RFC 2833 support!

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@215 74dad513-b988-da41-8d7b-12977e46ad98

9 files changed, 409 insertions, 53 deletions

diff --git a/pjmedia/include/pjmedia/errno.h b/pjmedia/include/pjmedia/errno.h
index 4fa26afd..accf3fd1 100644
--- a/pjmedia/include/pjmedia/errno.h
+++ b/pjmedia/include/pjmedia/errno.h
@@ -293,6 +293,16 @@ PJ_BEGIN_DECL
  * Invalid media type.
  */
 #define PJMEDIA_EINVALIMEDIATYPE    (PJMEDIA_ERRNO_START+104)    /* 220104 */
+/**
+ * @hideinitializer
+ * Remote does not support DTMF.
+ */
+#define PJMEDIA_EREMOTENODTMF	    (PJMEDIA_ERRNO_START+105)    /* 220105 */
+/**
+ * @hideinitializer
+ * Invalid DTMF digit.
+ */
+#define PJMEDIA_RTP_EINDTMF	    (PJMEDIA_ERRNO_START+106)    /* 220106 */
 
 
 
@@ -354,11 +364,6 @@ PJ_BEGIN_DECL
  * RTP is not configured.
  */
 #define PJMEDIA_RTP_ENOCONFIG	    (PJMEDIA_ERRNO_START+134)    /* 220134 */
-/**
- * @hideinitializer
- * Invalid DTMF digit.
- */
-#define PJMEDIA_RTP_EINDTMF	    (PJMEDIA_ERRNO_START+135)    /* 220135 */
 
 
 /************************************************************
diff --git a/pjmedia/include/pjmedia/session.h b/pjmedia/include/pjmedia/session.h
index 78d699ff..1335bd5f 100644
--- a/pjmedia/include/pjmedia/session.h
+++ b/pjmedia/include/pjmedia/session.h
@@ -80,6 +80,7 @@ struct pjmedia_session_info
  *			created in the session.
  * @param local_sdp	The SDP describing local capability.
  * @param rem_sdp	The SDP describing remote capability.
+ * @param user_data	Arbitrary user data to be kept in the session.
  * @param p_session	Pointer to receive the media session.
  *
  * @return		PJ_SUCCESS if media session can be created 
@@ -91,6 +92,7 @@ pjmedia_session_create( pjmedia_endpt *endpt,
 			const pjmedia_sock_info skinfo[],
 			const pjmedia_sdp_session *local_sdp,
 			const pjmedia_sdp_session *rem_sdp,
+			void *user_data,
 			pjmedia_session **p_session );
 
 
@@ -197,6 +199,51 @@ PJ_DECL(pj_status_t) pjmedia_session_get_stream_stat(pjmedia_session *session,
 						     pjmedia_stream_stat *sta);
 
 /**
+ * Dial DTMF digit to the stream, using RFC 2833 mechanism.
+ *
+ * @param session	The media session.
+ * @param index		The stream index.
+ * @param ascii_digits	String of ASCII digits (i.e. 0-9*#A-B).
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_session_dial_dtmf( pjmedia_session *session,
+					        unsigned index,
+						const pj_str_t *ascii_digits );
+
+
+/**
+ * Check if the specified stream has received DTMF digits.
+ *
+ * @param session	The media session.
+ * @param index		The stream index.
+ *
+ * @return		Non-zero (PJ_TRUE) if the stream has DTMF digits.
+ */
+PJ_DECL(pj_status_t) pjmedia_session_check_dtmf( pjmedia_session *session,
+					         unsigned index);
+
+
+/**
+ * Retrieve DTMF digits from the specified stream.
+ *
+ * @param session	The media session.
+ * @param index		The stream index.
+ * @param ascii_digits	Buffer to receive the digits. The length of this
+ *			buffer is indicated in the "size" argument.
+ * @param size		On input, contains the maximum digits to be copied
+ *			to the buffer.
+ *			On output, it contains the actual digits that has
+ *			been copied to the buffer.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_session_get_dtmf( pjmedia_session *session,
+					       unsigned index,
+					       char *ascii_digits,
+					       unsigned *size );
+
+/**
  * Destroy media session.
  *
  * @param session	The media session.
diff --git a/pjmedia/include/pjmedia/stream.h b/pjmedia/include/pjmedia/stream.h
index 6a685e06..67975566 100644
--- a/pjmedia/include/pjmedia/stream.h
+++ b/pjmedia/include/pjmedia/stream.h
@@ -71,8 +71,8 @@ struct pjmedia_stream_info
     pjmedia_sock_info	sock_info;  /**< Media transport (RTP/RTCP sockets) */
     pj_sockaddr_in	rem_addr;   /**< Remote RTP address		    */
     pjmedia_codec_info	fmt;	    /**< Codec format info.		    */
-    unsigned		tx_event_pt;/**< Outgoing pt for telephone-events.  */
-    unsigned		rx_event_pt;/**< Incoming pt for telephone-events.  */
+    int		        tx_event_pt;/**< Outgoing pt for telephone-events.  */
+    int			rx_event_pt;/**< Incoming pt for telephone-events.  */
     pj_uint32_t		ssrc;	    /**< RTP SSRC.			    */
     int			jb_min;	    /**< Jitter buffer min delay.	    */
     int			jb_max;	    /**< Jitter buffer max delay.	    */
@@ -110,6 +110,7 @@ struct pjmedia_stream_stat
  *			number of memory may be needed because jitter
  *			buffer needs to preallocate some storage.
  * @param info		Stream information.
+ * @param user_data	Arbitrary user data (for future callback feature).
  * @param p_stream	Pointer to receive the media stream.
  *
  * @return		PJ_SUCCESS on success.
@@ -117,6 +118,7 @@ struct pjmedia_stream_stat
 PJ_DECL(pj_status_t) pjmedia_stream_create(pjmedia_endpt *endpt,
 					   pj_pool_t *pool,
 					   const pjmedia_stream_info *info,
+					   void *user_data,
 					   pjmedia_stream **p_stream);
 
