[Portaudio] loopback test is finding some bugs

[Phil Burk]

Hi Chris,

> If I'm reading your test results correctly, it appears all of your
> pops occur at 44.1 kHz. Is this simply the result of the way your
> test is set up?

I only test buffer sizes at 44100.

In the loopback test I scan all the sample rates with 
freamesPerBuffer=0.  Then I scan a bunch of buffer sizes with 
sampleRate=44100.  You can override the bufferSize and/or sampleRate.

I used to scan every combination of sampleRate+framesPerBuffer but it 
took too long. I may add that back as an option. It's easy to change the 
high level test pattern now that the DSP code is working. I may add 
these features:

--complete , complete matrix of possible combinations of settings

--duration=# , duration in seconds for each capture.

--interleaved , only test using interleaved buffer (currentl default)

--nonInterleaved , only test using nonInterleaved buffers

--fullDuplex , only (currently test both half and full)

--halfDuplex , only

I may also add a scan over a range of latency settings, or maybe a 
binary search for the lowest latency setting that does not pop...

--searchLatency

Other ideas?

Phil