What is the most efficient pitch detection algorithms in terms of computation? I need something to implement on a DSP. The typical signal in my situation would be a mixture of low-level wide-band noise plus a series of strong harmonics below 1000 Hz (think of the noise produced by industrial machinery or by car engines). The system needs to sample ("know") the current fundamental frequency of the signal every second or so.
YINS fft is the best method that worked for me in the past. I have my open source implementation of it written in awesome D language: link . I compared the results with Praat they match.