 /**
@@ -191,14 +193,47 @@ PJ_DECL(pj_status_t) pjmedia_stream_resume(pjmedia_stream *stream,
  * only valid for audio stream.
  *
  * @param stream	The media stream.
- * @param digit		A single digit ('0123456789*#ABCD').
+ * @param ascii_digit	String containing digits to be sent to remote.
+ *			Currently the maximum number of digits are 32.
  *
  * @return		PJ_SUCCESS on success.
  */
 PJ_DECL(pj_status_t) pjmedia_stream_dial_dtmf(pjmedia_stream *stream,
-					      const pj_str_t *digit_char);
+					      const pj_str_t *ascii_digit);
 
 
+/**
+ * Check if the stream has incoming DTMF digits in the incoming DTMF
+ * queue. Incoming DTMF digits received via RFC 2833 mechanism are
+ * saved in the incoming digits queue.
+ *
+ * @param stream	The media stream.
+ *
+ * @return		Non-zero (PJ_TRUE) if the stream has received DTMF
+ *			digits in the .
+ */
+PJ_DECL(pj_bool_t) pjmedia_stream_check_dtmf(pjmedia_stream *stream);
+
+
+/**
+ * Retrieve the incoming DTMF digits from the stream. Note that the digits
+ * buffer will not be NULL terminated.
+ *
+ * @param stream	The media stream.
+ * @param ascii_digits	Buffer to receive the digits. The length of this
+ *			buffer is indicated in the "size" argument.
+ * @param size		On input, contains the maximum digits to be copied
+ *			to the buffer.
+ *			On output, it contains the actual digits that has
+ *			been copied to the buffer.
+ *
+ * @return		Non-zero (PJ_TRUE) if the stream has received DTMF
+ *			digits in the .
+ */
+PJ_DECL(pj_status_t) pjmedia_stream_get_dtmf( pjmedia_stream *stream,
+					      char *ascii_digits,
+					      unsigned *size);
+
 
 /**
  * @}
diff --git a/pjmedia/src/pjmedia/endpoint.c b/pjmedia/src/pjmedia/endpoint.c
index 24f409b1..99a32729 100644
--- a/pjmedia/src/pjmedia/endpoint.c
+++ b/pjmedia/src/pjmedia/endpoint.c
@@ -263,9 +263,9 @@ PJ_DEF(pj_status_t) pjmedia_endpt_create_sdp( pjmedia_endpt *endpt,
     m->attr[m->attr_count++] = attr;
 
