From fd04da511461f1d21b4166a9937e3f00696de20d Mon Sep 17 00:00:00 2001
From: Jonathan Rose <jrose@digium.com>
Date: Thu, 5 Jan 2012 22:02:33 +0000
Subject: [PATCH] Fix an issue where dsp.c would interpret multiple dtmf events
from a single key press.
When receiving calls from a mobile phone into a DISA system on a connection with
significant interference, the reporter's Asterisk system would interpret DTMF incorrectly
and replicate digits received. This patch resolves that by increasing the number of
frames a mismatch has to be detected before assuming the DTMF is over by 1 frame and
adjusts dtmf_detect function to reset hits and misses only when an edge is detected.
(closes issue ASTERISK-17493)
Reported by: Alec Davis
Patches:
bug18904-refactor.diff.txt uploaded by Alec Davis (license 5546)
Review: https://reviewboard.asterisk.org/r/1130/
........
Merged revisions 349728 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........
Merged revisions 349729 from http://svn.asterisk.org/svn/asterisk/branches/10
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@349730 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
main/dsp.c | 63 +++++++++++++++++++++++++++---------------------------
1 file changed, 31 insertions(+), 32 deletions(-)
diff --git a/main/dsp.c b/main/dsp.c
index 0f8955314f..ec25f96c67 100644
--- a/main/dsp.c
+++ b/main/dsp.c
@@ -201,9 +201,9 @@ enum gsamp_thresh {
#define DTMF_GSIZE 102
/* How many successive hits needed to consider begin of a digit */
-#define DTMF_HITS_TO_BEGIN 2
+#define DTMF_HITS_TO_BEGIN 4
/* How many successive misses needed to consider end of a digit */
-#define DTMF_MISSES_TO_END 3
+#define DTMF_MISSES_TO_END 4
/*!
* \brief The default silence threshold we will use if an alternate
@@ -721,42 +721,41 @@ static int dtmf_detect(struct ast_dsp *dsp, digit_detect_state_t *s, int16_t amp
}
}
- if (s->td.dtmf.current_hit) {
- /* We are in the middle of a digit already */
- if (hit != s->td.dtmf.current_hit) {
- s->td.dtmf.misses++;
- if (s->td.dtmf.misses == s->td.dtmf.misses_to_end) {
- /* There were enough misses to consider digit ended */
- s->td.dtmf.current_hit = 0;
+ if (hit == s->td.dtmf.lasthit) {
+ if (s->td.dtmf.current_hit) {
+ /* We are in the middle of a digit already */
+ if (hit) {
+ if (hit != s->td.dtmf.current_hit) {
+ /* Look for a start of a new digit.
+ This is because hits_to_begin may be smaller than misses_to_end
+ and we may find the beginning of new digit before we consider last one ended. */
+ s->td.dtmf.current_hit = 0;
+ } else {
+ /* Current hit was same as last, so increment digit duration (of last digit) */
+ s->digitlen[s->current_digits - 1] += DTMF_GSIZE;
+ }
+ } else {
+ /* No Digit */
+ s->td.dtmf.misses++;
+ if (s->td.dtmf.misses == s->td.dtmf.misses_to_end) {
+ /* There were enough misses to consider digit ended */
+ s->td.dtmf.current_hit = 0;
+ }
}
- } else {
- s->td.dtmf.misses = 0;
- /* Current hit was same as last, so increment digit duration (of last digit) */
- s->digitlen[s->current_digits - 1] += DTMF_GSIZE;
- }
- }
-
- /* Look for a start of a new digit no matter if we are already in the middle of some
- digit or not. This is because hits_to_begin may be smaller than misses_to_end
- and we may find begin of new digit before we consider last one ended. */
- if (hit) {
- if (hit == s->td.dtmf.lasthit) {
+ } else if (hit) {
+ /* Detecting new digit */
s->td.dtmf.hits++;
- } else {
- s->td.dtmf.hits = 1;
- }
-
- if (s->td.dtmf.hits == s->td.dtmf.hits_to_begin && hit != s->td.dtmf.current_hit) {
- store_digit(s, hit);
- s->td.dtmf.current_hit = hit;
- s->td.dtmf.misses = 0;
+ if (s->td.dtmf.hits == s->td.dtmf.hits_to_begin) {
+ store_digit(s, hit);
+ s->td.dtmf.current_hit = hit;
+ }
}
} else {
- s->td.dtmf.hits = 0;
+ s->td.dtmf.hits = 1;
+ s->td.dtmf.misses = 1;
+ s->td.dtmf.lasthit = hit;
}
- s->td.dtmf.lasthit = hit;
-
/* If we had a hit in this block, include it into mute fragment */
if (squelch && hit) {
if (mute.end < sample - DTMF_GSIZE) {
--
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