Large reorganization of the tonegen for ticket #619:

 - Deprecate the automatic selection of algorithm
 - Introduced various constants for tonegen backends
 - Allow user to specify/override the algorithm by setting
 - Fix the floating-point approximation backend



git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@2292 74dad513-b988-da41-8d7b-12977e46ad98

1 files changed, 65 insertions, 30 deletions

diff --git a/pjmedia/include/pjmedia/config.h b/pjmedia/include/pjmedia/config.h
index 70354ee7..86a408e9 100644
--- a/pjmedia/include/pjmedia/config.h
+++ b/pjmedia/include/pjmedia/config.h
@@ -541,47 +541,82 @@
 #endif
 
 
+/* 
+ * Below specifies the various tone generator backend algorithm.
+ */
+
+/** 
+ * The 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.
+ */
+#define PJMEDIA_TONEGEN_SINE			    1
+
 /**
- * Enable high quality of tone generation, the better quality will cost
- * more CPU load. This is only applied to floating point enabled machines.
+ * Floating point approximation of sine(). This has relatively good
+ * precision and much faster than plain sine(), but it requires floating-
+ * point support and linking with the math library.
+ */
+#define PJMEDIA_TONEGEN_FLOATING_POINT		    2
+
+/**
+ * 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 floating-point
+ * support.
+ */
+#define PJMEDIA_TONEGEN_FIXED_POINT_CORDIC	    3
+
+/**
+ * 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.
+ */
+#define PJMEDIA_TONEGEN_FAST_FIXED_POINT	    4
+
+
+/**
+ * Specify the tone generator algorithm to be used.
  *
- * By default it is enabled when PJ_HAS_FLOATING_POINT is set.
+ * Default value:
+ *  - PJMEDIA_TONEGEN_FLOATING_POINT when PJ_HAS_FLOATING_POINT is set
+ *  - PJMEDIA_TONEGEN_FIXED_POINT_CORDIC when PJ_HAS_FLOATING_POINT is not set
+ */
+#ifndef PJMEDIA_TONEGEN_ALG
+#   if defined(PJ_HAS_FLOATING_POINT) && PJ_HAS_FLOATING_POINT
+#	define PJMEDIA_TONEGEN_ALG	PJMEDIA_TONEGEN_FLOATING_POINT
+#   else
+#	define PJMEDIA_TONEGEN_ALG	PJMEDIA_TONEGEN_FIXED_POINT_CORDIC
+#   endif
+#endif
+
+
+/**
+ * Specify the number of calculation loops to generate the tone, when
+ * PJMEDIA_TONEGEN_FIXED_POINT_CORDIC algorithm is used. With more calculation
+ * loops, the tone signal gets more precise, but this will add more 
+ * processing.
+ *
+ * Valid values are 1 to 28.
  *
- * @see PJMEDIA_TONEGEN_FORCE_FLOAT
+ * Default value: 7
  */
-#ifndef PJMEDIA_USE_HIGH_QUALITY_TONEGEN
-#   define PJMEDIA_USE_HIGH_QUALITY_TONEGEN	    PJ_HAS_FLOATING_POINT
+#ifndef PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP
+#   define PJMEDIA_TONEGEN_FIXED_POINT_CORDIC_LOOP  7
 #endif
 
 
 /**
- * Force the tone generation to use floating point computation, even when
- * PJ_HAS_FLOATING_POINT is disabled. This may be necessary if the tone
- * generator is used to produce DTMF to be sent inband, since the fixed
- * point algorithm may not have the correct frequency accuracy.
+ * Enable high quality of tone generation, the better quality will cost
+ * more CPU load. This is only applied to floating point enabled machines.
  *
- * This option, combined with PJ_HAS_FLOATING_POINT will produce the 
- * following selection of tone generator algorithm:
- *  - if both PJ_HAS_FLOATING_POINT and PJMEDIA_USE_HIGH_QUALITY_TONEGEN 
- *    are set, the standard sin() function will be used. This will produce
- *    the highest quality tones, at the expense of more processing power.
- *  - if PJ_HAS_FLOATING_POINT is not set:
- *	- if both PJMEDIA_USE_HIGH_QUALITY_TONEGEN and 
- *        PJMEDIA_TONEGEN_FORCE_FLOAT are set, sin() based algorithm will
- *        be used (similar as above).
- *      - if PJMEDIA_USE_HIGH_QUALITY_TONEGEN is not set but the
- *        PJMEDIA_TONEGEN_FORCE_FLOAT is set, a floating point approximation
- *        algorithm will be used. This should produce good enough tone
- *        for most uses, and the performance is faster than using pure
- *        sin() based algorithm. Note that linking to math library may
- *        still be needed.
- *      - if both are not set, the fixed point approximation algorithm
- *        will be used.
+ * By default it is enabled when PJ_HAS_FLOATING_POINT is set.
  *
- * Default: 1
+ * This macro has been deprecated in version 1.0-rc3.
  */
-#ifndef PJMEDIA_TONEGEN_FORCE_FLOAT
-#   define PJMEDIA_TONEGEN_FORCE_FLOAT		    1
+#ifdef PJMEDIA_USE_HIGH_QUALITY_TONEGEN
+#   error   "The PJMEDIA_USE_HIGH_QUALITY_TONEGEN macro is obsolete"
 #endif