Ticket #513: Support for RTCP XR (initial patch)

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@1942 74dad513-b988-da41-8d7b-12977e46ad98

4 files changed, 571 insertions, 5 deletions

diff --git a/pjmedia/include/pjmedia/config.h b/pjmedia/include/pjmedia/config.h
index 240432eb..587055eb 100644
--- a/pjmedia/include/pjmedia/config.h
+++ b/pjmedia/include/pjmedia/config.h
@@ -339,6 +339,30 @@
 #   define  PJMEDIA_RTCP_IGNORE_FIRST_PACKETS	25
 #endif
 
+/**
+ * Specify whether RTCP XR support should be built into PJMEDIA. Disabling
+ * this feature will reduce footprint slightly. Note that even when this 
+ * setting is enabled, RTCP XR processing will only be performed in stream 
+ * if it is enabled on run-time on per stream basis. See  
+ * PJMEDIA_STREAM_ENABLE_XR setting for more info.
+ *
+ * Default: 1 (yes).
+ */
+#ifndef PJMEDIA_HAS_RTCP_XR
+#   define PJMEDIA_HAS_RTCP_XR			0
+#endif
+
+
+/**
+ * The RTCP XR feature is activated and used by stream if \a enable_rtcp_xr
+ * field of \a pjmedia_stream_info structure is non-zero. This setting 
+ * controls the default value of this field.
+ *
+ * Default: 0 (disabled)
+ */
+#ifndef PJMEDIA_STREAM_ENABLE_XR
+#   define PJMEDIA_STREAM_ENABLE_XR		0
+#endif
 
 /**
  * Specify how long (in miliseconds) the stream should suspend the
diff --git a/pjmedia/include/pjmedia/jbuf.h b/pjmedia/include/pjmedia/jbuf.h
index 8a06a64b..a527d57b 100644
--- a/pjmedia/include/pjmedia/jbuf.h
+++ b/pjmedia/include/pjmedia/jbuf.h
@@ -76,6 +76,7 @@ struct pjmedia_jb_state
     unsigned	min_prefetch;	    /**< Minimum allowed prefetch, in frms. */
     unsigned	max_prefetch;	    /**< Maximum allowed prefetch, in frms. */
     unsigned	size;		    /**< Current buffer size, in frames.    */
+    unsigned	max_size;	    /**< Maximum size ever.		    */
 };
 
 
@@ -184,7 +185,6 @@ PJ_DECL(pj_status_t) pjmedia_jbuf_destroy(pjmedia_jbuf *jb);
  */
 PJ_DECL(pj_status_t) pjmedia_jbuf_reset(pjmedia_jbuf *jb);
 
-
 /**
  * Put a frame to the jitter buffer. If the frame can be accepted (based
  * on the sequence number), the jitter buffer will copy the frame and put
@@ -198,8 +198,6 @@ PJ_DECL(pj_status_t) pjmedia_jbuf_reset(pjmedia_jbuf *jb);
  *			buffer.
  * @param size		The frame size.
  * @param frame_seq	The frame sequence number.
- *
- * @return		PJ_SUCCESS on success.
  */
 PJ_DECL(void) pjmedia_jbuf_put_frame( pjmedia_jbuf *jb, 
 				      const void *frame, 
@@ -207,6 +205,27 @@ PJ_DECL(void) pjmedia_jbuf_put_frame( pjmedia_jbuf *jb,
 				      int frame_seq);
 
 /**
+ * Put a frame to the jitter buffer. If the frame can be accepted (based
+ * on the sequence number), the jitter buffer will copy the frame and put
+ * it in the appropriate position in the buffer.
+ *
+ * Application MUST manage it's own synchronization when multiple threads
+ * are accessing the jitter buffer at the same time.
+ *
+ * @param jb		The jitter buffer.
+ * @param frame		Pointer to frame buffer to be stored in the jitter
+ *			buffer.
+ * @param size		The frame size.
+ * @param frame_seq	The frame sequence number.
+ * @param discarded	Flag whether the frame is discarded by jitter buffer.
+ */
+PJ_DECL(void) pjmedia_jbuf_put_frame2( pjmedia_jbuf *jb, 
+				       const void *frame, 
+				       pj_size_t size, 
+				       int frame_seq,
+				       pj_bool_t *discarded);
+
+/**
  * Get a frame from the jitter buffer. The jitter buffer will return the
  * oldest frame from it's buffer, when it is available.
  *
diff --git a/pjmedia/include/pjmedia/rtcp.h b/pjmedia/include/pjmedia/rtcp.h
index 4c02e8b2..2633224e 100644
--- a/pjmedia/include/pjmedia/rtcp.h
+++ b/pjmedia/include/pjmedia/rtcp.h
@@ -25,6 +25,7 @@
  */
 
