Watermarks in Amazon .mp3 files

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)
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:

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">
    <ProductID type="UPC" completed="true">00602517874695</ProductID>
    <AssetID type="ISRC">USCJY0603008</AssetID>
    <TID version="1">0683844761475530868664102416XXXX</TID>
    <Media algorithm="SHA256">8eb80bb9028cbb6caf122dd4984c2b823b82aa0b2cf22b61a369187567dc0ffe</Media>
    <Extra type="TransactionType">Download - Paid</Extra>
  <signature algorithm="RSA2048" canonicalization="none" keyID="dd0af29b41cd7d6d82593caf1ba9eaa6b756383f">XXXXXXXX==</signature>

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.

Written by Christian Weiske.

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