That depends, what type of sound are you planning to get the frequency of?
Is it just a pure waveform like a sine or triangle wave or something more complex?
You are right that if you want to do this in DBPro you would use a memblock as a means of reading the actual audio data. To extract the frequency of a pure waveform from this you could simply check at what interval the sampled values goes from 0 into the positives (or negatives); the samples will pass zero once on the way up and again on the way down so you want to make sure that you check where it has gone full circle, that is every two passes past zero.
If on the other hand you want to find the dominant frequency in a more complex waveform this approach won't be sufficient. You can google for
pitch tracking which is the technical term for what you want to achieve in this case.
Finally, if you just want to know the fixed sampling frequency of the sound, this is stored as a DWORD at offset 8 in the sound memblock.
"Why do programmers get Halloween and Christmas mixed up?" Because Oct(31) = Dec(25)