 #include <pjmedia/types.h>
+#include <pjmedia/rtcp_xr.h>
 #include <pjmedia/rtp.h>
 
 
@@ -246,7 +247,6 @@ typedef struct pjmedia_rtcp_stat pjmedia_rtcp_stat;
   typedef pj_uint32_t PJMEDIA_AVG_JITTER_TYPE;
 #endif
 
-
 /**
  * RTCP session is used to monitor the RTP session of one endpoint. There
  * should only be one RTCP session for a bidirectional RTP streams.
@@ -254,7 +254,7 @@ typedef struct pjmedia_rtcp_stat pjmedia_rtcp_stat;
 struct pjmedia_rtcp_session
 {
     char		   *name;	/**< Name identification.	    */
-    pjmedia_rtcp_sr_pkt	    rtcp_sr_pkt;/**< Cached RTCP packet.	    */
+    pjmedia_rtcp_sr_pkt	    rtcp_sr_pkt;/**< Cached RTCP SR packet.	    */
     pjmedia_rtcp_rr_pkt	    rtcp_rr_pkt;/**< Cached RTCP RR packet.	    */
     
     pjmedia_rtp_seq_session seq_ctrl;	/**< RTCP sequence number control.  */
@@ -281,6 +281,19 @@ struct pjmedia_rtcp_session
      * from being rounded-down to nearest integer.
      */
     PJMEDIA_AVG_JITTER_TYPE avg_jitter;	/**< Average RX jitter.		    */
+
+#if defined(PJMEDIA_HAS_RTCP_XR) && (PJMEDIA_HAS_RTCP_XR != 0)
+    /**
+     * Specify whether RTCP XR processing is enabled on this session.
+     */
+    pj_bool_t		    xr_enabled;
+
+    /**
+     * RTCP XR session, only valid if RTCP XR processing is enabled
+     * on this session.
+     */
+    pjmedia_rtcp_xr_session xr_session;
+#endif
 };
 
 /**
@@ -342,6 +355,23 @@ PJ_DECL(void) pjmedia_rtcp_rx_rtp( pjmedia_rtcp_session *session,
 
 
 /**
+ * Call this function everytime an RTP packet is received to let the RTCP
+ * session do its internal calculations.
+ *
+ * @param session   The session.
+ * @param seq	    The RTP packet sequence number, in host byte order.
+ * @param ts	    The RTP packet timestamp, in host byte order.
+ * @param payload   Size of the payload.
+ * @param discarded Flag to specify whether the packet is discarded.
+ */
+PJ_DECL(void) pjmedia_rtcp_rx_rtp2(pjmedia_rtcp_session *session, 
+				   unsigned seq, 
+				   unsigned ts,
+				   unsigned payload,
+				   pj_bool_t discarded);
+
+
+/**
  * Call this function everytime an RTP packet is sent to let the RTCP session
  * do its internal calculations.
  *
@@ -385,6 +415,19 @@ PJ_DECL(void) pjmedia_rtcp_build_rtcp( pjmedia_rtcp_session *session,
 
