3 * Copyright (C) 2008 Collabora Limited
4 * Copyright (C) 2008 Nokia Corporation
5 * Contact: Youness Alaoui <youness.alaoui@collabora.co.uk>
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
23 * SECTION:element-rtpdtmfdepay
24 * @short_description: Transforms RFC 4733/2833 RTP dtmf packets into sound
25 * @see_also: rtpdtmfsrc, rtpdtmfmux
27 * This element takes RTP DTMF packets and produces sound. It also emits a
28 * message on the #GstBus.
30 * The message is called "dtmf-event" and has the following fields
33 * <colspec colname='Name' />
34 * <colspec colname='Type' />
35 * <colspec colname='Possible values' />
36 * <colspec colname='Purpose' />
40 * <entry>GType</entry>
41 * <entry>Possible values</entry>
42 * <entry>Purpose</entry>
48 * <entry>G_TYPE_INT</entry>
50 * <entry>Which of the two methods
51 * specified in RFC 2833 to use. The value should be 0 for tones and 1 for
52 * named events. Tones are specified by their frequencies and events are specied
53 * by their number. This element currently only recognizes events.
54 * Do not confuse with "method" which specified the output.
58 * <entry>number</entry>
59 * <entry>G_TYPE_INT</entry>
61 * <entry>The event number.</entry>
64 * <entry>volume</entry>
65 * <entry>G_TYPE_INT</entry>
67 * <entry>This field describes the power level of the tone, expressed in dBm0
68 * after dropping the sign. Power levels range from 0 to -63 dBm0. The range of
69 * valid DTMF is from 0 to -36 dBm0.
73 * <entry>method</entry>
74 * <entry>G_TYPE_INT</entry>
76 * <entry>This field will always been 1 (ie RTP event) from this element.
91 #include <gst/rtp/gstrtpbuffer.h>
92 #include "gstrtpdtmfdepay.h"
95 # define M_PI 3.14159265358979323846 /* pi */
99 #define DEFAULT_PACKET_INTERVAL 50 /* ms */
100 #define MIN_PACKET_INTERVAL 10 /* ms */
101 #define MAX_PACKET_INTERVAL 50 /* ms */
102 #define SAMPLE_RATE 8000
103 #define SAMPLE_SIZE 16
108 #define MAX_VOLUME 36
109 #define MIN_INTER_DIGIT_INTERVAL 100
110 #define MIN_PULSE_DURATION 250
111 #define MIN_DUTY_CYCLE (MIN_INTER_DIGIT_INTERVAL + MIN_PULSE_DURATION)
113 #define MIN_UNIT_TIME 0
114 #define MAX_UNIT_TIME 1000
115 #define DEFAULT_UNIT_TIME 0
117 #define DEFAULT_MAX_DURATION 0
119 typedef struct st_dtmf_key
124 float high_frequency;
127 static const DTMF_KEY DTMF_KEYS[] = {
128 {"DTMF_KEY_EVENT_0", 0, 941, 1336},
129 {"DTMF_KEY_EVENT_1", 1, 697, 1209},
130 {"DTMF_KEY_EVENT_2", 2, 697, 1336},
131 {"DTMF_KEY_EVENT_3", 3, 697, 1477},
132 {"DTMF_KEY_EVENT_4", 4, 770, 1209},
133 {"DTMF_KEY_EVENT_5", 5, 770, 1336},
134 {"DTMF_KEY_EVENT_6", 6, 770, 1477},
135 {"DTMF_KEY_EVENT_7", 7, 852, 1209},
136 {"DTMF_KEY_EVENT_8", 8, 852, 1336},
137 {"DTMF_KEY_EVENT_9", 9, 852, 1477},
138 {"DTMF_KEY_EVENT_S", 10, 941, 1209},
139 {"DTMF_KEY_EVENT_P", 11, 941, 1477},
140 {"DTMF_KEY_EVENT_A", 12, 697, 1633},
