(Download the script here: reflac.sh)
Problem
When using oggenc to convert a FLAC file to OGG Vorbis using oggenc, you might encounter the following error:
"ERROR: Input file <file> is not a supported format"
Explanation
One possible reason for this can be an ID3 tag in the flac file. This can happen if the program you used to create your FLAC files uses ID3 tags instead of native FLAC tags to store metadata.