 
 /**
+ * Call this function if RTCP XR needs to be enabled/disabled in the 
+ * RTCP session.
+ *
+ * @param session   The RTCP session.
+ * @param enable    Enable/disable RTCP XR.
+ *
+ * @return	    PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_rtcp_enable_xr( pjmedia_rtcp_session *session, 
+					     pj_bool_t enable);
+
+
+/**
  * @}
  */
 
diff --git a/pjmedia/include/pjmedia/rtcp_xr.h b/pjmedia/include/pjmedia/rtcp_xr.h
new file mode 100644
index 00000000..d483366d
--- /dev/null
+++ b/pjmedia/include/pjmedia/rtcp_xr.h
@@ -0,0 +1,480 @@
+/* $Id$ */
+/* 
+ * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+ */
+#ifndef __PJMEDIA_RTCP_XR_H__
+#define __PJMEDIA_RTCP_XR_H__
+
+/**
+ * @file rtcp_xr.h
+ * @brief RTCP XR implementation.
+ */
+
+#include <pjmedia/types.h>
+
+
+PJ_BEGIN_DECL
+
+
+/**
+ * @defgroup PJMED_RTCP_XR RTCP Extended Report (XR) - RFC 3611
+ * @ingroup PJMEDIA_TRANSPORT
+ * @{
+ * PJMEDIA implements subsets of RTCP XR specification (RFC 3611) to monitor
+ * the quality of the real-time media (audio/video) transmission.
+ */
+
+/**
+ * Enumeration of report types of RTCP XR. Useful for user to enable varying
+ * combinations of RTCP XR report blocks.
+ */
+typedef enum {
+    PJMEDIA_RTCP_XR_LOSS_RLE	    = (1 << 0),
+    PJMEDIA_RTCP_XR_DUP_RLE	    = (1 << 1),
+    PJMEDIA_RTCP_XR_RCPT_TIMES	    = (1 << 2),
+    PJMEDIA_RTCP_XR_RR_TIME	    = (1 << 3),
+    PJMEDIA_RTCP_XR_DLRR	    = (1 << 4),
+    PJMEDIA_RTCP_XR_STATS	    = (1 << 5),
+    PJMEDIA_RTCP_XR_VOIP_METRICS    = (1 << 6)
+} pjmedia_rtcp_xr_type;
+
+/**
+ * Enumeration of info need to be updated manually to RTCP XR. Most info
+ * could be updated automatically each time RTP received.
+ */
+typedef enum {
+    PJMEDIA_RTCP_XR_INFO_SIGNAL_LVL = 1,
+    PJMEDIA_RTCP_XR_INFO_NOISE_LVL  = 2,
+    PJMEDIA_RTCP_XR_INFO_RERL	    = 3,
+    PJMEDIA_RTCP_XR_INFO_R_FACTOR   = 4,
+    PJMEDIA_RTCP_XR_INFO_MOS_LQ	    = 5,
+    PJMEDIA_RTCP_XR_INFO_MOS_CQ	    = 6,
+    PJMEDIA_RTCP_XR_INFO_CONF_PLC   = 7,
+    PJMEDIA_RTCP_XR_INFO_CONF_JBA   = 8,
+    PJMEDIA_RTCP_XR_INFO_CONF_JBR   = 9,
+    PJMEDIA_RTCP_XR_INFO_JB_NOM	    = 10,
+    PJMEDIA_RTCP_XR_INFO_JB_MAX	    = 11,
+    PJMEDIA_RTCP_XR_INFO_JB_ABS_MAX = 12
+} pjmedia_rtcp_xr_info;
+
+/**
+ * Enumeration of PLC types definitions for RTCP XR report.
+ */
+typedef enum {
+    PJMEDIA_RTCP_XR_PLC_UNK	    = 0,
+    PJMEDIA_RTCP_XR_PLC_DIS	    = 1,
+    PJMEDIA_RTCP_XR_PLC_ENH	    = 2,
+    PJMEDIA_RTCP_XR_PLC_STD	    = 3
+} pjmedia_rtcp_xr_plc_type;
+
+/**
+ * Enumeration of jitter buffer types definitions for RTCP XR report.
+ */
+typedef enum {
+    PJMEDIA_RTCP_XR_JB_UNKNOWN      = 0,
+    PJMEDIA_RTCP_XR_JB_FIXED        = 2,
+    PJMEDIA_RTCP_XR_JB_ADAPTIVE     = 3
+} pjmedia_rtcp_xr_jb_type;
+
+
+#pragma pack(1)
+
+/**
+ * This type declares RTCP XR Report Header.
+ */
+typedef struct pjmedia_rtcp_xr_rb_header
+{
+    pj_uint8_t		 bt;		/**< Block type.		*/
+    pj_uint8_t		 specific;	/**< Block specific data.	*/
+    pj_uint16_t		 length;	/**< Block length.		*/
+} pjmedia_rtcp_xr_rb_header;
+
+/**