141 {"DTMF_KEY_EVENT_B", 13, 770, 1633},
142 {"DTMF_KEY_EVENT_C", 14, 852, 1633},
143 {"DTMF_KEY_EVENT_D", 15, 941, 1633},
146 #define MAX_DTMF_EVENTS 16
150 DTMF_KEY_EVENT_1 = 1,
151 DTMF_KEY_EVENT_2 = 2,
152 DTMF_KEY_EVENT_3 = 3,
153 DTMF_KEY_EVENT_4 = 4,
154 DTMF_KEY_EVENT_5 = 5,
155 DTMF_KEY_EVENT_6 = 6,
156 DTMF_KEY_EVENT_7 = 7,
157 DTMF_KEY_EVENT_8 = 8,
158 DTMF_KEY_EVENT_9 = 9,
159 DTMF_KEY_EVENT_0 = 0,
160 DTMF_KEY_EVENT_STAR = 10,
161 DTMF_KEY_EVENT_POUND = 11,
162 DTMF_KEY_EVENT_A = 12,
163 DTMF_KEY_EVENT_B = 13,
164 DTMF_KEY_EVENT_C = 14,
165 DTMF_KEY_EVENT_D = 15,
168 /* elementfactory information */
169 static const GstElementDetails gst_rtp_dtmfdepay_details =
170 GST_ELEMENT_DETAILS ("RTP DTMF packet depayloader",
171 "Codec/Depayloader/Network",
172 "Generates DTMF Sound from telephone-event RTP packets",
173 "Youness Alaoui <youness.alaoui@collabora.co.uk>");
175 GST_DEBUG_CATEGORY_STATIC (gst_rtp_dtmf_depay_debug);
176 #define GST_CAT_DEFAULT gst_rtp_dtmf_depay_debug
198 static GstStaticPadTemplate gst_rtp_dtmf_depay_src_template =
199 GST_STATIC_PAD_TEMPLATE ("src",
202 GST_STATIC_CAPS ("audio/x-raw-int, "
205 "endianness = (int) " G_STRINGIFY (G_BYTE_ORDER) ", "
206 "signed = (boolean) true, "
207 "rate = (int) [0, MAX], " "channels = (int) 1")
210 static GstStaticPadTemplate gst_rtp_dtmf_depay_sink_template =
211 GST_STATIC_PAD_TEMPLATE ("sink",
214 GST_STATIC_CAPS ("application/x-rtp, "
215 "media = (string) \"audio\", "
216 "payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ", "
217 "clock-rate = (int) [ 0, MAX ], "
218 "encoding-name = (string) \"TELEPHONE-EVENT\"")
221 GST_BOILERPLATE (GstRtpDTMFDepay, gst_rtp_dtmf_depay, GstBaseRTPDepayload,
222 GST_TYPE_BASE_RTP_DEPAYLOAD);
224 static void gst_rtp_dtmf_depay_set_property (GObject * object, guint prop_id,
225 const GValue * value, GParamSpec * pspec);
226 static void gst_rtp_dtmf_depay_get_property (GObject * object, guint prop_id,
227 GValue * value, GParamSpec * pspec);
228 static GstBuffer *gst_rtp_dtmf_depay_process (GstBaseRTPDepayload * depayload,
230 gboolean gst_rtp_dtmf_depay_setcaps (GstBaseRTPDepayload * filter,
234 gst_rtp_dtmf_depay_base_init (gpointer klass)
236 GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
238 gst_element_class_add_pad_template (element_class,
239 gst_static_pad_template_get (&gst_rtp_dtmf_depay_src_template));
240 gst_element_class_add_pad_template (element_class,
241 gst_static_pad_template_get (&gst_rtp_dtmf_depay_sink_template));
244 GST_DEBUG_CATEGORY_INIT (gst_rtp_dtmf_depay_debug,
245 "rtpdtmfdepay", 0, "rtpdtmfdepay element");
246 gst_element_class_set_details (element_class, &gst_rtp_dtmfdepay_details);
250 gst_rtp_dtmf_depay_class_init (GstRtpDTMFDepayClass * klass)
252 GObjectClass *gobject_class;
253 GstElementClass *gstelement_class;
254 GstBaseRTPDepayloadClass *gstbasertpdepayload_class;
