Running Krut on Windows

Video Recording

Sound Recording


Video/Audio formats

1. Running Krut on Windows

Here are some quick instructions on how to run the program on the newer versions of Windows. (You need to have Java installed, but there is a good chance that you already do. Otherwise, see below.)

To run the program, it is usually sufficient to just double click on "krut.bat" or "KRUT.jar" after you have extracted the zip-archive into a folder of your choice (you have to extract the archive somewhere).

If you double click "KRUT.jar" and then you only get a list of other programs to choose from (such as "Start krut using..."), you should choose the one that says "Java (something)".

If double clicking does not work at all, try right clicking and see if there are any "Open With"-alternatives. If there is an "Open With -> Java (something)" alternative, that should do it.

If there is no "Open With" alternative when you right click, try to hold down a Shift-button while you right click and see if there is an "Open With" alternative now.

If none of this works, there is probably some problem with your Java-installation. Go to a Java download site (at the time of writing and download and reinstall your Java. Then try again.

2. Video recording

Video can be recorded at a given frame rate (fps) and played back at another. If the recording fps is changed, the playback fps will be changed along with it, so the playback fps must be changed last.

The capture area on the screen is chosen like this:

- Press either one of the mouse pointer buttons (in the main window or in the Settings window)

- Move the mouse to the TOP LEFT corner of the capture area.

- Press and hold CTRL.

- Move the mouse to the BOTTOM RIGHT corner of the capture area.

- Release CTRL.

The capture area can also be set manually in the Settings window. The capture area can be checked by clicking the "Snap" button before recording.

For a description on how to disable graphics overlay, for example to enable video recording from most media players, see the readme-files and video files.

It is possible to have the capture area follow the mouse pointer position during recording. The movements of the capture area are determined by normal acceleration mechanics, which are fairly pleasing to the eye. When the mouse pointer gets close to the edge of the capture area, the capture area is re-centered around the mouse pointer. This method allows the entire screen to be shown in an instructional video with smaller dimensions.

Learning to move the capture area smoothly can take some practice. The best results come from simply moving the mouse pointer directly to the point which should be the new center of the capture area, and then holding the mouse pointer still for a couple of seconds, while the capture area moves.

To allow the best possible use of the screen during a video with a moving capture area, it is recommended that the Preview Window is used. On slower computer systems, the Preview Window can be a strain on the system resources, causing the movie quality, primarily audio, to suffer.

3. Sound Recording

For a general description on how to enable sound recording, please see the readme-files in each release.

The sound recording can currently only be made in the wav format. Encoding in other formats might be added. In the mean time, the recorded wav-file can be used for manual encoding into whatever format is wanted. If a suitable encoder for the mp3 format is released for in java, it is very likely that it will be added to Krut. At the time of writing, no such encoder has been found.

Sound synchronization works by comparing the recorded time of sound to the system clock. Since video synchronization uses the same principle, this will ensure that sound is synchronized to video, as long as sound synchronization is active. However, if the system clock and the clock of the device playing the sound run at different speeds, this may mean that both sound and video are recorded at the wrong speed.

If video recording and video playback are set to different frame rates, sound will stay synchronized to the video track instead of the system clock.

Sound synchronization is necessary to maintain sync between audio and video in longer movies, since random frames will inevitably be lost in the recording process.

The other settings for sound recording should hopefully be self explanatory.

4. Files

Files can be selected by either entering the file names directly in the Settings window or by using the browse buttons for each file. If the “overwrite save files” check box is checked, the written files will have the chosen file names, otherwise the program will find the first available file name by adding numbers.

The following files are produced by the program:

Audio files - wav files containing the recorded audio tracks.

Image files - jpg files containing the recorded snapshots.

Movie files - mov files containing the recorded movies.

In addition to these files, mov files of the names, etc. are produced, containing only video data. These temp files are located in the same directory as the movie files. If there is no audio recording, only the temp files will be produced.

After recording, the temp files and the audio files can be used to create new movie files using other software.

All the files mentioned so far will remain after the program is closed, and they will have to be deleted manually if they are unwanted.

There are also temporary storage files created in the home directory of the program. These files will remain after the program is closed, but they will contain no data.

5. Video/Audio formats

The video format used for recording is the quicktime mov format. This is because at the time of writing the program, the mov format seemed to be the most supported format in the Java Media Framework (JMF), which is used to encode the video file. As there has been little further development of the JMF, the incorporation of different video formats would require extensive rewrites of Krut. This may happen in the future, as inclusion of additional video formats is a high priority.

The mov video files used in Krut simply consist of series of jpg encoded images, so the files can be re-encoded into other video formats by many other video encoding programs, which are available on each individual platform.

The audio format used in mov files with sound, as well as the audio-only files, is wav. This means that high quality audio recordings can make up substantial parts of the total movie files. At the time of writing, no open, cross-platform, java based mp3 (or other) audio encoding program has been found. Because of this, it has been considered easier to stay with the wav-format, allowing users to re-encode the films to any desired format on their respective platforms. Inclusion of additional audio formats is a high priority

If there is better support for other media formats in Java in the future, there is a considerable chance that Krut will be updated to include them. At present, the most desired formats are mp3 (cross platform encoding required), and any completely free, open video format including audio, such as Ogg Vorbis.