 #if 1
-    //
-    // Test: add telephony events
-    //
+    /*
+     * Add support telephony event
+     */
     m->desc.fmt[m->desc.fmt_count++] = pj_str("101");
     /* Add rtpmap. */
     attr = pj_pool_zalloc(pool, sizeof(pjmedia_sdp_attr));
diff --git a/pjmedia/src/pjmedia/errno.c b/pjmedia/src/pjmedia/errno.c
index bce55a95..3a91deff 100644
--- a/pjmedia/src/pjmedia/errno.c
+++ b/pjmedia/src/pjmedia/errno.c
@@ -89,6 +89,8 @@ static const struct
     { PJMEDIA_EINVALIDPT,	    "Invalid media payload type" },
     { PJMEDIA_EMISSINGRTPMAP,	    "Missing rtpmap in media description" },
     { PJMEDIA_EINVALIMEDIATYPE,	    "Invalid media type" },
+    { PJMEDIA_EREMOTENODTMF,	    "Remote does not support DTMF" },
+    { PJMEDIA_RTP_EINDTMF,	    "Invalid DTMF digit" },
 
     /* RTP session errors. */
     { PJMEDIA_RTP_EINPKT,	    "Invalid RTP packet" },
@@ -100,7 +102,16 @@ static const struct
     { PJMEDIA_RTP_ESESSRESTART,	    "RTP session restarted" },
     { PJMEDIA_RTP_ESESSPROBATION,   "RTP session in probation" },
     { PJMEDIA_RTP_EBADSEQ,	    "Bad sequence number in RTP packet" },
-
+    { PJMEDIA_RTP_EBADDEST,	    "RTP media port destination is not configured" },
+    { PJMEDIA_RTP_ENOCONFIG,	    "RTP is not configured" },
+    
+    /* Media port errors: */
+    { PJMEDIA_ENOTCOMPATIBLE,	    "Media ports are not compatible" },
+    { PJMEDIA_ENCCLOCKRATE,	    "Media ports have incompatible clock rate" },
+    { PJMEDIA_ENCSAMPLESPFRAME,	    "Media ports have incompatible samples per frame" },
+    { PJMEDIA_ENCTYPE,		    "Media ports have incompatible media type" },
+    { PJMEDIA_ENCBITS,		    "Media ports have incompatible bits per sample" },
+    { PJMEDIA_ENCBYTES,		    "Media ports have incompatible bytes per frame" },
 };
 
 
diff --git a/pjmedia/src/pjmedia/session.c b/pjmedia/src/pjmedia/session.c
index 884d8a9f..59960941 100644
--- a/pjmedia/src/pjmedia/session.c
+++ b/pjmedia/src/pjmedia/session.c
@@ -33,6 +33,7 @@ struct pjmedia_session
     unsigned		    stream_cnt;
     pjmedia_stream_info	    stream_info[PJMEDIA_MAX_SDP_MEDIA];
     pjmedia_stream	   *stream[PJMEDIA_MAX_SDP_MEDIA];
+    void		   *user_data;
 };
 
 #define THIS_FILE		"session.c"
@@ -47,6 +48,7 @@ static const pj_str_t ID_IP4 = { "IP4", 3};
 static const pj_str_t ID_RTP_AVP = { "RTP/AVP", 7 };
 static const pj_str_t ID_SDP_NAME = { "pjmedia", 7 };
 static const pj_str_t ID_RTPMAP = { "rtpmap", 6 };
+static const pj_str_t ID_TELEPHONE_EVENT = { "telephone-event", 15 };
 
 static const pj_str_t STR_INACTIVE = { "inactive", 8 };
 static const pj_str_t STR_SENDRECV = { "sendrecv", 8 };
@@ -66,6 +68,7 @@ static pj_status_t create_stream_info_from_sdp(pj_pool_t *pool,
 {
     const pjmedia_sdp_attr *attr;
     pjmedia_sdp_rtpmap *rtpmap;
+    unsigned i;
     pj_status_t status;
 
 
@@ -151,7 +154,8 @@ static pj_status_t create_stream_info_from_sdp(pj_pool_t *pool,
      * For this version of PJMEDIA, we do not support static payload
      * type without rtpmap.
      */
-    attr = pjmedia_sdp_media_find_attr(local_m, &ID_RTPMAP, NULL);
+    attr = pjmedia_sdp_media_find_attr(local_m, &ID_RTPMAP, 
+				       &local_m->desc.fmt[0]);
     if (attr == NULL)
 	return PJMEDIA_EMISSINGRTPMAP;
 
@@ -166,6 +170,39 @@ static pj_status_t create_stream_info_from_sdp(pj_pool_t *pool,
     pj_strdup(pool, &si->fmt.encoding_name, &rtpmap->enc_name);
     si->fmt.sample_rate = rtpmap->clock_rate;
 
