rtpengine/daemon/dtmf.c

#include "dtmf.h"
#include "media_socket.h"
#include "log.h"
#include "call.h"
#include "dtmflib.h"



static GString *dtmf_json_print(struct media_packet *mp,
		struct telephone_event_payload *dtmf, int clockrate)
{
	if (!dtmf->end)
		return NULL;

	GString *buf = g_string_new("");

	if (!clockrate)
		clockrate = 8000;

	g_string_append_printf(buf, "{"
			"\"callid\":\"" STR_FORMAT "\","
			"\"source_tag\":\"" STR_FORMAT "\","
			"\"tags\":[",
			STR_FMT(&mp->call->callid),
			STR_FMT(&mp->media->monologue->tag));

	GList *tag_values = g_hash_table_get_values(mp->call->tags);
	int i = 0;
	for (GList *tag_it = tag_values; tag_it; tag_it = tag_it->next) {
		struct call_monologue *ml = tag_it->data;
		if (i != 0)
			g_string_append(buf, ",");
		g_string_append_printf(buf, "\"" STR_FORMAT "\"",
				STR_FMT(&ml->tag));
		i++;
	}
	g_list_free(tag_values);

	g_string_append_printf(buf, "],"
			"\"type\":\"DTMF\",\"timestamp\":%lu,\"source_ip\":\"%s\","
			"\"event\":%u,\"duration\":%u,\"volume\":%u}",
			(unsigned long) rtpe_now.tv_sec,
			sockaddr_print_buf(&mp->fsin.address),
			(unsigned int) dtmf->event,
			(ntohs(dtmf->duration) * (1000000 / clockrate)) / 1000,
			(unsigned int) dtmf->volume);

	return buf;
}

int dtmf_event(struct media_packet *mp, str *payload, int clockrate) {
	struct telephone_event_payload *dtmf;
	if (payload->len < sizeof(*dtmf)) {
		ilog(LOG_WARN | LOG_FLAG_LIMIT, "Short DTMF event packet (len %u)", payload->len);
		return -1;
	}
	dtmf = (void *) payload->s;

	ilog(LOG_DEBUG, "DTMF event: event %u, volume %u, end %u, duration %u",
			dtmf->event, dtmf->volume, dtmf->end, dtmf->duration);

	int ret = 0;

	if (_log_facility_dtmf) {
		GString *buf = dtmf_json_print(mp, dtmf, clockrate);
		if (buf) {
			dtmflog(buf);
			ret = 1; // END event
		}
	}

	return ret;
}

void dtmf_event_free(void *e) {
	g_slice_free1(sizeof(struct dtmf_event), e);
}

// returns: 0 = no DTMF. 1 = DTMF start event. 2 = DTMF in progress. 3 = DTMF end event.
int dtmf_event_payload(str *buf, uint64_t *pts, uint64_t duration, struct dtmf_event *cur_event, GQueue *events) {
	// do we have a relevant state change?
	struct dtmf_event prev_event = *cur_event;
	while (events->length) {
		struct dtmf_event *ev = g_queue_peek_head(events);
		ilog(LOG_DEBUG, "Next DTMF event starts at %lu. PTS now %li", (unsigned long) ev->ts,
				(unsigned long) *pts);
		if (ev->ts > *pts)
			break; // future event

		ilog(LOG_DEBUG, "DTMF state change at %lu: %i -> %i, duration %lu", (unsigned long) ev->ts,
				cur_event->code, ev->code, (unsigned long) duration);
		g_queue_pop_head(events);
		*cur_event = *ev;
		dtmf_event_free(ev);
		cur_event->ts = *pts; // canonicalise start TS
	}

	int ret = 2; // normal: in progress
	if (cur_event->code == 0) {
		if (prev_event.code == 0)
			return 0;
		// state change from DTMF back to audio. send DTMF end code.
		ret = 3;
		cur_event = &prev_event;
	}
	else if (prev_event.code == 0)
		ret = 1; // start event

	int dtmf_code = -1;
	if (cur_event->code >= '0' && cur_event->code <= '9')
		dtmf_code = cur_event->code - '0';
	else if (cur_event->code == '*')
		dtmf_code = 10;
	else if (cur_event->code == '#')
		dtmf_code = 11;
	else if (cur_event->code >= 'A' && cur_event->code <= 'D')
		dtmf_code = cur_event->code - 'A' + 12;
	else {
		ilog(LOG_ERR | LOG_FLAG_LIMIT, "Unknown DTMF event code %i", cur_event->code);
		return 0;
	}

	// replace audio RTP frame with DTMF payload
	struct telephone_event_payload *ev_pt = (void *) buf->s;
	buf->len = sizeof(*ev_pt);
	ZERO(*ev_pt);

	ev_pt->event = dtmf_code;
	if (cur_event->volume > 0)
		ev_pt->volume = 0;
	else if (cur_event->volume >= -63)
		ev_pt->volume = -1 * cur_event->volume;
	else
		ev_pt->volume = 63;
	ev_pt->end = (ret == 3) ? 1 : 0;
	ev_pt->duration = htons(*pts - cur_event->ts + duration);

	// fix up timestamp
	*pts = cur_event->ts;

	return ret;
}