add new channel cap flag to indicate you can support queueable dtmf delay aka parsing w and W and implement it in the RTP stack and sofia endpoint

src/include/switch_types.h

@@ -1087,6 +1087,7 @@ typedef enum {
 	CC_PROXY_MEDIA,
 	CC_JITTERBUFFER,
 	CC_FS_RTP,
+	CC_QUEUEABLE_DTMF_DELAY,
 	/* WARNING: DO NOT ADD ANY FLAGS BELOW THIS LINE */
 	CC_FLAG_MAX
 } switch_channel_cap_t;

src/mod/endpoints/mod_sofia/sofia_glue.c

@@ -876,6 +876,7 @@ void sofia_glue_attach_private(switch_core_session_t *session, sofia_profile_t *
 	switch_channel_set_cap(tech_pvt->channel, CC_PROXY_MEDIA);
 	switch_channel_set_cap(tech_pvt->channel, CC_JITTERBUFFER);
 	switch_channel_set_cap(tech_pvt->channel, CC_FS_RTP);
+	switch_channel_set_cap(tech_pvt->channel, CC_QUEUEABLE_DTMF_DELAY);
 
 	switch_core_session_set_private(session, tech_pvt);
 

src/switch_core_io.c

@@ -1345,11 +1345,22 @@ SWITCH_DECLARE(switch_status_t) switch_core_session_send_dtmf(switch_core_sessio
 	}
 
 	if (session->endpoint_interface->io_routines->send_dtmf) {
+		int send = 0;
+		status = SWITCH_STATUS_SUCCESS;
+		
+		if (switch_channel_test_cap(session->channel, CC_QUEUEABLE_DTMF_DELAY) && (dtmf->digit == 'w' || dtmf->digit == 'W')) {
+			send = 1;
+		} else {
 			if (dtmf->digit == 'w') {
 				switch_yield(500000);
 			} else if (dtmf->digit == 'W') {
 				switch_yield(1000000);
 			} else {
+				send = 1;
+			}
+		}
+
+		if (send) {
 			status = session->endpoint_interface->io_routines->send_dtmf(session, &new_dtmf);
 		}
 	}

src/switch_rtp.c

@@ -2233,6 +2233,21 @@ SWITCH_DECLARE(void) switch_rtp_clear_flag(switch_rtp_t *rtp_session, switch_rtp
 	}
 }
 
+static void set_dtmf_delay(switch_rtp_t *rtp_session, uint32_t ms)
+{
+	int mspp = 20;
+
+	if (rtp_session->ms_per_packet) {
+		if (!(mspp = (int) (rtp_session->ms_per_packet / 1000))) {
+			mspp = 20;
+		}
+	}
+	
+	rtp_session->dtmf_data.out_digit_delay += (ms / mspp);
+	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Queue digit delay of %dms\n", ms);
+	
+}
+
 static void do_2833(switch_rtp_t *rtp_session, switch_core_session_t *session)
 {
 	switch_frame_flag_t flags = 0;
@@ -2310,6 +2325,19 @@ static void do_2833(switch_rtp_t *rtp_session, switch_core_session_t *session)
 			switch_dtmf_t *rdigit = pop;
 			int64_t offset;
 			switch_size_t wrote;
+
+			if (rdigit->digit == 'w') {
+				set_dtmf_delay(rtp_session, 500);
+				free(rdigit);
+				return;
+			}
+
+			if (rdigit->digit == 'W') {
+				set_dtmf_delay(rtp_session, 1000);
+				free(rdigit);
+				return;
+			}
+			
 			rtp_session->sending_dtmf = 1;
 
 			memset(rtp_session->dtmf_data.out_digit_packet, 0, 4);