+    /* Get local DTMF payload type */
+    si->tx_event_pt = -1;
+    for (i=0; i<local_m->attr_count; ++i) {
+	pjmedia_sdp_rtpmap r;
+
+	attr = local_m->attr[i];
+	if (pj_strcmp(&attr->name, &ID_RTPMAP) != 0)
+	    continue;
+	if (pjmedia_sdp_attr_get_rtpmap(attr, &r) != PJ_SUCCESS)
+	    continue;
+	if (pj_strcmp(&r.enc_name, &ID_TELEPHONE_EVENT) == 0) {
+	    si->tx_event_pt = pj_strtoul(&r.pt);
+	    break;
+	}
+    }
+
+    /* Get remote DTMF payload type */
+    si->rx_event_pt = -1;
+    for (i=0; i<rem_m->attr_count; ++i) {
+	pjmedia_sdp_rtpmap r;
+
+	attr = rem_m->attr[i];
+	if (pj_strcmp(&attr->name, &ID_RTPMAP) != 0)
+	    continue;
+	if (pjmedia_sdp_attr_get_rtpmap(attr, &r) != PJ_SUCCESS)
+	    continue;
+	if (pj_strcmp(&r.enc_name, &ID_TELEPHONE_EVENT) == 0) {
+	    si->rx_event_pt = pj_strtoul(&r.pt);
+	    break;
+	}
+    }
+
+
     /* Leave SSRC to zero. */
 
     /* Leave jitter buffer parameter. */
@@ -182,6 +219,7 @@ PJ_DEF(pj_status_t) pjmedia_session_create( pjmedia_endpt *endpt,
 					    const pjmedia_sock_info skinfo[],
 					    const pjmedia_sdp_session *local_sdp,
 					    const pjmedia_sdp_session *rem_sdp,
+					    void *user_data,
 					    pjmedia_session **p_session )
 {
     pj_pool_t *pool;
@@ -203,6 +241,7 @@ PJ_DEF(pj_status_t) pjmedia_session_create( pjmedia_endpt *endpt,
     session->pool = pool;
     session->endpt = endpt;
     session->stream_cnt = stream_cnt;
+    session->user_data = user_data;
     
     /* Stream count is the lower number of stream_cnt or SDP m= lines count */
     if (stream_cnt < local_sdp->media_count)
@@ -239,6 +278,7 @@ PJ_DEF(pj_status_t) pjmedia_session_create( pjmedia_endpt *endpt,
 
 	status = pjmedia_stream_create(endpt, session->pool,
 				       &session->stream_info[i],
+				       session,
 				       &session->stream[i]);
 	if (status == PJ_SUCCESS)
 	    status = pjmedia_stream_start(session->stream[i]);
@@ -385,6 +425,9 @@ PJ_DEF(pj_status_t) pjmedia_session_enum_streams(const pjmedia_session *session,
 }
 
 
+/*
+ * Get the port interface.
+ */
 PJ_DEF(pj_status_t) pjmedia_session_get_port(  pjmedia_session *session,
 					       unsigned index,
 					       pjmedia_port **p_port)
@@ -392,7 +435,7 @@ PJ_DEF(pj_status_t) pjmedia_session_get_port(  pjmedia_session *session,
     return pjmedia_stream_get_port( session->stream[index], p_port);
 }
 
-/**
+/*
  * Get statistics
  */
 PJ_DEF(pj_status_t) pjmedia_session_get_stream_stat( pjmedia_session *session,
@@ -406,3 +449,37 @@ PJ_DEF(pj_status_t) pjmedia_session_get_stream_stat( pjmedia_session *session,
 }
 
