Carnac is a feature that analyzes new files as they are being Imported, and tries to fill empty database fields by using available information about the file (such as filename, length, file type, and other details). It does not alter existing tags. It is most useful for videos since video files seldom have embedded tags. Carnac was introduced with Media Center 17.0.10, and has been refined as development has continued.
When Carnac Runs
Carnac is an extension of tag reading and is part of Media Center's Auto-Import system. Carnac runs automatically when new files are imported into Media Center via:
- Background Auto-Importing
- Tools > Import > Import a single folder
- Tools > Import > Run Auto-Import Now
- Tools > Library Tools > Update Library (from Tags)
- Tools > Library Tools > Fill Properties from Filename in Automatic mode.
When reading tags from a file on a fresh import, or when doing Update Library (from tags), Carnac will only fill previously empty fields. It makes no changes at all to fields that are already present, or which come from an embedded file tag, or sidecar XML file. It only fills fields that are empty when the rest of the Import process completes.
You can also run Carnac manually by using Tools > Library Tools > Fill Properties From Filename and selecting 'Automatic' as the method. In this mode, Carnac will overwrite existing fields (instead of only empty fields). A full preview of changes is available in the tool.
Types of Files That Carnac Can Handle
Carnac will parse audio files with filenames like:
- [Artist] - [Album] - [Track #] - [Name]
- [Track #] - [Name]
And also try to extract additional details when available in the full filename structure.
A video file, that is less than two hours in duration long, with a filename like Seinfeld S02E05 The Apartment.mkv should fill:
- Series: Seinfeld
- Season: 2
- Episode: 5
- Name: The Apartment
It will recognize a variety of similar TV Series filename schemes that are commonly encountered.
A video that's 2 hours long will be tagged as a Movie, and the filename will be parsed differently. It will try to extract the year, and recognize the name of the movie if possible.
Carnac also tries to recognize videos that are likely to be Home Movies. For example, any video imported using the MiniDV codec, will be assumed to be a home movie, and will be tagged as [Media Sub Type]: Home Video.
The most important thing to understand when trying to troubleshoot failures in Carnac is that it only applies to:
- New files that have been imported into MC for the first time.
- The files must have been imported via Media Center's Auto-Import system (including using the choices under Tools > Import and the background import system).
If you import files by any of the other mechanisms such as the Shell Extensions or drag-and-drop, then Carnac is not applied. Also, if a file has previously been imported into MC, and then removed, and later re-imported, Carnac is not run on the file (the previous Library record is restored instead). Otherwise, Carnac tries to be certain before filling a tag, and does not overwrite existing fields. Be sure that the field isn't getting data via some other source (such as an embedded tag, or an existing JRSidecar file on disk).
If you encounter a common filename that doesn't get tagged correctly, please report it on Interact. Please include a full filename (including path), codec, duration, and other information about the file.