[svn-commits] kpfleming: branch linux/kpfleming/echocan_work r6441 - /linux/team/kpfleming/...

[SVN commits to the Digium repositories]

Author: kpfleming
Date: Tue Apr 21 19:35:53 2009
New Revision: 6441

URL: http://svn.digium.com/svn-view/dahdi?view=rev&rev=6441
Log:
(yes, i reindented this code... sue me <G>)

make the CED detector work in more cases, especially for FAX machines that generate CED/ANS without polarity reversals


Modified:
    linux/team/kpfleming/echocan_work/drivers/dahdi/ecdis.h

Modified: linux/team/kpfleming/echocan_work/drivers/dahdi/ecdis.h
URL: http://svn.digium.com/svn-view/dahdi/linux/team/kpfleming/echocan_work/drivers/dahdi/ecdis.h?view=diff&rev=6441&r1=6440&r2=6441
==============================================================================
--- linux/team/kpfleming/echocan_work/drivers/dahdi/ecdis.h (original)
+++ linux/team/kpfleming/echocan_work/drivers/dahdi/ecdis.h Tue Apr 21 19:35:53 2009
@@ -53,10 +53,10 @@
 /*- End of function --------------------------------------------------------*/
 
 static inline int echo_can_disable_detector_update (echo_can_disable_detector_state_t *det,
-                                      int16_t amp)
+						    int16_t amp)
 {
-    int16_t notched;
-    
+	int16_t notched;
+	
     	notched = biquad2 (&det->notch, amp);
     	/* Estimate the overall energy in the channel, and the energy in
 	   the notch (i.e. overall channel energy - tone energy => noise).
@@ -66,40 +66,38 @@
 	   blip every time the phase reverses */
         det->channel_level += ((abs(amp) - det->channel_level) >> 5);
 	det->notch_level += ((abs(notched) - det->notch_level) >> 4);
-  	if (det->channel_level >= 70)
-	{
-	    /* There is adequate energy in the channel. Is it mostly at 2100Hz? */
-	    if (det->notch_level*6 < det->channel_level)
-	    {
-                /* The notch says yes, so we have the tone. */
-		if (!det->tone_present)
-		{
-                    /* Do we get a kick every 450+-25ms? */
-		    if (det->tone_cycle_duration >= 425*8
-			&&
-			det->tone_cycle_duration <= 475*8)
-	            {
-			det->good_cycles++;
-			if (det->good_cycles > 2)
-			    det->hit = TRUE;
-		    }
-		    det->tone_cycle_duration = 0;
+  	if (det->channel_level >= 70) {
+		/* There is adequate energy in the channel. Is it mostly at 2100Hz? */
+		if (det->notch_level*6 < det->channel_level) {
+			det->tone_cycle_duration++;
+			/* The notch says yes, so we have the tone. */
+			if (!det->tone_present) {
+				/* Do we get a kick every 450+-25ms? */
+				if ((det->tone_cycle_duration >= (425 * 8)) &&
+				    (det->tone_cycle_duration <= (475 * 8))) {
+					/* It's ANS/PR (CED with polarity reversals), so wait
+					   for at least three cycles before returning a hit. */
+					det->good_cycles++;
+					if (det->good_cycles > 2)
+						det->hit = TRUE;
+				}
+				det->tone_cycle_duration = 0;
+				det->tone_present = TRUE;
+			} else if (det->tone_cycle_duration >= 600 * 8) {
+				/* It's ANS (CED without polarity reversals)
+				   so return a hit. */
+				det->hit = TRUE;
+			}
+		} else {
+			det->tone_present = FALSE;
 		}
-		det->tone_present = TRUE;
-	    }
-	    else
-	    {
+	} else { 
 		det->tone_present = FALSE;
-	    }
-   	    det->tone_cycle_duration++;
+		det->tone_cycle_duration = 0;
+		det->good_cycles = 0;
 	}
-	else
-	{
-	    det->tone_present = FALSE;
-	    det->tone_cycle_duration = 0;
-	    det->good_cycles = 0;
-	}
-    return  det->hit;
+
+	return  det->hit;
 }
 /*- End of function --------------------------------------------------------*/
 /*- End of file ------------------------------------------------------------*/