So Deezer’s website itself states that it provides “unlimited access to 36 million high fidelity, CD-quality lossless tracks (16-Bit/44.1 kHz FLAC)”
I’m not aware of their workflow, but doesn’t this mean that a rip from Deezer should have the same raw wav that a CD rip does? There are some albums here that I’ve compared the CD rip to the Deezer versions and found that their md5 and crc’s don’t actually match. Deezer rips often tend to be larger for some reason too.
If anyone else happens to know what’s happening I would really appreciate it. When matching releases on MusicBrainz, I’d rather not use the Deezer versions if they are not in fact the same as the CD release. I’ve been going off the assumption that they are identical.
“CD-quality” means it has the same audio quality specifications as CD audio (lossless, 16-Bit/44.1 kHz, as they state), not that they are sourced from actual CDs. Anything from Deezer should certainly be marked as WEB.
Larger files are likely due to embedded images or a lower FLAC compression level.
CD quality means exactly that – the files are 16bit, 44.1kHz. They probably aren’t going around ripping CDs, and nobody guarantees the mastering on the CDs and the Deezer version is the same.
Funnily enough, I was conducting a similar exercise a couple months ago, and ran into similar issues. The CRC comparison is being thrown off because there are often differences in the amount of silence (and “quasi-silence”) at the beginning and/or end of tracks. In other words, if you trim silence from the beginning + end of both sources, and make sure to align both the audio data (e.g. w/ Audacity), it often matches. There will always be exceptions, though I found them to be rare. At least, that’s been my experience when comparing CD vs. Deezer vs. Qobuz for 2018 and 2019 releases.
FWIW, I used SoX and Audacity. If you have an example release where both the Deezer and 100% CD are here on RED, we can sleuth further. I’d be game to join you in that endeavor. Either way, good luck!