On Thu, Jan 30, 2014 at 5:35 PM, keenerd keenerd@gmail.com wrote:
On 1/30/14, keenerd keenerd@gmail.com wrote:
On 1/30/14, Anders Lynge Esbensen anders@lyes.dk wrote:
I've implemented a faster FM demodulator for rlt_fm.
Let me see if I can get a fixed-point version written.
I've cleaned it up and it is in my repo. You can enable it with "-A ale" https://github.com/keenerd/rtl-sdr/commit/025fb56dff98
Some quick benchmarks: std: 10% fast: 7% lut: 7% ale: 7%
Sound quality is also noticably worse with ale, but that might be from an error in the fixed point conversion. How does the math look to you?
I have also be playing around with the atan demodulators. gnuradio uses fast-atan tables instead of the libC version. I dunno how libc implements it, but they could be worth considering...
Nikos
-Kyle http://kmkeen.com