Fréquence coupure mp3

[FUNKYGUIZMO]

Bonjour,
Sur plusieurs sites,  on explique qu'un mp3 de 320 kbps coupe à 20,5 khz et un mp3 de 256 kbps coupe à 20 khz. Sur votre logiciel,  j'ai des mp3 déclarés 320 kbps à 19,7 et des 256 à 19,2.  Pouvez vous m'éclairer ? Est ce normal ? Comment votre logiciel détermine t'il la qualité du mp3 ? Quand je scanne mes fichiers,  je coche l'option 1 et l'option 2.Sinon, comment optimiser les résultats du logiciel ? Quelles options choisir ?
 Merci par avance. Nicolas

[Fake No Funk]

Bonjour Nicolas,

malheureusement, je ne parle pas bien francais, so I prefer to answer in english :)

Firstly, there is no *exact* cutoff at a special frequency and it is often hard to decide whether it is 320 or 256 kbps.
Fakin' The Funk does a tolerant analysis and chooses the bitrate that is closest to the detected cutoff frequency.

Secondly, always keep in mind, that 99.9% of the audience cannot distinguish between 320 or 256 kbps, since almost every codec becomes transparent at already (slightly above) 192 kbps, see https://en.wikipedia.org/wiki/Transparency_(data_compression)

Therefore, there is an option in the settings dialog whether to report fakes above 256 kbps or not:
(Please note: This will only suppress files whoes detected bitrate is above 256, it does not rely on the claimed value from the file properties)
 

Maybe this is already the cause for your confusions?

But if you want to inspect the suspicious files yourself, you can always sort the analyzed files by the detected frequency in the listview!

Kind regards
Ulrich

[FUNKYGUIZMO]

Ok Thanks for precisions.
Yet,  I would like to Know where the software consideres  mp3 has a 256 kbps bitrate.  As I said you,  I see on the net that frequency cutoff is 20khz. For you,  it's 19 ? Same for 320 kbps.I hope I'm clear.  
And for optimisation, you advise me to choose what options in analyse ? Thanks !

[Fake No Funk]

Max. Freq. > 19,.75 kHz ==> 320 kbps  
Max. Freq. > 19.05 kHz ==> 256 kbps

[FUNKYGUIZMO]

Ok Thank you friend 😀