The ALE format has not really kept up with changes in Media Composer that have been going on with the past several releases. While ALE still has limitations to be aware of when using custom columns and such as discussed here, the ALE header is the subject of this blog, and what you need to know when importing/exporting for different needs.
The ALE is basically a TAB delimited text file with three main sections:
Additional information on the columns and basic ALE formatting can be seen in this Avid whitepaper that unfortunately is good for Media Composer 7.0.2 and earlier and does not reflect any of the changes and new columns that have been added since December 2013.
The Header defines global properties of all events listed. Any event can override a global value if that column is listed and the value differs from the global value. Since that function exists, the global value does not offer much value and can prevent an ALE from being imported as seen in the image above. Media Composer now allows for different frame rates to exist in the bin, so even the FPS section of the header really holds no value since the rate is defined in each event. But the global header entry that really has no value is the “VIDEO_FORMAT”. Before 2K+ projects were introduced, this field would display NTSC, PAL, 1080/720. But when greater than HD projects were introduced, it now reads CUSTOM which really means nothing other than it is not NTSC, PAL, 1080, or 720.
Example of an HD ALE (click to enlarge):
Same clip exported from the project as UHD (click to enlarge):
Notice that the clip itself has Image Size and FPS defined and each clip could have a different value and that is well supported. But the VIDEO_FORMAT will prevent an ALE from importing into the bin if CUSTOM is listed and you are trying to import into an HD project, and vice versa. The user needs to open the ALE in a text editor and change that. There is no need to do so, since that simple edit lets it import. Why not at very least introduce an “ignore” option when this is encountered? Better yet, when importing into a 2K+ project type, just ignore the VIDEO_FORMAT value altogether. And then again, one can argue that the Global Header itself is no longer needed in later versions of Media Composer and that a basic TAB file is much easier to deal with.
- FIELD_DELIM: This can be automatically detected or prompted is MC were to support different types
- VIDEO_FORMAT: No longer needed and has been made pointless with CUSTOM
- AUDIO_FORMAT: Already ignored as clips take on Audio/Project Settings
- FPS: Each clip has a FPS value as part of the spec, and the user could be promoted if an issue arises during import
Without the header it means “Column” and “Data” can be removed as well as TAB files are defined as first line as header everything else is data. So the above would now look like (click to enlarge):
An ALE export would still need to exist to have backwards compatibility, but the whole process of getting metadata into Media Composer for recent versions can be made a lot easier without the user trying to figure out what to fix to make it work and needing an extra step in a text editor.
Then there is the need for a more robust format - TAB would be used for quick and easy interchange but an XML schema would allow for more metadata to be described that goes well beyond what a clip-based/TAB file can offer.