Edit decision list
|This article does not cite any references or sources. (March 2010)|
||This article may be too technical for most readers to understand. (March 2010)|
An edit decision list or EDL used in the post-production process of film editing and video editing. The list contains an ordered list of reel and timecode data representing where each video clip can be obtained in order to conform the final cut.
EDLs are created by offline editing systems, or can be paper documents constructed by hand such as shot logging. These days, linear video editing systems have been superseded by non linear editing (NLE) systems which can output EDLs electronically to allow autoconform on an online editing system – the recreation of an edited programme from the original sources (usually video tapes) and the editing decisions in the EDL.
They are also often used in the digital video editing world, so rather than referring to reels they can refer to sequences of images stored on disk.
Some formats, such as CMX3600, can represent simple editing decisions only. XML[specify], the Advanced Authoring Format (AAF), and AviSynth scripts are relatively advanced file formats that can contain sophisticated EDLs.
Linear editing systems cannot dissolve between clips on the same video tape. Hence, one of these clips will need to be dubbed onto a new video tape. EDLs designate these occurrences by marking such dissolves' source reels as B-roll of "b-reels". For example, the EDL will change the 8th character of the reel name to the letter B.
However, sometimes editors will (confusingly) use the letter B to designate time code breaks on a video tape. If there is broken time code on a video tape, there will be two (or more) instances of a particular time code on the video tape. When re-capturing, it can be ambiguous as to which timecode is the right one. The letter B may indicate that the right time code is from the second set of timecode on the video tape.
EDL incompatibilities and potential problems
EDL formats such as CMX, GVG, Sony, Final Cut Pro, and Avid are similar but can differ in small (but important) ways. Particular attention should be paid to reel naming convention. On the Avid, reel names can be up to 32 characters, but user should be aware that these EDL's don't adhere to online editing machine control specifications. These are used by systems that have modified the import/export code to handle file-based workflows as tape acquisition formats wane. On FCP, in CMX3600 format, only eight characters are allowed. Particular attention should be paid towards b-reels. If the EDL handles dissolves to the same reel, reel names should be limited to 7 characters since the 8th character may be replaced.
EDLs can use either drop-frame (DF) or non drop-frame timecode (NDF), running at 24fps (non drop-frame only), 25fps (non drop-frame only), and 30fps (drop-frame and non drop-frame).
Overall, EDLs are still commonly used as some systems do not support other more robust formats such as AAF and XML.
Systems known to support EDL to some extent
Almost any professional editing system and many others support some form of XML/EDL saving/processing.
Some that make the list:
- Avid Media Composer
- Adobe Premiere Pro
- The Foundry HIERO
- Blender supports EDL in versions 2.4x and versions from 2.66
- Final Cut Pro
- Fairlight Dream II and Xynergi systems
Systems supporting EDL playback, not just EDL cutting
Probably most of the above, plus any professional editing system, plus
- Avidemux project files.
- BSplayer 
- MPlayer (see also http://linuxgazette.net/178/brownss.html)
- MythTV cut list
- VLC media player with xspf files that specify start and end times, or with movie content editor
- Zoom Player Max
- Keykode (Film editing)
- Commercial skipping sometimes uses EDL's to track commercial blocks.