Create screencasts with menyoki

Recording!

After selecting the appropriate window, start recording by pressing Alt+Enter (Figure 3). The same key combination will stop the recording later. Menyoki records the video in RAM and writes it to your hard disk when you stop recording. This approach causes the main memory to quickly fill (depending on your memory size) and the system to freeze, making menyoki only suitable for short recordings.

Figure 3: Before recording starts, menyoki displays a countdown in the terminal, as well as in the upper right corner next to the area to be recorded.

In the default setting, the software records at 20 frames per second; however, for many tutorials, something as low as 15 could be fine. Although the results are more jerky, the finished animation also takes up less storage space. In addition, a lower frame rate gives you a longer recording time. Use the --fps parameter to define menyoki's recording frame rate. Unusually, this value follows the file format specification (Listing 3, line 1).

Listing 3

Menyoki Options

01 $ menyoki record gif --fps 15 save "film.gif"
02 $ menyoki record --root --size 320x200 --padding 100:0:0:50 gif save "film.gif"
03 $ menyoki -q record --duration 1 save "-" | convert - "film.miff"

With the --root parameter, menyoki can capture the entire desktop. If you use multiple monitors, use --monitor <NUM> instead, where NUM corresponds to the monitor number to be recorded. Another parameter, --focus, lets you immediately record the currently focused window. The --select parameter lets you choose the window to be recorded.

If you only want to capture a section of the desktop, move the green highlight rectangle to the appropriate position using Shift+Alt and the arrow keys. Alternatively, specify the size of the area directly. For example, line 2 of Listing 3 captures a 320x200 pixel area of the desktop (Figure 4). The --padding switch moves the recording area 100 pixels down and 50 pixels to the right from the upper left corner of the screen.

Figure 4: Menyoki will capture the section in the red frame with the settings shown in line 2 of Listing 3.

Menyoki also supports the --duration parameter, which lets you specify the recording time in seconds, avoiding the need to cancel recording manually. This parameter is especially useful if you use menyoki in a shell script. You can then pipe the generated animations to other programs (Listing 3, line 3).

The -q option tells menyoki to remain mute. The save "-" parameter sends the animation to standard output, which the | pipe then passes to convert. Finally, convert transforms the animation into the ImageMagick's MIFF format.

Cold Cuts

Some events happen too quickly to capture in a screenshot – for example, an important error message. To remedy this, first film the application at work and then break the animation into individual frames. Menyoki does this with the split action.

Line 1 of Listing 4 tells menyoki to store all frames from the video film.gif in JPEG format in ~/Videos/. The file names of the frames all start with frame_, to which menyoki appends the frame number. Consequently, in Listing 4, you will see the files frame_1.jpg, frame_2.jpg, frame_3.jpg, and so on. In addition to JPG, menyoki also supports BMP, ICO, PNG, PNM, TGA, TIFF, and FF (farbfeld) file formats.

Listing 4

Editing Movies

01 $ menyoki split --dir ~/Videos/ "film.gif" jpg
02 $ menyoki edit --ratio 1.5 "frame_3.jpg" save "frame_3_big.jpg"
03 ### Scale multiple images at the same time:
04 $ for file in *.jpg; do menyoki edit --ratio 1.5 "$file" save "$file"; done
05 ### Combine individual images to create a movie:
06 $ menyoki make --dir ~/Videos/ --fps 15 --format gif save film2.gif
07 ### Pass in image files instead of directory
08 $ menyoki make --fps 15 --format gif "frame_1.jpg" "frame_2.jpg" "frame_3.jpg" save film3.gif

You can now retrieve the rapidly disappearing error message from the individual images. If the font appears too small, menyoki can enlarge the selected image directly with the edit action (Listing 4, line 2). The --ratio parameter scales the image by a factor of 1.5, preserving the aspect ratio. The results are then stored in the frame_3_big.jpg file.

Menyoki also supports other types of image modifications (see Table 1). Currently, however, menyoki only edits a single image and not the complete image sequence. To quickly scale all frames by a factor of 1.5, use the command from line 4 of Listing 4.

Table 1

Image Processing Functions

Parameters

Meaning

--grayscale

Converts image to grayscale

--crop <T:R:B:L>

Crops the image by the specified top, right, bottom, and left pixel dimensions

--resize <W>x<H>

Resizes the image by width and height without preserving the aspect ratio

--ratio <RATIO>

Resizes the image proportionally preserving the aspect ratio

--rotate <ROTATE>

Rotates the image clockwise (possible values: 90, 180, 270)

--flip <FLIP>

Flips the image (possible values: horizontal, vertical)

--blur <SIGMA>

Blurs the image

--hue <HUE>

Changes the hue

--contrast <CONTRAST>

Changes the contrast

--brightness <BRIGHTNESS>

Changes the brightness

After editing all the frames, menyoki can reassemble them into an animation if so desired (Listing 4, line 6). The --dir parameter defines the directory with the frames, and --fps 15 specifies a playback speed of 15 frames per second. --format is followed by the desired output format. Instead of your default directory, you can alternatively transfer to individual image files (line 8). The analyze subcommand lets you output technical information for the selected image file (Figure 5).

Figure 5: Using analyze gives you masses of technical information about an image or animation.

Menyoki can also create screenshots. This works in the same way as for an animation, but the associated action is capture (Listing 5).

Listing 5

Making a Screenshot

$ menyoki capture jpg save "screenshot.jpg"

Conclusions

Menyoki is the perfect tool to quickly record a process as a GIF or APNG animation. You can use menyoki to deconstruct your videos into individual frames, edit the individual images if necessary, and reassemble the image sequence into an animation. As a command-line tool, menyoki can also be easily integrated into custom shell scripts. For more examples of how to use menyoki, as well as documentation, visit the project's GitHub page [3].

However, menyoki does not yet come close to the functionality of other screencast programs. In particular, menyoki does not allow you to scale or post-process all extracted images at once. In addition, because of its mode of operation, menyoki is also only practical for short recordings.

Infos

  1. menyoki: https://menyoki.cli.rs
  2. Download menyoki: https://github.com/orhun/menyoki/releases
  3. menyoki project page on GitHub: https://github.com/orhun/menyoki

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