This video demonstrates how to find all matching values between two columns in LibreOffice Calc. Precisely, in this video, we fill in columns A and B with random integer values between the numbers 1 and 100 (inclusive). The formula to generate the random values was the following:
=RANDBETWEEN(1;100)
After we filled in columns A and B with random values, we used the following formula in each cell of column C to find all common values between the first two columns:
=IF(ISERROR(MATCH(B1;A:A;0));"";B1)
LibreOffice Cal commands used in this video
RANDBETWEEN(Bottom; Top) – Returns an integer random number in a specified range.
IF(Test; ThenValue; OtherwiseValue) – Specifies a logical test to be performed.
ISERROR(Value) – Tests for error conditions, including the #N/A error value, and returns TRUE or FALSE.
MATCH(SearchCriterion; LookupArray; Type) – Returns the relative position of an item in an array that matches a specified value. The function returns the position of the value found in the lookup_array as a number.
The above command exported the video frames into the selected folder and using eight digits zero-padding it named all the images in an increasing order starting from the number 00000001 (00000001.ppm).
Later on, we processed those frames and deleted some of the first ones (specifically, we deleted the first 61 frames, so the first available frame was named 00000062.ppm). When we tried to rebuild the video using the command below, we got the error that is listed after the command:
Please note that we also used -pix_fmt yuv420p as we were getting a video with black frames only, so we had to define the format of the pixels to use manually.
Recently, we were trying to apply blurriness to the frames of a video using a custom mask. Our needs would not be short of describing using geometric shapes, so we created the following image (blur.png) as a template for the blurring effect:
The above mask applies a blur effect to all black pixels and leaves all white pixels in the original image intact.
This command creates a new copy of the input file and places it into the folder named blur, so be sure to make the folder before using the above command (e.g., using the command mkdir blur).
Parameters and other information
-mask this flag assosiates the filename that is given with the mask of the command.
-blur defines the geometry that is used reduce image noise and reduce detail levels. To increase the blurriness you can increase the number in this variable 0x8.
+mask The ‘plus’ form of the operator +mask removes the mask from the input image.
The version of convert that we used for this example was the following:
The above command finds all frames in the current folder and executes the convert command described above. Since FFmpeg names the frames as PPM, we used that to filter our search. The blur folder is in the same folder as the original images. To avoid processing the pictures in that folder again, we defined the -maxdepth parameter in find that prevents it from navigating into child folders of the one we are working in.
In this video, we demonstrate to the user where they can find their JetBrains fallback license and the fallback versions of the products they had purchased in the past.
After finding the list, the user has a couple of options to proceed. They can either download the archives from the website or install the correct version using a package manager like snap.
To install using snap, the first thing to do is call the snap info command and get the list of available versions or the available channels as they are called in snap.
From there, the user needs to select any of the versions available up to the version number that their JetBrains profile mentions they can get. For this demo, we chose version 2020.3/stable (2020.3/stable: 2020.3.3 2021-03-16 (208) 425MB classic), which was the maximum version allowed for our license. The installation command of that specific version using snap is as follows:
We had to add the classic flag as instructed by the version we decided to install.
This revision of snap "phpstorm" was published using classic confinement and thus may perform arbitrary system changes outside of the security sandbox that snaps are usually confined to, which may put your system at risk.
