There are only a few ways to get metadata into Media Composer - either it comes with the media (essence) and available via AMA or in the MXF wrapper, via AAF, or an ALE file. ALE has been the go-to format since the original Avid/1 as it was the interchange between Media Composer and MediaMatch, the film matchback program. From there it became a pseudo-standard in many workflows and for the most part, the format has not changed since that time. Avid has a whitepaper that describes the basic formatting of the different bin columns and how they behave (read only, read/write). That whitepaper can be found here. Unfortunately it has not been updated with some important changes in 7.0.3 and all the new columns and metadata with new functionality added since that time for greater than HD project types. In the meantime, here are some things to be aware of that can cause problems when creating custom bin columns and working with ALE files to merge additional information into existing master clips. For Avid’s standard column, observing uppercase, lowercase, and spaces in an ALE is crucial to a successful merge. Custom columns have a different behavior.
When creating new columns, one needs to be aware as to how they are names. As you wills see through the different iterations of ALE merge and importing of an ALE, how a column is named will not support a merge operation, or when importing a new ALE file, keep metadata in the same columns. As seen in the screenshot, column names have been named with a variety of uppercase, lowercase, and spaces. The columns were created directly in the bin and the ALE exported from the bin. So far so good as they match. The one thing to note here is that creating columns with names greater than 14 characters will get truncated right off the bat.
(click images to see them actual size)
Then, a common practice might be updating existing values in a column from an external database or a quick way to edit bin metadata with a search and replace function. For this example, the values in the custom columns have been changed from 5 to 15.
Once merged, you will notice that only some of the columns have had their metadata updated:
Any column that had an uppercase for the any of the words in the column header did not get merged. Another workflow is rather than merging the clips, a production wants to import an ALE and make new master clip, but have the metadata be part of the same existing columns with the same name. In this example, the clips were given a different Tape Name to make them unique, and the metadata was changed from 15 to 25 to track what gets imported:
Very similar results that we saw with Merge. What happens is that the columns that did not get the metadata imported have actually become new column and can be seen in the column selection window:
Even column headings that are single word, but with a combination of uppercase/lowercase have the same issue:
Another thing to be aware of is if an ALE file has a column header that is longer than 16 characters it will also get truncated and get a “dot” character next to it in the bin. This is a different length limitation than when creating the column directly in the bin. Also, when exporting, that “dot” character gets reflected in the ALE:
Once an ALE has been imported and it creates its new columns, all new imports and merges from this point forward will work as expected. So to be safe, when making columns in the bin:
- Do not use UpperCase letters anywhere in the column name
- Avoid spaces, but they will work only lowercase characters are used. Use of an underscore works fine as a separator.
- Do not use column headers with more than 14 characters
- Not shown here, but experienced; long metadata fields in the body of the ALE will not even let the ALE import. The exact number hasn’t been tested, but my guess is around 128 characters.