I’m pretty sure if you rip CDs directly to FLAC, it’s a perfect copy assuming you’re using good software. PCM isn’t lossy or lossless because it’s not a compressed format, it’s an uncompressed bitstream. Think of it like the original data. If it was burned to a CD as digital MP3 data and then ripped that to FLAC, then yes you’d be going from lossy compressed to lossless, which would hide the fact that quality was lost when it went to MP3 in the first place.
Just as an example, you can rip a CD directly to FLAC (you should also find and use the correct sample offset for your CD drive), rip the cue sheet for track alignment, then burn the FLAC back to a new CD using the cuesheet (and the correct write offset configuration), and you’ll get a CD with the exact bit for bit pattern of “pits” burned into the data layer.
You can then rip both CDs to a raw uncompressed wav file (wav is basically just a container for PCM data) and then you’ll be able to MD5sum both wav files and see that they are identical.
This is how I test my FLAC rips to make sure I’m preserving everything. This is also how CD checksum databases (like CDDB) work - people across the globe can rip to wav or flac and because it’s the same master of the CD, they’ll get identical checksums, and even after converting the PCM/wav into a flac you are still able to checksum and verify it’s identical bit for bit.
Ignorant of the subject matter, but I ripped a bunch of CDs to FLAC some time ago. Would that not work for this purpose?
Audio CDs contain 44.1kHz 16-bit PCM. If you got FLACs out you transcoded them, and transcoding from lossy to lossless is generally undesirable
EDIT: I stand corrected, I forgot that PCM is not a codec.
I’m pretty sure if you rip CDs directly to FLAC, it’s a perfect copy assuming you’re using good software. PCM isn’t lossy or lossless because it’s not a compressed format, it’s an uncompressed bitstream. Think of it like the original data. If it was burned to a CD as digital MP3 data and then ripped that to FLAC, then yes you’d be going from lossy compressed to lossless, which would hide the fact that quality was lost when it went to MP3 in the first place.
Just as an example, you can rip a CD directly to FLAC (you should also find and use the correct sample offset for your CD drive), rip the cue sheet for track alignment, then burn the FLAC back to a new CD using the cuesheet (and the correct write offset configuration), and you’ll get a CD with the exact bit for bit pattern of “pits” burned into the data layer.
You can then rip both CDs to a raw uncompressed wav file (wav is basically just a container for PCM data) and then you’ll be able to MD5sum both wav files and see that they are identical.
This is how I test my FLAC rips to make sure I’m preserving everything. This is also how CD checksum databases (like CDDB) work - people across the globe can rip to wav or flac and because it’s the same master of the CD, they’ll get identical checksums, and even after converting the PCM/wav into a flac you are still able to checksum and verify it’s identical bit for bit.