Processing a sine wave file
Hi, I am just wondering if anyone could point me in the right direction with this. I have a sound recording off a phone line, which is taken at the very beginning of a call. It is in the windows standard wave format. Now, I need to be able to determine when I have a new cycle, and the duration of this cycle in ss:mm. Additionally, from this data I also need to be able to determine the frequency of the wave file. I think the formula for calculating the frequency is 1/t (the time of the cycle?) This will be a sine wave.
I have never processed a wave file before, and I was going to use memory mapping to do this instead of working on several different buffers. However, I am uncertain as to how to calculate the cycles and the frequency. Could anyone give me any advise on this? Another thing, when you are reading in the data from the data section of the wave file, how does it represent negative voltages, does it use signed ints (so I would need an array of signed ints)?