MP3 Compatibility

MP3 Compatibility (Fix Chant Audio Files)

MP3 compatibility — check this before adding new packs. Playback goes through Windows' legacy MCI (mciSendStringW, opened as type mpegvideo), not a modern MP3 decoder, and it is far less tolerant of unusual file packaging than something like VLC or a phone. A file that plays fine everywhere else can still make MCI refuse to open it, and the app has no visible error for this: the track is silently skipped forever (retried every ~0.5s, always failing) while the Chants tab freezes on whatever status was last shown. The only trace is in runtime/server16.log, as a repeating Chants monitor error: MCI command failed (277): open "... line.

The confirmed trigger, across two independently failing files: the leading ID3v2 tag itself — not its size. One failing file had an oversized tag (~76% of file size, a large embedded cover image); a second failing file had a perfectly ordinary tag (~0.8% of file size, no obvious defect in the audio frames either — verified frame-by-frame end to end with no desync). Both were fixed the same way, and isolated testing on the second file confirmed it precisely: stripping only the leading ID3v2 tag fixed it, while stripping only the trailing ID3v1 tag (and leaving ID3v2 in place) did not. Tag size is not a reliable predictor — a small, unremarkable-looking ID3v2 tag can still make MCI refuse the file, presumably over some specific frame/encoding inside it that this legacy driver's parser doesn't like. If a newly added chant never seems to play and the log shows the error above:

1. Click Fix Chant Audio Files on the Chants tab (next to Edit Chants Settings). It walks every .mp3 under FSW/Chants, strips any leading ID3v2 tag in place, and keeps a <name>.original.mp3 backup of anything it touches — safe to run any time, including after adding a new pack, and safe to run repeatedly (already-clean files are left alone).
2. If you'd rather fix a single file by hand instead: strip its ID3v2 tag entirely (embedded artwork included) with any tag editor (Mp3tag) or ffmpeg -i in.mp3 -map_metadata -1 -id3v2_version 0 -c copy out.mp3, then replace the file and try again.

As a rule of thumb for any new pack: run Fix Chant Audio Files after adding it, rather than only reaching for it once a specific team's chant is confirmed silent — a normal-looking tag is not proof the file will open.