Originally Posted by jimray
Is it possible that a flac file could be made incorrectly? Or, if I have a flac file, I can rest easy it's actually lossless.
I want to start the process of replacing my MP3's with flacs, just want to make sure I don't make any mistakes.
A FLAC file is a lossless representation of the source. If your source was an MP3, the FLAC file resulting from encoding it will be 100% identical to the unpacked (decoded) waveform of the MP3 file.
Usually, the tell-tale is looking at the frequency response graph of an audio file, the MP3 will not have as wide a response as its FLAC counterpart (if they are both encoded from the same source).
The source can also make a huge difference, not all CDs are created equal (mainly AAD vs DDD or even ADD).
And unless you have a log provided with the files (that is, you didn't rip the CD yourself) there is no way to be 100% sure the FLAC was not encoded from an MP3.