Watermarking: what do we know?

[111MilesToGo]

Addendum to my post #56 above: I did now compare purchased (in 2018) tracks from four download stores, HighResAudio, HDTracks, Acoustic Sounds, and Presto. I couldn‘t find any difference between any two stores to yield a null all over the frequency band. Very bad result given this is all purchased music!

I will try three approaches when my time allows:

• If mattmontag is correct in saying (April 2020) that all UMGs are clean now, one can hope that the stores replace their files. I‘ll check whether a store allows me to re-download those older purchases of mine. But then, how to find out whether I‘m getting a clean copy now?
• I might check how a purchased downloaded CD quality file compares to a dBpoweramp AccurateRip of an original physical CD. The AccurateRip fingerprint or the flac audio checksum will be the easiest things to do.
• The most difficult thing to do with DeltaWave will be to evaluate the difference between a purchased downloaded hi-res file and its physical CD rip. Most of the time, those will be different masters; and even if they are from the same mastering, it might be challenging to align them perfectly.

I will report back. Happy to receive hints and recommendations from you.

Remark: I did not look into streaming services (yet).

 

[adam2434]

Not sure if this is the best place to post this.

Does anyone have the interest and capability to take a CD FLAC rip and the same FLAC track on Tidal and capture/compare the Chromecast Audio digital output bitstream for both.

One would have a make their best educated assumption that the CD and the Tidal FLAC track are from the same label release/master by looking at the label, release date, etc.

If the two bitstreams from the Chromecast Audio are identical, then I think one could assume that the Tidal FLAC track is identical to the CD and that the Chromecast Audio is passing it bit-perfect.

 

[Katji]

hmmm, @sajunky particularly concerned about this. ...No longer around, neither here nor there...

Everything you stream is watermarked, It doesn't depend on the streaming service, but a label supplying a stream. Some labels use very robust method, it is designed to survive MP3 compression, so is audible.

In addition, they frequently fail to dither properly when converting from hi-res format to 16-bits, resulting poor tonality and harshness on the top end.

Most of downloaded content is also watermarked, it also depend on a label. If doubt, read the Amazon T&C, they mention something (in a slightly obfuscated way).

 

[Belker]

I found this thread and made some tests. I don't have a lot of classical in my old and ripped CD collection, but I found two DG albums.
Karajan/Bach: https://open.qobuz.com/album/0002894594602
Karajan/Mozart: https://open.qobuz.com/album/0002894198672

I downloaded them and made a null compare with DeltaWave. Both were bit perfect. So either the CDs are watermarked as well, or the Qobuz files are clean.

 

[sarumbear]

Do any of you know what app would have been used to create this spectrograph? I might be onto something more with being able to look at watermarks.

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