distortion still an issue

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Martin Hairer
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distortion still an issue

Post by Martin Hairer »

Are you using version 2.0.3? Previous versions had a bug which would cause some
additional distortion if you encode an Mp4 file containing samples that fall outside of
the [-1,1] range. (Which is what will happen if you normalise to a positive value and why
one actually shouldn't do that...) Regards,

Martin

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CDJonah_alt
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Joined: Thu Mar 15, 2007 3:57 pm

distortion still an issue

Post by CDJonah_alt »

Listening to the sample, it is still clipping, which is, of course, what one would expect if you normalize to +1 dB.

The instructions I gave said set to normalize to 0 dB and not +1 dB. It might not show up in other conversions because it is conceivable that other conversions may round off the clipping -- the mp3 may be a more accurate conversion.

As Sarah says, you can't go above 0dB. There are a few cases where one might want to normalize so that it is clipped, but if you don't understand why you might want to do it, you shouldn't do it.

Chuck

On 8/6/11 9:20 AM, Sarah Alawami wrote:
Actually in rereading that you should *not* normalize to +1db, ever! always always always normalize to 0. Nothing can and never will go higher then that. 0 is the top of the fairer shall we say.
On Aug 5, 2011, at 11:57 PM, Ray Foret Jr wrote:
Okay.

What I have on offer now are two files.


The first one is the original file.


http://dl.dropbox.com/u/13790727/01%20Opening%20Title.mp3


The next file is the exact same file but normalized to +1DBSPL using maximal sample values after having been converted to stereo and saved as an mp3 file coded at 128KBPS at 44.1KHZ.


http://dl.dropbox.com/u/13790727/01%20Opening%20Title%20Normalized%20to%20plus1DB%20Using%20Maximal%20Sample%20Value.mp3




It's my belief that there is an issue with the mp3 encoding process as the same distortion does not occur when the file is processed in the way described above and saved as a .m4a or .wav file.


Thoughts?



Sincerely, The Constantly Barefooted Ray!!!


Now a very proud and happy Mac user!!!


Skype name:
barefootedray


Facebook:
facebook.com/ray.foretjr.1







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