Try running your library through Fakin The Funk. Source: almost 2 years ago

Spek and Fakin' the Funk are two tools that will tell you what you've truly got; Audacity will also do it if you ask it for a frequency analysis. If your mp3 has a hard shelf at 16kHz, it's a 128, no matter what the file says it is. Source: almost 2 years ago

I had the same problem. Fakin' The Funk (here) was the perfect solution for that. Source: over 2 years ago

Yeah I found it here https://fakinthefunk.net/en/. Source: over 2 years ago

I was using this: https://fakinthefunk.net/en/ Is this reliable? Source: over 3 years ago

I found a tool named [Lossless Audio Checker](https://losslessaudiochecker.com) : "A utility to check whether a WAVE or FLAC file is truly lossless or not". I was so sad that this project is not open-source but their Research papers give some interesting clues about detecting bad quality files. On my side, I used it through a [Bash script](https://gist.github.com/madeindjs/d5e3949313b141f2e5eea62b982c2a02) to... - Source: Hacker News / 5 months ago

Yeah, sure. I use Lossless Audio Checker, which is single threaded but seems to generate fewer false negatives. That is to say it's slow, but doesn't flag genuine lossless files as probable mpegs as much. My biggest beef with LAC is how annoying it is about its log files. It doesn't save them in the folder with the FLACs so I have to manually copy every log file from my Documents folder to the proper location.... Source: over 1 year ago

You can use this to check for artificially inflated bitrate/bitdepth, its fairly accurate, or fbits which can detect exactly how much of the bitdepth is being used. Source: over 2 years ago

If you have Windows, the Lossless Audio Checker can tell you in about 2 seconds if a WAV or FLAC file has been upsampled/ upscaled/ transcoded. There is also a CLI version for Mac. Source: over 3 years ago

Losslessaudiochecker.com paired with spek.cc when in doubt gets the job done. Source: over 3 years ago