Changes between Version 2 and Version 3 of Tone_Generator
 Timestamp:
 Sep 18, 2008 1:21:15 PM (14 years ago)
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Tone_Generator
v2 v3 8 8  {{{PJMEDIA_TONEGEN_SINE}}}: The goodold generation using math's sine(), floating point. This has very good precision but it's the slowest and requires floating point support and linking with the math library. 9 9  {{{PJMEDIA_TONEGEN_FLOATING_POINT}}}: Floating point approximation of sine(). This has relatively good precision and much faster than plain sine(), but it requires floatingpoint support and linking with the math library. 10  {{{PJMEDIA_TONEGEN_FIXED_POINT_CORDIC}}} (new in 1.0rc3): Fixed point using sine signal generated by Cordic algorithm. This algorithm can be tuned to provide balance between precision and performance by tuning the {{{PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP}}} setting, and may be suitable for platforms that lack floatingpoint support. 10  {{{PJMEDIA_TONEGEN_FIXED_POINT_CORDIC}}} (new in 1.0rc3): Fixed point using sine signal generated by Cordic algorithm. This algorithm can be tuned to provide balance between precision and performance by tuning the {{{PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP}}} setting, and may be suitable for platforms that lack floatingpoint support. The default setting for {{{PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP}}} is 8. 11 11  {{{PJMEDIA_TONEGEN_FAST_FIXED_POINT}}}: Fast fixed point using some approximation to generate sine waves. The tone generated by this algorithm is not very precise, however the algorithm is very fast. 12 12 … … 31 31 32 32  PJMEDIA_TONEGEN_SINE:[[BR]] [[Image(sine.JPG)]]  PJMEDIA_TONEGEN_FLOATING_POINT:[[BR]] [[Image(float.JPG)]]  33  PJMEDIA_TONEGEN_FIXED_POINT_CORDIC with 10 iterations:[[BR]] [[Image(cordic10.JPG)]]  PJMEDIA_TONEGEN_FIXED_POINT_CORDIC with 8 iterations :[[BR]][[Image(cordic8.JPG)]] 33  PJMEDIA_TONEGEN_FIXED_POINT_CORDIC with 10 iterations:[[BR]] [[Image(cordic10.JPG)]]  PJMEDIA_TONEGEN_FIXED_POINT_CORDIC with 8 iterations (default):[[BR]][[Image(cordic8.JPG)]]  34 34  PJMEDIA_TONEGEN_FIXED_POINT_CORDIC with 7 iterations:[[BR]] [[Image(cordic7.JPG)]]  PJMEDIA_TONEGEN_FAST_FIXED_POINT: [[BR]][[Image(fastfixedpoint.JPG)]]  35 35 36 36 37 == Performance == 38 39 Below is the time measurements of the algorithms. The test measures the generation of 1 second worth of dualtone at 8KHz sampling rate. For singletone, just divide the results by two, and for 16KHz dualtone, just multiply the results by two. 40 41 The MIPS value uses the same convention as in [PJMEDIAMIPS PJMEDIA Performance Measurement] page. 42 43 === Linux, ARM9 (ARM926EJS), gcc === 44 45 On this platform we use {{{O3 msoftfloat DNDEBUG DPJ_HAS_FLOATING_POINT=0}}} flags. 46 47   time (usec)  CPU (%)  MIPS  48  PJMEDIA_TONEGEN_SINE  506,535  50.653  100.29  49  PJMEDIA_TONEGEN_FLOATING_POINT  18,037  1.804  3.57  50  PJMEDIA_TONEGEN_FIXED_POINT_CORDIC with 10 iterations  11,662  1.166  2.31  51  PJMEDIA_TONEGEN_FIXED_POINT_CORDIC with 8 iterations (default)  9,872  0.987  1.95  52  PJMEDIA_TONEGEN_FIXED_POINT_CORDIC with 7 iterations  8,943  0.894  1.77  53  PJMEDIA_TONEGEN_FAST_FIXED_POINT  1,449  0.145  0.29  54