 
+/*
+ * Dial DTMF digit to the stream, using RFC 2833 mechanism.
+ */
+PJ_DEF(pj_status_t) pjmedia_session_dial_dtmf( pjmedia_session *session,
+					       unsigned index,
+					       const pj_str_t *ascii_digits )
+{
+    PJ_ASSERT_RETURN(session && ascii_digits, PJ_EINVAL);
+    return pjmedia_stream_dial_dtmf(session->stream[index], ascii_digits);
+}
+
+/*
+ * Check if the specified stream has received DTMF digits.
+ */
+PJ_DEF(pj_status_t) pjmedia_session_check_dtmf( pjmedia_session *session,
+					        unsigned index )
+{
+    PJ_ASSERT_RETURN(session, PJ_EINVAL);
+    return pjmedia_stream_check_dtmf(session->stream[index]);
+}
+
+
+/*
+ * Retrieve DTMF digits from the specified stream.
+ */
+PJ_DEF(pj_status_t) pjmedia_session_get_dtmf( pjmedia_session *session,
+					      unsigned index,
+					      char *ascii_digits,
+					      unsigned *size )
+{
+    PJ_ASSERT_RETURN(session && ascii_digits && size, PJ_EINVAL);
+    return pjmedia_stream_get_dtmf(session->stream[index], ascii_digits,
+				   size);
+}
diff --git a/pjmedia/src/pjmedia/stream.c b/pjmedia/src/pjmedia/stream.c
index b1dc90f1..a5737009 100644
--- a/pjmedia/src/pjmedia/stream.c
+++ b/pjmedia/src/pjmedia/stream.c
@@ -21,16 +21,16 @@
 #include <pjmedia/rtp.h>
 #include <pjmedia/rtcp.h>
 #include <pjmedia/jbuf.h>
-#include <pj/os.h>
+#include <pj/array.h>
+#include <pj/assert.h>
 #include <pj/ctype.h>
+#include <pj/compat/socket.h>
+#include <pj/errno.h>
 #include <pj/log.h>
-#include <pj/string.h>	    /* memcpy() */
+#include <pj/os.h>
 #include <pj/pool.h>
-#include <pj/assert.h>
-#include <pj/compat/socket.h>
 #include <pj/sock_select.h>
-#include <pj/errno.h>
-#include <stdlib.h>
+#include <pj/string.h>	    /* memcpy() */
 
 
 #define THIS_FILE			"stream.c"
@@ -68,7 +68,6 @@ struct dtmf
 {
     int		    event;
     pj_uint32_t	    start_ts;
-    pj_uint32_t	    end_ts;
 };
 
 /**
@@ -86,6 +85,7 @@ struct pjmedia_stream
 
     pjmedia_dir		     dir;	    /**< Stream direction.	    */
     pjmedia_stream_stat	     stat;	    /**< Stream statistics.	    */
+    void		    *user_data;	    /**< User data.		    */
 
     pjmedia_codec_mgr	    *codec_mgr;	    /**< Codec manager instance.    */
     pjmedia_codec	    *codec;	    /**< Codec instance being used. */
@@ -103,8 +103,16 @@ struct pjmedia_stream
     pj_thread_t		    *thread;	    /**< Jitter buffer's thread.    */
 
     /* RFC 2833 DTMF transmission queue: */
-    int			     dtmf_count;    /**< # of digits in queue.	    */
-    struct dtmf		     dtmf_queue[32];/**< Outgoing dtmf queue.	    */
+    int			     tx_event_pt;   /**< Outgoing pt for dtmf.	    */
+    int			     tx_dtmf_count; /**< # of digits in tx dtmf buf.*/
+    struct dtmf		     tx_dtmf_buf[32];/**< Outgoing dtmf queue.	    */
+
+    /* Incoming DTMF: */
+    int			     rx_event_pt;   /**< Incoming pt for dtmf.	    */
+    int			     last_dtmf;	    /**< Current digit, or -1.	    */
+    pj_uint32_t		     last_dtmf_dur; /**< Start ts for cur digit.    */
+    unsigned		     rx_dtmf_count; /**< # of digits in dtmf rx buf.*/
+    char		     rx_dtmf_buf[32];/**< Incoming DTMF buffer.	    */
 };
 
 
@@ -193,19 +201,38 @@ static pj_status_t get_frame( pjmedia_port *port, pjmedia_frame *frame)
 /*
  * Transmit DTMF
  */
-static void transmit_dtmf(pjmedia_stream *stream, 
+static void create_dtmf_payload(pjmedia_stream *stream, 
 			  struct pjmedia_frame *frame_out)
 {
     pjmedia_rtp_dtmf_event *event;
-    struct dtmf *digit = &stream->dtmf_queue[0];
+    struct dtmf *digit = &stream->tx_dtmf_buf[0];
+    unsigned duration;
     pj_uint32_t cur_ts;
 
+    pj_assert(sizeof(pjmedia_rtp_dtmf_event) == 4);
+
     event = frame_out->buf;
     cur_ts = pj_ntohl(stream->enc->rtp.out_hdr.ts);
+    duration = cur_ts - digit->start_ts;
 
     event->event = (pj_uint8_t)digit->event;
     event->e_vol = 10;
-    event->duration = pj_htonl(cur_ts - digit->start_ts);
+    event->duration = pj_htons((pj_uint16_t)duration);
+
+    if (duration >= PJMEDIA_DTMF_DURATION) {
+	event->e_vol |= 0x80;
+
+	/* Prepare next digit. */
+	pj_mutex_lock(stream->jb_mutex);
+	pj_array_erase(stream->tx_dtmf_buf, sizeof(stream->tx_dtmf_buf[0]),
+		       stream->tx_dtmf_count, 0);
+	--stream->tx_dtmf_count;
+
+	stream->tx_dtmf_buf[0].start_ts = cur_ts;
+	pj_mutex_unlock(stream->jb_mutex);
+    }
+
+    frame_out->size = 4;
 }
 
