Naming & folders · How we test and maintain this guide
Renaming a file does not set its title tag
A music player can display an embedded title, artist, album and track number instead of the filename you see in the folder. Changing a filename in TuneBundle does not write those tags. The workspace exports filenames and a CSV record; it is not an embedded-metadata editor. Keep that capability boundary clear before expecting a renamed file to look different in a player.
ID3 is associated with MP3 metadata, while other containers have their own tagging conventions. A field that works in one format or application may be displayed differently in another. Work on a copy and test the player that matters to you. Do not apply invented artist credits or ownership statements merely to fill an empty field.
A tag edit we actually performed
| Field in the tagged test file | Probed value |
|---|---|
| title | Controlled title |
| artist | TuneBundle test signals |
| album | Filing example |
| track | 2/3 |
| Size before / after | 2401219 / 2401323 bytes |
We used a self-generated MP3 signal, copied the audio stream into a new file and wrote four test tags. The complete-file SHA-256 changed, while decoding both files with the same FFmpeg settings produced the same PCM SHA-256. This gives a concrete example of metadata changing file identity without a decoded-audio change in that test.
The following command shows the method using a harmless example filename. Run it only on a copy you control, with FFmpeg installed, and choose a new output filename. The command does not instruct an overwrite of the input:
ffmpeg -i "source.mp3" -map 0:a:0 -c:a copy -id3v2_version 3 -metadata title="Controlled title" -metadata artist="TuneBundle test signals" -metadata album="Filing example" -metadata track="2/3" "tagged-copy.mp3"Stream copying avoids an additional audio encode in this example. Mapping only the first audio stream also means this is not a general recipe for retaining every attachment, artwork or extra stream in a complex file. Read the FFmpeg documentation before adapting the method to a different container or preservation requirement.
Use a written mapping for a real collection
- Keep the original export and its manifest untouched.
- Create a small working copy and write down the intended title, artist, album and track number for each file.
- Check those values against real credits and the destination's needs. A source song title does not establish the artist or licence.
- Apply the tags to one representative file first, then inspect the stored values with a tag reader or media probe.
- Open that actual file in the target player and confirm the display and order before applying the same method to the remaining copies.
The CSV produced by TuneBundle is a record of the prepared export. It is not automatically updated after an external tag editor changes a file. Retain the original CSV and keep a working map of the later paths and hashes. If you distribute a newly tagged set, produce records for that set rather than expecting an old source hash to match.
A batch operation deserves a preview. Watch for accidentally writing one title to every file, reversing track order, or treating a filename suffix as an official take number. Tagging tools differ, so this guide uses an explicit single-file example rather than claiming that a particular bulk editor was tested.
Inspect the file and the application
A player can keep a cached library entry after tags change. If its display disagrees with a fresh probe of the file, check the player's rescan or library-refresh behaviour before rewriting the tags repeatedly. Make sure the player is opening the edited copy rather than an older file at another path.
Listen to the beginning and end after editing and compare duration where relevant. A preserved decoded hash is a useful technical result for our controlled sample; it does not replace a check of your actual files, artwork and target application. Record the tool and method used so the next revision can be understood or reversed.