+ * This type declares RTCP XR Receiver Reference Time Report Block.
+ */
+typedef struct pjmedia_rtcp_xr_rb_rr_time
+{
+    pjmedia_rtcp_xr_rb_header header;	/**< Block header.		*/
+    pj_uint32_t		 ntp_sec;	/**< NTP time, seconds part.	*/
+    pj_uint32_t		 ntp_frac;	/**< NTP time, fractions part.	*/
+} pjmedia_rtcp_xr_rb_rr_time;
+
+
+/**
+ * This type declares RTCP XR DLRR Report Sub-block
+ */
+typedef struct pjmedia_rtcp_xr_rb_dlrr_item
+{
+    pj_uint32_t		 ssrc;		/**< receiver SSRC		*/
+    pj_uint32_t		 lrr;		/**< last receiver report	*/
+    pj_uint32_t		 dlrr;		/**< delay since last receiver
+					     report			*/
+} pjmedia_rtcp_xr_rb_dlrr_item;
+
+/**
+ * This type declares RTCP XR DLRR Report Block
+ */
+typedef struct pjmedia_rtcp_xr_rb_dlrr
+{
+    pjmedia_rtcp_xr_rb_header header;	/**< Block header.		*/
+    pjmedia_rtcp_xr_rb_dlrr_item item;	/**< Block contents, 
+					     variable length list	*/
+} pjmedia_rtcp_xr_rb_dlrr;
+
+/**
+ * This type declares RTCP XR Statistics Summary Report Block
+ */
+typedef struct pjmedia_rtcp_xr_rb_stats
+{
+    pjmedia_rtcp_xr_rb_header header;	/**< Block header.		     */
+    pj_uint32_t		 ssrc;		/**< Receiver SSRC		     */
+    pj_uint16_t		 begin_seq;	/**< Begin RTP sequence reported     */
+    pj_uint16_t		 end_seq;	/**< End RTP sequence reported       */
+    pj_uint32_t		 lost;		/**< Number of packet lost in this 
+					     interval  */
+    pj_uint32_t		 dup;		/**< Number of duplicated packet in 
+					     this interval */
+    pj_uint32_t		 jitter_min;	/**< Minimum jitter in this interval */
+    pj_uint32_t		 jitter_max;	/**< Maximum jitter in this interval */
+    pj_uint32_t		 jitter_mean;	/**< Average jitter in this interval */
+    pj_uint32_t		 jitter_dev;	/**< Jitter deviation in this 
+					     interval */
+    pj_uint32_t		 toh_min:8;	/**< Minimum ToH in this interval    */
+    pj_uint32_t		 toh_max:8;	/**< Maximum ToH in this interval    */
+    pj_uint32_t		 toh_mean:8;	/**< Average ToH in this interval    */
+    pj_uint32_t		 toh_dev:8;	/**< ToH deviation in this interval  */
+} pjmedia_rtcp_xr_rb_stats;
+
+/**
+ * This type declares RTCP XR VoIP Metrics Report Block
+ */
+typedef struct pjmedia_rtcp_xr_rb_voip_mtc
+{
+    pjmedia_rtcp_xr_rb_header header;	/**< Block header.		*/
+    pj_uint32_t		 ssrc;		/**< Receiver SSRC		*/
+    pj_uint8_t		 loss_rate;	/**< Packet loss rate		*/
+    pj_uint8_t		 discard_rate;	/**< Packet discarded rate	*/
+    pj_uint8_t		 burst_den;	/**< Burst density		*/
+    pj_uint8_t		 gap_den;	/**< Gap density		*/
+    pj_uint16_t		 burst_dur;	/**< Burst duration		*/
+    pj_uint16_t		 gap_dur;	/**< Gap duration		*/
+    pj_uint16_t		 rnd_trip_delay;/**< Round trip delay		*/
+    pj_uint16_t		 end_sys_delay; /**< End system delay		*/
+    pj_uint8_t		 signal_lvl;	/**< Signal level		*/
+    pj_uint8_t		 noise_lvl;	/**< Noise level		*/
+    pj_uint8_t		 rerl;		/**< Residual Echo Return Loss	*/
+    pj_uint8_t		 gmin;		/**< The gap threshold		*/
+    pj_uint8_t		 r_factor;	/**< Voice quality metric carried
+					     over this RTP session	*/