256 gobject_class = (GObjectClass *) klass;
257 gstelement_class = (GstElementClass *) klass;
258 gstbasertpdepayload_class = (GstBaseRTPDepayloadClass *) klass;
260 parent_class = g_type_class_peek_parent (klass);
262 gobject_class->set_property =
263 GST_DEBUG_FUNCPTR (gst_rtp_dtmf_depay_set_property);
264 gobject_class->get_property =
265 GST_DEBUG_FUNCPTR (gst_rtp_dtmf_depay_get_property);
267 g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_UNIT_TIME,
268 g_param_spec_uint ("unit-time", "Duration unittime",
269 "The smallest unit (ms) the duration must be a multiple of (0 disables it)",
270 MIN_UNIT_TIME, MAX_UNIT_TIME, DEFAULT_UNIT_TIME, G_PARAM_READWRITE));
272 g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_MAX_DURATION,
273 g_param_spec_uint ("max-duration", "Maximum duration",
274 "The maxumimum duration (ms) of the outgoing soundpacket. "
275 "(0 = no limit)", 0, G_MAXUINT, DEFAULT_MAX_DURATION,
278 gstbasertpdepayload_class->process =
279 GST_DEBUG_FUNCPTR (gst_rtp_dtmf_depay_process);
280 gstbasertpdepayload_class->set_caps =
281 GST_DEBUG_FUNCPTR (gst_rtp_dtmf_depay_setcaps);
286 gst_rtp_dtmf_depay_init (GstRtpDTMFDepay * rtpdtmfdepay,
287 GstRtpDTMFDepayClass * klass)
289 rtpdtmfdepay->unit_time = DEFAULT_UNIT_TIME;
293 gst_rtp_dtmf_depay_set_property (GObject * object, guint prop_id,
294 const GValue * value, GParamSpec * pspec)
296 GstRtpDTMFDepay *rtpdtmfdepay;
298 rtpdtmfdepay = GST_RTP_DTMF_DEPAY (object);
302 rtpdtmfdepay->unit_time = g_value_get_uint (value);
304 case PROP_MAX_DURATION:
305 rtpdtmfdepay->max_duration = g_value_get_uint (value);
308 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
314 gst_rtp_dtmf_depay_get_property (GObject * object, guint prop_id,
315 GValue * value, GParamSpec * pspec)
317 GstRtpDTMFDepay *rtpdtmfdepay;
319 rtpdtmfdepay = GST_RTP_DTMF_DEPAY (object);
323 g_value_set_uint (value, rtpdtmfdepay->unit_time);
325 case PROP_MAX_DURATION:
326 g_value_set_uint (value, rtpdtmfdepay->max_duration);
329 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
335 gst_rtp_dtmf_depay_setcaps (GstBaseRTPDepayload * filter, GstCaps * caps)
338 GstStructure *structure = gst_caps_get_structure (caps, 0);
339 gint clock_rate = 8000; /* default */
341 gst_structure_get_int (structure, "clock-rate", &clock_rate);
342 filter->clock_rate = clock_rate;
344 srccaps = gst_caps_new_simple ("audio/x-raw-int",
345 "width", G_TYPE_INT, 16,
346 "depth", G_TYPE_INT, 16,
347 "endianness", G_TYPE_INT, G_BYTE_ORDER,
348 "signed", G_TYPE_BOOLEAN, TRUE,
349 "channels", G_TYPE_INT, 1, "rate", G_TYPE_INT, clock_rate, NULL);
350 gst_pad_set_caps (GST_BASE_RTP_DEPAYLOAD_SRCPAD (filter), srccaps);
351 gst_caps_unref (srccaps);
357 gst_dtmf_src_generate_tone (GstRtpDTMFDepay * rtpdtmfdepay,
358 GstRTPDTMFPayload payload, GstBuffer * buffer)
363 double amplitude, f1, f2;
