That is exactly the problem... keeping a unique "file identifier" while changing everything else (date, size, location)... hashing is a slow but pretty accurate

That is exactly the problem... keeping a unique "file identifier" while changing everything else (date, size, location)... hashing is a slow but pretty accurate approach for this. But maybe not the best / right one. There is also `chromaprint`[1] in ffmpeg - maybe this can be utilized, too... but I still think it is too slow. I think I have to test this out and provide the "don't lose your history" as experimental approach. Performance is king... especially when indexing or importing. Nobody wants to wait 3 days until his library is indexed :-) [1]: http://underpop.online.fr/f/ffmpeg/help/chromaprint-1.htm.gz http://underpop.online.fr/f/ffmpeg/help/chromaprint-1.htm.gz