Why Audio files tagged with itunes player have COMMENT:ITUNSMPB and COMMENT:ITUNNORM keys values are not readable format?

Question

I am extracting embedded ID3 tags from an audio file that has keys.I am using pytaglib and extracted information looks as below:

{ u'ALBUM': [u'Instrumental Bhajan'], 
  u'INITIALKEY': [u'C'],
  u'COPYRIGHT': [u'Radio'],
  u'ARTIST': [u'Radio],
  u'COMMENT:ITUNNORM': [u' 000003BF 000003BC 00002593 00002441 00032FE8 000337F8 00007D4C 00007F62 000189A8 000396F0'],
  u'BPM': [u'75'],
  u'COMMENT:ITUNSMPB': [u' 00000000 00000210 00000920 0000000000D4DCD0 00000000 00B14E00 00000000 00000000 00000000 00000000 00000000 00000000'],
  u'GENRE': [u'devotional, instrumental'], 
  u'TITLE': [u'Bhajare Ram Charan'], 
  u'ENCODING': [u'Logic Pro 9.1.8'], 
  u'DATE': [u'2015'],
  u'LABEL': [u'Radio]}

My code is very simple one:

Whose output is: Extracted Tags

{u'ALBUM': [u'Instrumental Bhajan'],
 u'INITIALKEY': [u'C'],
 u'COPYRIGHT': [u'Radio'], 
 u'ARTIST': [u'Radio'],
 u'COMMENT:ITUNNORM': [u' 000003BF 000003BC 00002593 00002441 00032FE8 000337F8 00007D4C 00007F62 000189A8 000396F0'],
 u'BPM': [u'75'], 
 u'COMMENT:ITUNSMPB': [u' 00000000 00000210 00000920 0000000000D4DCD0 00000000 00B14E00 00000000 00000000 00000000 00000000 00000000 00000000'],
 u'GENRE': [u'devotional, instrumental'], 
 u'TITLE': [u'Bhajare Ram Charan'],
 u'ENCODING': [u'Logic Pro 9.1.8'], 
 u'DATE': [u'2015'], 
 u'LABEL': [u'Radio']}

I am not able to find why these to keys are comming in not readable format?

import taglib
sosng = taglib.File("Bhajare-Ram-Charan-instrumental-bhajan-radio.mp3")
sosng.tags

Answer 1

iTunes Seamless Playback: 8 bytes are for priming, that should be removed, 4 bytes trailing (remainder) that should be removed, next 8 bytes are for total samples (not including trailing samples and priming samples) and lastly 8 bytes are used for byte offset from the first audio frame to the 8th-from-last frame (resynchronization mechanism to restore a decoder's true sample number after a seek), 24 bytes are not used. Totally 52 bytes.

https://ffmpeg.org/pipermail/ffmpeg-devel/2012-July/127834.html

https://hydrogenaud.io/index.php?topic=48231.msg430949#msg430949

https://git.rockbox.org/cgit/rockbox.git/log/?qt=grep&q=gapless