Re: Please write audio tests (was: Playing ULAW sample correctly?)

[David Laight]

On Tue, Nov 03, 2009 at 07:48:29PM +0200, Damjan Jovanovic wrote:
> On Tue, Nov 3, 2009 at 3:33 PM,   wrote:
> > Wine would benefit from a test in msacm32/tests/ sketched as follows:
> > 0. choose some base frequency like 11025Hz;
> > - generate a PCM sine wave tone (like winmm/tests/wave.c);
> > - convert it to ?-law via the ACM functions;
> > - play it via winmm if wine_interactive is set (like in wave.c)
> > - convert it back and apply some delta function to tell if it's
> >
> > ? close enough to the original sine,
> > ? i.e. mechanically verify that the round-trip worked.
>
> You'd need to verify the energy in the discrete Fourier transform of
> the signal at the frequency you're testing for, is say 90% of the
> total signal energy.

Or use a goertzel detector for the transmitted tone(s).
It is also quite simple to generate sine waves without any trig.

David