Media Files and Annotation Files


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Every ELAN project consists of at least two files: one (or more) media file(s), and one annotation file.

One (or more) media file(s):

zero or more video file(s) (*.mpg, *.mp4 etc.)
and/or one (or more) audio file(s) (*.wav etc.)

The video file allows you to view the video and listen to the sound. If you want to view the waveform as well, you might need to create an additional *.wav file through a conversion program that converts the audio data from a video file into a *.wav format. As of version 6.1 for Windows and macOS and 6.4 for Linux, attempts are made to show the waveform directly from the audio track of the video (but a *.wav file can still be more accurate and perform better). In the case of multiple video files, the audio of the first selected video file is played (audible). The kind and number of supported video formats depend upon the media framework you are using. If your media framework supports a format, the same probably goes for ELAN.

The following media frameworks are known to work:

	Note
	Which frameworks are actually available depends on the ELAN variant and the operating system.

Windows (in order of preference, DirectShow/Microsoft Media Foundation being the best solution):
- JDS (Java Direct Show)
  - Java - Microsoft Media Foundation (.mp4, .m4a,. m4v (win 7 and higher), .wmv, .wma, .asf)
- JavaFX Media Framework (.mp4, .wav)
- VLC Player Library (Java wrapper for VLC Player 3.x)
- Java Sound (.wav)
MacOS (in order of preference):
- Java - AV Foundation Framework
- JavaFX Media Framework (.mp4, .wav)
- VLC Player Library (Java wrapper for VLC Player 3.x)
- Java Sound (.wav)
Linux (in order of preference):
- VLC Player Library (Java wrapper for VLC Player 3.x)
- JavaFX Media Framework (.mp4, .wav)
- Java Sound (.wav)

Note

There are several issues with the VLC based player. Depending on the platform options like zooming in or frame stepping might or might not work. Spherical or 360-degree .mp4 videos currently don't work on macOS. It may sometimes be necessary to resize the video area to enforce an update of the video image.
For *.mov files (i.e., Cinepak-Quicktime-Movies) it is important that these are self-contained files, i.e., the video information needs to be contained within the *.mov file itself. If this is not the case, ELAN will not be able to display the file.
Unlike other media files, the playback rate of Windows Media Audio (WMA) files cannot be altered.

One annotation file:

an annotation file created by ELAN ( *.eaf , “EUDICO Annotation Format”)
or an imported annotation file. See the the section called “Import from” section for the supported formats.

All information (e.g., the tier setup, the time alignment, the annotations) is saved to the annotation file only – never to the media file(s).

	Note
	Take care when editing a media file. Afterwards you probably will want to resynchronize its alignment with the corresponding annotations, as described in (the section called “Synchronizing video files”).

Although it's not compulsory it is a good practice to use a common name for media files and the annotation file. So, it is recommended to use e.g. a.eaf next to a.mp4 and a.wav.

Imported files also do not need to have the same name as their media files, and they can be located in different directories. All imported files can ultimately be saved as ELAN files ( *.eaf ).

All annotation files ( *.eaf ) can be exported as text, FLEx, Toolbox etc.