Qtek S100 audio hardware ...

[ryhor]

Hi!

Could someone tell me what a hardware audio codec is used "inside" this device? I mean what chip is used for A/D D/A conversion in audio part. I am sure someone has already opened device.

Shortly - the problem is - in speed of operation (conversion) of waveIn and waveOut subsystem.
we are using 8kHz WAVE_FORMAT_PCM settings and
- Qtek s100 has 1.6% difference in speed of operation of OUT an IN subsystem.
- HP2210 has only 0.005% difference.

Question is simple - why? if codec (chip) has been clocked by single oscillator - how can we have such big difference in operation speed of A/D and D/A convertions - in case of Qtek?

Second question - is it hardware or software (audio drivers) problem?

what we wanna do - try to use other sample rate - maybe it will help us to achieve acceptable difference in operation speed.

[ryhor]

a bit more details.
"Investigation" shows that
- Qtek S100 has same speed of operation of wave_IN and wave_OUT subsystem only if 44.1kHz sample rate is specified. in all other cases one of devices (IN or OUT) are working faster (produce or consume more samples) aproximately on 1-1.6%.

- irregularity of wave_X done/data_ready events or messaging is just terrible even if you "request" 2 times per second "communication" with wave device.

So it looks like OS porting or at least audio drivers in Qtek s100 was made in very bad manner.

HP 2210 on my desk working just fine - everything works as it is expected .