 /**
@@ -227,7 +254,6 @@ static pj_status_t put_frame( pjmedia_port *port,
     int rtphdrlen;
     pj_ssize_t sent;
 
-
     /* Check if stream is quitting. */
     if (stream->quit_flag)
 	return -1;
@@ -241,8 +267,17 @@ static pj_status_t put_frame( pjmedia_port *port,
     /* If we have DTMF digits in the queue, transmit the digits. 
      * Otherwise encode the PCM buffer.
      */
-    if (stream->dtmf_count) {
-	transmit_dtmf(stream, &frame_out);
+    if (stream->tx_dtmf_count) {
+
+	create_dtmf_payload(stream, &frame_out);
+
+	/* Encapsulate. */
+	status = pjmedia_rtp_encode_rtp( &channel->rtp, 
+					 stream->tx_event_pt, 0, 
+					 frame_out.size, ts_len, 
+					 (const void**)&rtphdr, 
+					 &rtphdrlen);
+
     } else {
 	unsigned max_size;
 
@@ -254,13 +289,15 @@ static pj_status_t put_frame( pjmedia_port *port,
 	    TRACE_((THIS_FILE, "Codec encode() error", status));
 	    return status;
 	}
+
+	/* Encapsulate. */
+	status = pjmedia_rtp_encode_rtp( &channel->rtp, 
+					 channel->pt, 0, 
+					 frame_out.size, ts_len, 
+					 (const void**)&rtphdr, 
+					 &rtphdrlen);
     }
 
-    /* Encapsulate. */
-    status = pjmedia_rtp_encode_rtp( &channel->rtp, 
-				channel->pt, 0, 
-				frame_out.size, ts_len, 
-				(const void**)&rtphdr, &rtphdrlen);
     if (status != 0) {
 	TRACE_((THIS_FILE, "RTP encode_rtp() error", status));
 	return status;
@@ -289,7 +326,7 @@ static pj_status_t put_frame( pjmedia_port *port,
     return PJ_SUCCESS;
 }
 
-
+#if 0
 static void dump_bin(const char *buf, unsigned len)
 {
     unsigned i;
@@ -312,6 +349,68 @@ static void dump_bin(const char *buf, unsigned len)
     }
     PJ_LOG(3,(THIS_FILE, "end dump"));
 }
+#endif
+
+/*
+ * Handle incoming DTMF digits.
+ */
+static void handle_incoming_dtmf( pjmedia_stream *stream, 
+				  const void *payload, unsigned payloadlen)
+{
+    static const char digitmap[16] = { '0', '1', '2', '3', 
+				       '4', '5', '6', '7', 
+				       '8', '9', '*', '#',
+				       'A', 'B', 'C', 'D'};
+    const pjmedia_rtp_dtmf_event *event = payload;
+
+    /* Check compiler packing. */
+    pj_assert(sizeof(pjmedia_rtp_dtmf_event)==4);
+
+    /* Must have sufficient length before we proceed. */
+    if (payloadlen < sizeof(pjmedia_rtp_dtmf_event))
+	return;
+
+    //dump_bin(payload, payloadlen);
+
+    /* Check if this is the same/current digit of the last packet. */
+    if (stream->last_dtmf != -1 &&
+	event->event == stream->last_dtmf &&
+	pj_ntohs(event->duration) >= stream->last_dtmf_dur)
+    {
+	/* Yes, this is the same event. */
+	stream->last_dtmf_dur = pj_ntohs(event->duration);
+	return;
+    }
+
+    /* Ignore unknown event. */
+    if (event->event > 15) {
+	PJ_LOG(5,(THIS_FILE, "Ignored RTP pkt with bad DTMF event %d",
+    			     event->event));
+	return;
+    }
+
+    /* New event! */
+    PJ_LOG(5,(THIS_FILE, "Received DTMF digit %c, vol=%d",
+    			 digitmap[event->event],
+    			 (event->e_vol & 0x3F)));
+
+    stream->last_dtmf = event->event;
+    stream->last_dtmf_dur = pj_ntohs(event->duration);
+
+    /* By convention, we use jitter buffer's mutex to access shared
+     * DTMF variables.
+     */
+    pj_mutex_lock(stream->jb_mutex);
+    if (stream->rx_dtmf_count >= PJ_ARRAY_SIZE(stream->rx_dtmf_buf)) {
+	/* DTMF digits overflow.  Discard the oldest digit. */
+	pj_array_erase(stream->rx_dtmf_buf, sizeof(stream->rx_dtmf_buf[0]),
+		       stream->rx_dtmf_count, 0);
+	--stream->rx_dtmf_count;
+    }
+    stream->rx_dtmf_buf[stream->rx_dtmf_count++] = digitmap[event->event];
+    pj_mutex_unlock(stream->jb_mutex);
+}
+
 