364 double volume_factor;
365 DTMF_KEY key = DTMF_KEYS[payload.event];
366 guint32 clock_rate = 8000 /* default */ ;
367 GstBaseRTPDepayload *depayload = GST_BASE_RTP_DEPAYLOAD (rtpdtmfdepay);
370 clock_rate = depayload->clock_rate;
372 /* Create a buffer for the tone */
373 tone_size = (payload.duration * SAMPLE_SIZE * CHANNELS) / 8;
374 GST_BUFFER_SIZE (buffer) = tone_size;
375 GST_BUFFER_MALLOCDATA (buffer) = g_malloc (tone_size);
376 GST_BUFFER_DATA (buffer) = GST_BUFFER_MALLOCDATA (buffer);
377 GST_BUFFER_DURATION (buffer) = payload.duration * GST_SECOND / clock_rate;
378 volume = payload.volume;
380 p = (gint16 *) GST_BUFFER_MALLOCDATA (buffer);
382 volume_factor = pow (10, (-volume) / 20);
385 * For each sample point we calculate 'x' as the
386 * the amplitude value.
388 for (i = 0; i < (tone_size / (SAMPLE_SIZE / 8)); i++) {
390 * We add the fundamental frequencies together.
392 f1 = sin (2 * M_PI * key.low_frequency * (rtpdtmfdepay->sample /
394 f2 = sin (2 * M_PI * key.high_frequency * (rtpdtmfdepay->sample /
397 amplitude = (f1 + f2) / 2;
399 /* Adjust the volume */
400 amplitude *= volume_factor;
402 /* Make the [-1:1] interval into a [-32767:32767] interval */
405 /* Store it in the data buffer */
406 *(p++) = (gint16) amplitude;
408 (rtpdtmfdepay->sample)++;
414 gst_rtp_dtmf_depay_process (GstBaseRTPDepayload * depayload, GstBuffer * buf)
417 GstRtpDTMFDepay *rtpdtmfdepay = NULL;
418 GstBuffer *outbuf = NULL;
420 guint8 *payload = NULL;
422 GstRTPDTMFPayload dtmf_payload;
424 GstStructure *structure = NULL;
425 GstMessage *dtmf_message = NULL;
427 rtpdtmfdepay = GST_RTP_DTMF_DEPAY (depayload);
429 if (!gst_rtp_buffer_validate (buf))
432 payload_len = gst_rtp_buffer_get_payload_len (buf);
433 payload = gst_rtp_buffer_get_payload (buf);
435 if (payload_len != sizeof (GstRTPDTMFPayload))
438 memcpy (&dtmf_payload, payload, sizeof (GstRTPDTMFPayload));
440 if (dtmf_payload.event > MAX_EVENT)
444 marker = gst_rtp_buffer_get_marker (buf);
446 timestamp = gst_rtp_buffer_get_timestamp (buf);
448 dtmf_payload.duration = g_ntohs (dtmf_payload.duration);
450 /* clip to whole units of unit_time */
451 if (rtpdtmfdepay->unit_time) {
452 guint unit_time_clock =
453 (rtpdtmfdepay->unit_time * depayload->clock_rate) / 1000;
454 if (dtmf_payload.duration % unit_time_clock) {
455 /* Make sure we don't overflow the duration */
456 if (dtmf_payload.duration < G_MAXUINT16 - unit_time_clock)
457 dtmf_payload.duration += unit_time_clock -
458 (dtmf_payload.duration % unit_time_clock);
460 dtmf_payload.duration -= dtmf_payload.duration % unit_time_clock;
464 /* clip to max duration */
465 if (rtpdtmfdepay->max_duration) {
466 guint max_duration_clock =
467 (rtpdtmfdepay->max_duration * depayload->clock_rate) / 1000;
469 if (max_duration_clock < G_MAXUINT16 &&
470 dtmf_payload.duration > max_duration_clock)
