For pass through DTMF tones, measure the actual duration between the begin and end packets on the wire. If it is detected to be less than AST_MIN_DTMF_DURATION, trigger dtmf emulation.

AST-362


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@277247 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/channel.c

@@ -2406,6 +2406,19 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 					ast_clear_flag(chan, AST_FLAG_IN_DTMF);
 					if (!f->len)
 						f->len = ast_tvdiff_ms(now, chan->dtmf_tv);
+
+					/* detect tones that were received on
+					 * the wire with durations shorter than
+					 * AST_MIN_DTMF_DURATION and set f->len
+					 * to the actual duration of the DTMF
+					 * frames on the wire.  This will cause
+					 * dtmf emulation to be triggered later
+					 * on.
+					 */
+					if (ast_tvdiff_ms(now, chan->dtmf_tv) < AST_MIN_DTMF_DURATION) {
+						f->len = ast_tvdiff_ms(now, chan->dtmf_tv);
+						ast_log(LOG_DTMF, "DTMF end '%c' detected to have actual duration %ld on the wire, emulation will be triggered on %s\n", f->subclass, f->len, chan->name);
+					}
 				} else if (!f->len) {
 					ast_log(LOG_DTMF, "DTMF end accepted without begin '%c' on %s\n", f->subclass, chan->name);
 					f->len = AST_MIN_DTMF_DURATION;