Fixed fxotune utility. It now can automatically find the best impedance and

other values for the line.  If you are having problems with echo on your
FXO modules, take a look at this utility.  It should fix most of your echo
issues.


git-svn-id: http://svn.digium.com/svn/zaptel/trunk@594 5390a7c7-147a-4af0-8ec9-7488f05a26cb

1 files changed, 31 insertions, 20 deletions

diff --git a/fxotune.c b/fxotune.c
index 8560e75..2726e13 100755
--- a/fxotune.c
+++ b/fxotune.c
@@ -50,18 +50,6 @@ static short outbuf[TEST_DURATION];
 static int debug = 0;
 
 
-#if 0
-int process_readbuf(short *ibuf)
-{
-	int sum=0;
-	int x;
-	for (x=0;x<BUFFER_LENGTH;x++) {
-		sum += abs(ibuf[x]);
-	}
-	return sum;
-}
-#endif
-
 /* Generates a tone of hz frequency.  Index is the current sample
  * to begenerated.  For a normal waveform you need to increment
  * this every time you execute the function.
@@ -96,8 +84,16 @@ static float power_of(void *prebuf, int bufsize, int short_format)
 		numsamples = bufsize / 2;
 
 		for (i = 0; i < numsamples; i++) {
+#if 0
 			sum_of_squares += ((float)sbuf[i] * (float)sbuf[i])/(float)32768;
-			square_of_sums += (float)sbuf[i]/(float)32768;
+#endif
+			sum_of_squares += ((float)sbuf[i] * (float)sbuf[i]);
+			if (sbuf[i] > 0) {
+				square_of_sums += (float)sbuf[i];
+			} else {
+				sbuf[i] *= -1;
+				square_of_sums += (float)sbuf[i];
+			}
 		}
 	} else {
 		/* Version for float inputs */
@@ -107,12 +103,23 @@ static float power_of(void *prebuf, int bufsize, int short_format)
 		}
 	}
 
+	if (debug) printf("sum_of_squares = %f\n", sum_of_squares);
+
 	square_of_sums *= square_of_sums; /* sums ^ 2 */
 
-	finalanswer = sum_of_squares - square_of_sums;
+	if (debug) printf("square_of_sums = %f\n", square_of_sums);
+
+	finalanswer = square_of_sums - sum_of_squares; 
+
+	if (debug) printf("finalanswer = %f\n", finalanswer);
 
-	if (finalanswer < 0)
+	if (finalanswer < 0) {
+		printf("Error: Final answer negative number %f\n", finalanswer);
 		return -3;
+	}
+#if 0
+		finalanswer = finalanswer * (float)-1;
+#endif
 
 	return sqrtf(finalanswer);
 }
@@ -407,14 +414,15 @@ static int acim_tune(int whichzap, char *dialstr)
 			/* calculate power of response */
 			
 			freq_results[(freq/200)-1] = power_of(inbuf+SKIP_BYTES, BUFFER_LENGTH-SKIP_BYTES, 1);
-			fprintf(outfile, "%d,%d,%f\n", i, freq, freq_results[(freq/200)-1]);
+			if (debug) fprintf(outfile, "%d,%d,%f\n", acim, freq, freq_results[(freq/200)-1]);
 		}
-		
-		acim_results[i] = power_of(freq_results, 15, 0);
+		acim_results[acim] = power_of(freq_results, 15, 0);
 	}
 
+	for (i = 0; i < 16; i++)
+		fprintf(outfile, "acim_results[%d] = %f\n", i, acim_results[i]);
 	/* Find out what the "best" impedance is for the line */
-	lowest = 1;
+	lowest = 0;
 	for (i = 0; i < 16; i++) {
 		if (acim_results[i] < acim_results[lowest]) {
 			lowest = i;
@@ -431,6 +439,7 @@ int main (int argc , char **argv)
 	int fd;
 	int res = 0;
 	int configfd;
+	FILE *fp = NULL;
 
 	if ((argc < 2) || (argc > 3)) {
 		/* Show usage */
@@ -439,7 +448,7 @@ int main (int argc , char **argv)
 	}
 
 	if (!strcasecmp(argv[1], "-s")) {
-		FILE *fp = NULL;
+set:
 
 		fp = fopen(configfile, "r");
 
@@ -548,6 +557,8 @@ int main (int argc , char **argv)
 		}
 
 		close(configfd);
+		/* Some getto goto hackery to make this more convenient */
+		goto set;
 	}
 
 	return 0;