4.1. Basic Information: Media Files and Annotation Files

4.1. Basic Information: 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):
- 0 or more video file(s) (*.mpg, *.mov etc.)
- and/or one audio file (*.wav)

The video file allows you to view the video and listen to the sound. If you want to view the waveform as well, you need to create an additional *.wav file through a conversion program that converts the audio data from one *.mp(e)g file into a *.wav format. In the case of multiple video files, the audio of the first selected video file is played. 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 goes for ELAN.

The following media frameworks are known to work:

Windows (in order of preference, DirectX being the best solution):
- JDS (Java Direct Show)
  - Java - Microsoft Media Foundation (.mp4, .m4a,. m4v(win &only), .wmv, .wma, .asf)
- DirectX/DirectShow (Windows Media Player)
- QuickTime
- JMF (Java Media Framework)
MacOS (in order of preference):
- QuickTime using the Cocoa Framework (QTKit)
- QuickTime using QuickTime for Java
Linux: JMF

Note

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. The following formats can be imported:Shoebox/Toolbox files (with the extension *.txt)
- CHAT files (*.cha)
- Transcriber files (*.trs)

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 the annotations, as described in Section 4.2.3.

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 a.eaf next to a.mpg and a.wav.

Imported Shoebox files (*.txt) 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 alternatively be saved as ELAN files (*.eaf).

All annotation files (*.eaf) can be exported as text, Shoebox/Toolbox and CHAT files.