Re: [linux-audio-dev] Algorithm for displaying waveforms

From: vanDongen/Gilcher <gml@email-addr-hidden>
Date: Mon Jun 06 2005 - 15:14:41 EEST

On Monday 06 June 2005 10:04, Alfons Adriaensen wrote:

> The most difficult situation is for n nearly equal to one.
>
> But even this is not really correct if you want precision.
>
> Consider an Fs/4 sine with samples -0.9 -0.9 +0.9 +0.9 -0.9 -0.9 +0.9 etc.
> Now what is the (peak) amplitude of this sine ? Not 0.9, but something like
> 1.27. If you send this signal through a unity gain filter that produces 45
> degrees of phase shift, you will get samples at +/- 1.27, and your DAC will
> clip.
>
> So even a simle digital peak meter requires interpolation of peaks to
> be accurate. I don't know any in the linux world that do this.

Good points.
What kind of interpolation is required to visualize the DAC output of a
sampled waveform?

Gerard
Received on Mon Jun 6 16:15:08 2005

This archive was generated by hypermail 2.1.8 : Mon Jun 06 2005 - 16:15:09 EEST