These guys (Monty and others) are engineers, not PR agents! When they say lossless, they simply mean it. If there are exceptions to this promise, they'd be mentioned in big red letters and nobody would mention lossless in the first place! With engineers, it's really that simple.
An error would be so easy to demonstrate, ..mhh well... just why nobody does it?!
One counter-example and you earn eternal internet fame of having debunked a big scam. But until this happens, why trust anybody else? After all, FLAC started with a mathematical proof, which you can verify on your own. Or simply let the encoding test itself (as mentioned above), it's 100% fool proof.
Last edited by FabienTDR; 28th October 2018 at 08:58 PM..
I use iZotope RX 7 and Rogue Amoeba Fission - they both support batch conversion to FLAC. RX 7 offers bit depth, dither and compression level settings.
I've heard that, and I've also heard stories of people getting clipping, altered levels or altered sound from some encoders...
IF they do that then they are NOT using the FLAC encoder!!! It is very easy to test with a round trip from wav to FLAC back to wav - and to get a total null of the final wav with the first one in a null test.