I'm currently using the waveInOpen set of Windows API functions to record audio for a VOIP application. I'm now being asked to add echo cancellation, and possibly noise reduction, and gain control. I know nothing about DirectSound, but while searching on "echo cancellation" on Google I came across references on MSDN to DirectSound such as CaptureAcousticEchoCancellationEffect.
If I switch to DirectSound will I get some of these features "for free"? Are they only supported if the hardware supports it, and if so, how often will that hardware be present in the average consumer PC?