[linux-audio-dev] Algorithm for displaying waveforms

[Alfons Adriaensen]

On Mon, Jun 06, 2005 at 12:14:41PM +0000, vanDongen/Gilcher wrote:

> What kind of interpolation is required to visualize the DAC output of a 
> sampled waveform?

This depends mostly on the maximum frequency you want to display or
measure accurately, and on the level of accuracy required.

You can get a long way by just detecting those points in your waveform
where the 'continuous' signal would exceed nearby samples, and try to
approximate the real peak value using e.g. cubic interpolation.

I'm working on a scope program as a companion to JAAA. The current
baseline is an 8 point convolution based interpolation to 4 Fs, and
linear from there on. The precision is needed mostly for finding the
trigger points accurately.

-- 
FA