[mad-user] Clipping - Some naive (?) questions
Wed, 14 Feb 2001 00:05:23 -0500
this is what I assume:
in downsampling from whatever medium the recording was made (24-bit, 96Khz, for example), to keep the dynamic range of the recording at it's fullest, whoever masters the CD will normalise the audio to peak of the 16-bit range. I would hope that even though samples exist at the edges of the range (reported as "possibly clipped samples" by cool edit pro), the true shape of the waveform is not clipped, but just touches the amplitude limit.
are you suggesting is that the encoding process (in some/most cases) furthar distorts the waveform so that it is clipped beyond the max amplitude of the 16-bit range?
... ah decided to check out your page before pressing send.
I now see how clipping when normailizing to peak *can* occur.
> At 06:12 PM 2/13/01 +0000, D D wrote:
> >I'm a new user to MAD and it's immediately become my standard for mp3
> >and decoding. The first thing that shook me when using Mad, was something
> >that I
> >never had encountered before, the mp3 clipping indicator. Low-bit
> >distortion is
> >one thing, but high-bit problems is surely a worse one, if not the worst! And
> >when I witnessed Mad reports clipping even with files produced by the best
> >encoders like Lame, this rang a red alert for me: are we constantly
> >exposed to
> >clipping distortion when using winamp's decoder or other decoding apps?
> Yes, and the more recent the music, the more likely it is that your average
> mp3 is clipping, since record producers these days seem intent on
> compressing the life out of their recordings to increase average
> volume. Yuck. The mp3 encoding process can add even more clipping, making
> a bad situation worse. The best solution is to normalize to less than full
> scale *before* encoding. See my page:
> for a discussion on the audibility of clipping introduced by encoding to mp3.