I got an Amazon gift card as birthday present and thus had to spend that money somehow. In the end I bought a music album I did not yet possess as .mp3 files.
Originally I wanted to know if the professionally created mp3 files contain embedded lyrics, and so I looked at the meta data:
$ id3v2 -R 01\ -\ Tim\ McGraw.mp3 PRIV: (unimplemented) TIT2: Tim McGraw TPE1: Taylor Swift TALB: Taylor Swift TCON: Country (2) TCOM: TPE3: TRCK: 1/15 TYER: 2008 TPE2: Taylor Swift COMM: ()[eng]: Amazon.com Song ID: 208225224 TCOP: © 2008 Big Machine Records, LLC TPOS: 1/1 APIC: ()[, 3]: image/jpeg, 315095 bytes 01 - Tim McGraw.mp3: No ID3v1 tag
The PRIV did alert me, and an internet search gave two blog posts that explained the issue:
- Amazon AutoRip und die Wasserzeichen, 2013
- Removing Personal Information from MP3s bought on Amazon, 2017
I could extract the XML with exiftool:
exiftool -Private -b 01\ -\ Tim\ McGraw.mp3 |xmllint --format - <?xml version="1.0" encoding="UTF-8"?> <uits:UITS xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:uits="http://www.udirector.net/schemas/2009/uits/1.1"> <metadata> <nonce>EK5M23vD</nonce> <Distributor>Amazon.com</Distributor> <Time>1970-01-01T00:00:00Z</Time> <ProductID type="UPC" completed="true">00602517874695</ProductID> <AssetID type="ISRC">USCJY0603008</AssetID> <TID version="1">0683844761475530868664102416XXXX</TID> <Media algorithm="SHA256">8eb80bb9028cbb6caf122dd4984c2b823b82aa0b2cf22b61a369187567dc0ffe</Media> <PA>unspecified</PA> <Copyright/> <Extra type="TransactionType">Download - Paid</Extra> </metadata> <signature algorithm="RSA2048" canonicalization="none" keyID="dd0af29b41cd7d6d82593caf1ba9eaa6b756383f">XXXXXXXX==</signature> </uits:UITS>
So the mp3 can be traced back to me if my computer gets stolen/hacked and the files are uploaded somewhere. A watermark, just as some e-books have them.
I removed the PRIV frames with:
$ eyeD3 --remove-frame PRIV *.mp3
Audio marks
I did not know this until writing this blog post, but some files have watermarks embedded in the sound itself: Universal's Audible Watermark.