+    pj_uint8_t		 ext_r_factor;  /**< Voice quality metric carried 
+					     outside of this RTP session*/
+    pj_uint8_t		 mos_lq;	/**< Mean Opinion Score for 
+					     Listening Quality          */
+    pj_uint8_t		 mos_cq;	/**< Mean Opinion Score for 
+					     Conversation Quality       */
+    pj_uint8_t		 rx_config;	/**< Receiver configuration	*/
+    pj_uint8_t		 reserved2;	/**< Not used			*/
+    pj_uint16_t		 jb_nom;	/**< Current delay by jitter
+					     buffer			*/
+    pj_uint16_t		 jb_max;	/**< Maximum delay by jitter
+					     buffer			*/
+    pj_uint16_t		 jb_abs_max;	/**< Maximum possible delay by
+					     jitter buffer		*/
+} pjmedia_rtcp_xr_rb_voip_mtc;
+
+/**
+ * This structure declares RTCP XR (Extended Report) packet.
+ */
+typedef struct pjmedia_rtcp_xr_pkt
+{
+    struct {
+#if defined(PJ_IS_BIG_ENDIAN) && PJ_IS_BIG_ENDIAN!=0
+	unsigned	 version:2;	/**< packet type            */
+	unsigned	 p:1;		/**< padding flag           */
+	unsigned	 count:5;	/**< varies by payload type */
+	unsigned	 pt:8;		/**< payload type           */
+#else
+	unsigned	 count:5;	/**< varies by payload type */
+	unsigned	 p:1;		/**< padding flag           */
+	unsigned	 version:2;	/**< packet type            */
+	unsigned	 pt:8;		/**< payload type           */
+#endif
+	unsigned	 length:16;	/**< packet length          */
+	pj_uint32_t	 ssrc;		/**< SSRC identification    */
+    } common;
+
+    pj_int8_t		 buf[PJMEDIA_MAX_MTU];/**< Content buffer   */
+} pjmedia_rtcp_xr_pkt;
+
+#pragma pack()
+
+
+/**
+ * This structure describes RTCP XR statitic.
+ */
+typedef struct pjmedia_rtcp_xr_stream_stat
+{
+    struct {
+	pj_uint32_t	    begin_seq;
+	pj_uint32_t	    end_seq;
+	unsigned	    count;	/**< Number of packets.		    */
+
+	/**
+	 * Flags represent whether the such report is valid/updated
+	 */
+	unsigned	    l:1;	/**< Lost flag			    */
+	unsigned	    d:1;	/**< Duplicated flag		    */
+	unsigned	    j:1;	/**< Jitter flag		    */
+	unsigned	    t:2;	/**< TTL or Hop Limit, 
+					     0=none, 1=TTL, 2=HL	    */
+
+	unsigned	    lost;	/**< Number of packets lost	    */
+	unsigned	    dup;	/**< Number of duplicated packets   */
+	
+	struct {
+	    unsigned	    min;	/**< Minimum jitter (in usec)	    */
+	    unsigned	    max;	/**< Maximum jitter (in usec)	    */
+	    unsigned	    dev;	/**< Jitter deviation (in usec)	    */
+	    unsigned	    mean;	/**< Average jitter (in usec)	    */
+	    unsigned	    count;	/**< Update count		    */
+	} jitter;			/**< Jitter history.		    */
+
+	struct {
+	    unsigned	    min;	/**< Minimum ToH		    */
+	    unsigned	    max;	/**< Maximum ToH		    */
+	    unsigned	    dev;	/**< ToH deviation		    */
+	    unsigned	    mean;	/**< Average ToH		    */
+	    unsigned	    count;	/**< Update count		    */
+	} toh;				/**< TTL of hop limit history.	    */
+    } stat_sum;
+
+    struct {
+	pj_uint8_t	    loss_rate;	    /**< Packet loss rate	    */
+	pj_uint8_t	    discard_rate;   /**< Packet discarded rate	    */
+	pj_uint8_t	    burst_den;	    /**< Burst density		    */
+	pj_uint8_t	    gap_den;	    /**< Gap density		    */
