXIF data of the media

Link to a newer post that handles folders of pictures and video using the time difference between the real date and the camera date.