471 dtmf_payload.duration = max_duration_clock;
474 GST_DEBUG_OBJECT (depayload, "Received new RTP DTMF packet : "
475 "marker=%d - timestamp=%u - event=%d - duration=%d",
476 marker, timestamp, dtmf_payload.event, dtmf_payload.duration);
478 GST_DEBUG_OBJECT (depayload,
479 "Previous information : timestamp=%u - duration=%d",
480 rtpdtmfdepay->previous_ts, rtpdtmfdepay->previous_duration);
483 if (marker || rtpdtmfdepay->previous_ts != timestamp) {
484 rtpdtmfdepay->sample = 0;
485 rtpdtmfdepay->previous_ts = timestamp;
486 rtpdtmfdepay->previous_duration = dtmf_payload.duration;
487 rtpdtmfdepay->first_gst_ts = GST_BUFFER_TIMESTAMP (buf);
489 structure = gst_structure_new ("dtmf-event",
490 "number", G_TYPE_INT, dtmf_payload.event,
491 "volume", G_TYPE_INT, dtmf_payload.volume,
492 "type", G_TYPE_INT, 1, "method", G_TYPE_INT, 1, NULL);
495 gst_message_new_element (GST_OBJECT (depayload), structure);
497 if (!gst_element_post_message (GST_ELEMENT (depayload), dtmf_message)) {
498 GST_ERROR_OBJECT (depayload,
499 "Unable to send dtmf-event message to bus");
502 GST_ERROR_OBJECT (depayload, "Unable to create dtmf-event message");
505 GST_ERROR_OBJECT (depayload, "Unable to create dtmf-event structure");
508 guint16 duration = dtmf_payload.duration;
509 dtmf_payload.duration -= rtpdtmfdepay->previous_duration;
510 /* If late buffer, ignore */
511 if (duration > rtpdtmfdepay->previous_duration)
512 rtpdtmfdepay->previous_duration = duration;
515 GST_DEBUG_OBJECT (depayload, "new previous duration : %d - new duration : %d"
516 " - diff : %d - clock rate : %d - timestamp : %llu",
517 rtpdtmfdepay->previous_duration, dtmf_payload.duration,
518 (rtpdtmfdepay->previous_duration - dtmf_payload.duration),
519 depayload->clock_rate, GST_BUFFER_TIMESTAMP (buf));
521 /* If late or duplicate packet (like the redundant end packet). Ignore */
522 if (dtmf_payload.duration > 0) {
523 outbuf = gst_buffer_new ();
524 gst_dtmf_src_generate_tone (rtpdtmfdepay, dtmf_payload, outbuf);
527 GST_BUFFER_TIMESTAMP (outbuf) = rtpdtmfdepay->first_gst_ts +
528 (rtpdtmfdepay->previous_duration - dtmf_payload.duration) *
529 GST_SECOND / depayload->clock_rate;
530 GST_BUFFER_OFFSET (outbuf) =
531 (rtpdtmfdepay->previous_duration - dtmf_payload.duration) *
532 GST_SECOND / depayload->clock_rate;
533 GST_BUFFER_OFFSET_END (outbuf) = rtpdtmfdepay->previous_duration *
534 GST_SECOND / depayload->clock_rate;
536 GST_DEBUG_OBJECT (depayload, "timestamp : %llu - time %" GST_TIME_FORMAT,
537 GST_BUFFER_TIMESTAMP (buf), GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)));
545 GST_ELEMENT_WARNING (rtpdtmfdepay, STREAM, DECODE,
546 ("Packet did not validate"), (NULL));
551 gst_rtp_dtmf_depay_plugin_init (GstPlugin * plugin)
553 return gst_element_register (plugin, "rtpdtmfdepay",
554 GST_RANK_MARGINAL, GST_TYPE_RTP_DTMF_DEPAY);