 /*
  * This thread will poll the socket for incoming packets, and put
@@ -376,12 +475,11 @@ static int PJ_THREAD_FUNC jitter_buffer_thread (void*arg)
 	    continue;
 	}
 
-#if 1
-	if (hdr->pt == 101) {
-	    dump_bin((char*)payload, payloadlen);
+	/* Handle incoming DTMF. */
+	if (hdr->pt == stream->rx_event_pt) {
+	    handle_incoming_dtmf(stream, payload, payloadlen);
 	    continue;
 	}
-#endif
 
 	status = pjmedia_rtp_session_update(&channel->rtp, hdr);
 	if (status != 0 && 
@@ -520,6 +618,7 @@ static pj_status_t create_channel( pj_pool_t *pool,
 PJ_DEF(pj_status_t) pjmedia_stream_create( pjmedia_endpt *endpt,
 					   pj_pool_t *pool,
 					   const pjmedia_stream_info *info,
+					   void *user_data,
 					   pjmedia_stream **p_stream)
 
 {
@@ -552,9 +651,14 @@ PJ_DEF(pj_status_t) pjmedia_stream_create( pjmedia_endpt *endpt,
     /* Init stream: */
    
     stream->dir = info->dir;
+    stream->user_data = user_data;
     stream->codec_mgr = pjmedia_endpt_get_codec_mgr(endpt);
     stream->skinfo = info->sock_info;
     stream->rem_rtp_addr = info->rem_addr;
+    stream->tx_event_pt = info->tx_event_pt;
+    stream->rx_event_pt = info->rx_event_pt;
+    stream->last_dtmf = -1;
+
 
     PJ_TODO(INITIALIZE_RTCP_REMOTE_ADDRESS);
 
@@ -824,10 +928,15 @@ PJ_DEF(pj_status_t) pjmedia_stream_dial_dtmf( pjmedia_stream *stream,
      */
     PJ_ASSERT_RETURN(stream && digit_char, PJ_EINVAL);
 
+    /* Check that remote can receive DTMF events. */
+    if (stream->tx_event_pt < 0) {
+	return PJMEDIA_RTP_EINDTMF;
+    }
+    
     pj_mutex_lock(stream->jb_mutex);
     
-    if (stream->dtmf_count+digit_char->slen >=
-	PJ_ARRAY_SIZE(stream->dtmf_queue))
+    if (stream->tx_dtmf_count+digit_char->slen >=
+	PJ_ARRAY_SIZE(stream->tx_dtmf_buf))
     {
 	status = PJ_ETOOMANY;
     } else {
@@ -863,27 +972,24 @@ PJ_DEF(pj_status_t) pjmedia_stream_dial_dtmf( pjmedia_stream *stream,
 		break;
 	    }
 
-	    stream->dtmf_queue[stream->dtmf_count+1].event = pt;
-	    stream->dtmf_queue[stream->dtmf_count+1].start_ts = start_ts;
-	    stream->dtmf_queue[stream->dtmf_count+1].end_ts = 
-		start_ts + PJMEDIA_DTMF_DURATION;
-
-	    start_ts += PJMEDIA_DTMF_DURATION + 320;
+	    stream->tx_dtmf_buf[stream->tx_dtmf_count+i].event = pt;
 	}
 
 	if (status != PJ_SUCCESS)
 	    goto on_return;
 
-	if (stream->dtmf_count ==0) {
+	/* Init start_ts and end_ts only for the first digit.
+	 * Subsequent digits are initialized on the fly.
+	 */
+	if (stream->tx_dtmf_count ==0) {
 	    pj_uint32_t start_ts;
 
 	    start_ts = pj_ntohl(stream->enc->rtp.out_hdr.ts);
-	    stream->dtmf_queue[0].start_ts = start_ts;
-	    stream->dtmf_queue[0].end_ts = start_ts + PJMEDIA_DTMF_DURATION;
+	    stream->tx_dtmf_buf[0].start_ts = start_ts;
 	}
 
