Hi,
So far converting all the tags to ID3v2.3 and then adding the artwork is working for me. I will briefly summarize my experience in few lines for future reference to other readers.
-Originally all my .mp3 files were tagged ID3v2.4 with .jpg artworks
-When setting my Firefly media directory pointing to my .mp3 folder I experienced the problem described at the beginning of the topic.
-I tried downgrading the tags to ID3v2.3, v2.2 and v1.1 with no success.
-The tagging problem was solved when I converted the tag format to “None” (using iTunes) and then back to v2.4; losing the artwork for all my .mp3 files.
-As soon as I tried to add any artwork to my .mp3 files tagged ID3v2.4 the problem reappeared.
The solution was:
With all the artwork removed from my ID3v2.4 tagged files, convert the tags to v2.3; then, add the artwork. Seems that the JPEG-ID3v2.4 combination causes some sort of indigestion to either mt-daapd and/or libao_0.8.6-1.
If you, as me, are using iTunes for importing your CD collection; this software creates ID3v2.2 tags by default in your files. Adding artwork to these files works fine for Firefly and iTunes but in my case not for the Archos AV400 Portable Media Player (and maybe others). So I have to stick to ID3v2.3 tags.
Thank guys for all your help! Especially Ron, you’re doing an amazing job.