From 6ba5f59841d575ad8011d53d6a5e18780ca15087 Mon Sep 17 00:00:00 2001
From: Benny Prijono <bennylp@teluu.com>
Date: Thu, 18 Sep 2008 14:11:29 +0000
Subject: [PATCH] More ticket #619: changed default Cordic loop from 8 to 10 to
 gain more accuracy, and updated tonegen.c with the results from ARM9 tests

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@2294 74dad513-b988-da41-8d7b-12977e46ad98
---
 pjmedia/include/pjmedia/config.h |  8 +++++---
 pjmedia/src/pjmedia/tonegen.c    | 12 ++++++++++++
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/pjmedia/include/pjmedia/config.h b/pjmedia/include/pjmedia/config.h
index 86a408e90..2f008dadf 100644
--- a/pjmedia/include/pjmedia/config.h
+++ b/pjmedia/include/pjmedia/config.h
@@ -577,7 +577,9 @@
 
 
 /**
- * Specify the tone generator algorithm to be used.
+ * Specify the tone generator algorithm to be used. Please see 
+ * http://trac.pjsip.org/repos/wiki/Tone_Generator for the performance
+ * analysis results of the various tone generator algorithms.
  *
  * Default value:
  *  - PJMEDIA_TONEGEN_FLOATING_POINT when PJ_HAS_FLOATING_POINT is set
@@ -600,10 +602,10 @@
  *
  * Valid values are 1 to 28.
  *
- * Default value: 7
+ * Default value: 10
  */
 #ifndef PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP
-#   define PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP  7
+#   define PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP  10
 #endif
 
 
diff --git a/pjmedia/src/pjmedia/tonegen.c b/pjmedia/src/pjmedia/tonegen.c
index 3f2cbe370..152ff913b 100644
--- a/pjmedia/src/pjmedia/tonegen.c
+++ b/pjmedia/src/pjmedia/tonegen.c
@@ -40,6 +40,8 @@
      * This is the good old tone generator using sin().
      * Speed = 1347 usec to generate 1 second, 8KHz dual-tones (2.66GHz P4).
      *         approx. 10.91 MIPS
+     *
+     *         506,535 usec/100.29 MIPS on ARM926EJ-S.
      */
     struct gen
     {
@@ -65,6 +67,8 @@
      * the normal sin() generator.
      * Speed = 350 usec to generate 1 second, 8KHz dual-tones (2.66GHz P4).
      *         approx. 2.84 MIPS
+     *
+     *         18,037 usec/3.57 MIPS on ARM926EJ-S.
      */
     struct gen
     {
@@ -84,6 +88,12 @@
      * Speed = 742 usec to generate 1 second, 8KHz dual-tones (2.66GHz P4).
      *         (PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP=7)
      *         approx. 6.01 MIPS
+     *
+     *         ARM926EJ-S results:
+     *	        loop=7:   8,943 usec/1.77 MIPS
+     *		loop=8:   9,872 usec/1.95 MIPS
+     *          loop=10: 11,662 usec/2.31 MIPS
+     *          loop=12: 13,561 usec/2.69 MIPS
      */
     #define CORDIC_1K		0x026DD3B6
     #define CORDIC_HALF_PI	0x06487ED5
@@ -184,6 +194,8 @@
      * Quality wise not so good, but it's blazing fast!
      * Speed = 117 usec to generate 1 second, 8KHz dual-tones (2.66GHz P4).
      *         approx. 0.95 MIPS
+     *
+     *         1,449 usec/0.29 MIPS on ARM926EJ-S.
      */
     PJ_INLINE(int) approximate_sin3(unsigned x)
     {