 	/* Increment digit count only if all digits are valid. */
-	stream->dtmf_count += digit_char->slen;
+	stream->tx_dtmf_count += digit_char->slen;
 
     }
 
@@ -893,3 +999,46 @@ on_return:
     return status;
 }
 
+
+/*
+ * See if we have DTMF digits in the rx buffer.
+ */
+PJ_DEF(pj_bool_t) pjmedia_stream_check_dtmf(pjmedia_stream *stream)
+{
+    return stream->rx_dtmf_count != 0;
+}
+
+
+/*
+ * Retrieve incoming DTMF digits from the stream's DTMF buffer.
+ */
+PJ_DEF(pj_status_t) pjmedia_stream_get_dtmf( pjmedia_stream *stream,
+					     char *digits,
+					     unsigned *size)
+{
+    PJ_ASSERT_RETURN(stream && digits && size, PJ_EINVAL);
+
+    pj_assert(sizeof(stream->rx_dtmf_buf[0]) == 0);
+
+    /* By convention, we use jitter buffer's mutex to access DTMF
+     * digits resources.
+     */
+    pj_mutex_lock(stream->jb_mutex);
+
+    if (stream->rx_dtmf_count < *size)
+	*size = stream->rx_dtmf_count;
+
+    if (*size) {
+	pj_memcpy(digits, stream->rx_dtmf_buf, *size);
+	stream->rx_dtmf_count -= *size;
+	if (stream->rx_dtmf_count) {
+	    pj_memmove(stream->rx_dtmf_buf,
+		       &stream->rx_dtmf_buf[*size],
+		       stream->rx_dtmf_count);
+	}
+    }
+
+    pj_mutex_unlock(stream->jb_mutex);
+
+    return PJ_SUCCESS;
+}
diff --git a/pjsip/src/pjsua/main.c b/pjsip/src/pjsua/main.c
index 4068e77f..5508e069 100644
--- a/pjsip/src/pjsua/main.c
+++ b/pjsip/src/pjsua/main.c
@@ -139,7 +139,7 @@ static void keystroke_help(void)
     puts("|  H  Hold call                |     Conference Command   |                   |");
     puts("|  v  re-inVite (release hold) | cl  List ports           |                   |");
     puts("|  x  Xfer call                | cc  Connect port         |                   |");
-    puts("|                              | cd  Disconnect port      |                   |");
+    puts("|  #  Send DTMF string         | cd  Disconnect port      |                   |");
     puts("+------------------------------+--------------------------+-------------------+");
     puts("|  q  QUIT                                                                    |");
     puts("+=============================================================================+");
@@ -440,6 +440,37 @@ static void ui_console_main(void)
 	    }
 	    break;
 
+	case '#':
+	    /*
+	     * Send DTMF strings.
+	     */
+	    if (inv_session == &pjsua.inv_list) {
+		
+		PJ_LOG(3,(THIS_FILE, "No current call"));
+
+	    } else if (inv_session->session == NULL) {
+
+		PJ_LOG(3,(THIS_FILE, "Media is not established yet!"));
+
+	    } else {
+		pj_str_t digits;
+		pj_status_t status;
+
+		if (!simple_input("DTMF strings to send (0-9*#A-B)", buf, 
+				  sizeof(buf)))
+			break;
+
+		digits = pj_str(buf);
+		status = pjmedia_session_dial_dtmf(inv_session->session, 0, 
+						   &digits);
+		if (status != PJ_SUCCESS) {
+		    pjsua_perror(THIS_FILE, "Unable to send DTMF", status);
+		} else {
+		    puts("DTMF digits enqueued for transmission");
+		}
+	    }
+	    break;
+
 	case 's':
 	case 'u':
 	    /*
diff --git a/pjsip/src/pjsua/pjsua_inv.c b/pjsip/src/pjsua/pjsua_inv.c
index 34bf651f..824943cd 100644
--- a/pjsip/src/pjsua/pjsua_inv.c
+++ b/pjsip/src/pjsua/pjsua_inv.c
@@ -716,6 +716,7 @@ void pjsua_inv_on_media_update(pjsip_inv_session *inv, pj_status_t status)
     status = pjmedia_session_create( pjsua.med_endpt, 1, 
 				     &pjsua.med_sock_info[inv_data->call_slot],
 				     local_sdp, remote_sdp, 
+				     inv_data,
 				     &inv_data->session );
     if (status != PJ_SUCCESS) {
 	pjsua_perror(THIS_FILE, "Unable to create media session",