+	pj_uint16_t	    burst_dur;	    /**< Burst duration		    */
+	pj_uint16_t	    gap_dur;	    /**< Gap duration		    */
+	pj_uint16_t	    rnd_trip_delay; /**< Round trip delay	    */
+	pj_uint16_t	    end_sys_delay;  /**< End system delay	    */
+	pj_uint8_t	    signal_lvl;	    /**< Signal level		    */
+	pj_uint8_t	    noise_lvl;	    /**< Noise level		    */
+	pj_uint8_t	    rerl;	    /**< Residual Echo Return Loss  */
+	pj_uint8_t	    gmin;	    /**< The gap threshold	    */
+	pj_uint8_t	    r_factor;	    /**< Voice quality metric carried
+						 over this RTP session	    */
+	pj_uint8_t	    ext_r_factor;   /**< Voice quality metric carried 
+						 outside of this RTP session*/
+	pj_uint8_t	    mos_lq;	    /**< Mean Opinion Score for 
+						 Listening Quality          */
+	pj_uint8_t	    mos_cq;	    /**< Mean Opinion Score for 
+						 Conversation Quality       */
+	pj_uint8_t	    rx_config;	    /**< Receiver configuration	    */
+	pj_uint16_t	    jb_nom;	    /**< Current delay by jitter
+						 buffer			    */
+	pj_uint16_t	    jb_max;	    /**< Maximum delay by jitter
+						 buffer			    */
+	pj_uint16_t	    jb_abs_max;	    /**< Maximum possible delay by
+						 jitter buffer		    */
+    } voip_mtc;
+
+} pjmedia_rtcp_xr_stream_stat;
+
+typedef struct pjmedia_rtcp_xr_stat
+{
+    pjmedia_rtcp_xr_stream_stat	 rx;
+    pjmedia_rtcp_xr_stream_stat	 tx;
+
+    /* RTT calculated from receiver side */
+    struct {
+	unsigned    min;	    /**< Minimum round-trip delay (in usec) */
+	unsigned    avg;	    /**< Average round-trip delay (in usec) */
+	unsigned    max;	    /**< Maximum round-trip delay (in usec) */
+	unsigned    last;	    /**< Last round-trip delay (in usec)    */
+	unsigned    update_cnt;	    /**< Nb of times rtt is updated.	    */
+    } rtt;			    /**< Round trip delay history.	    */
+
+} pjmedia_rtcp_xr_stat;
+
+/**
+ * Forward declaration of RTCP session
+ */
+struct pjmedia_rtcp_session;
+
+/**
+ * RTCP session is used to monitor the RTP session of one endpoint. There
+ * should only be one RTCP session for a bidirectional RTP streams.
+ */
+struct pjmedia_rtcp_xr_session
+{
+    char		   *name;	/**< Name identification.	    */
+    pjmedia_rtcp_xr_pkt	    pkt;	/**< Cached RTCP XR packet.	    */
+
+    pj_uint32_t		    rx_lrr;	/**< NTP ts in last RR received.    */
+    pj_timestamp	    rx_lrr_time;/**< Time when last RR is received. */
+    pj_uint32_t		    rx_last_rr; /**< # pkt received since last 
+				             sending RR time.		    */
+
+    pjmedia_rtcp_xr_stat    stat;	/**< RTCP XR statistics.	    */
+
+    /* The reference sequence number is an extended sequence number
+     * that serves as the basis for determining whether a new 16 bit
+     * sequence number comes earlier or later in the 32 bit sequence
+     * space.
+     */
+    pj_uint32_t		    src_ref_seq;
+    pj_bool_t		    uninitialized_src_ref_seq;
+
+    /* This structure contains variables needed for calculating 
+     * burst metrics.
+     */
+    struct {
+	pj_uint32_t	    pkt;
+	pj_uint32_t	    lost;
+	pj_uint32_t	    loss_count;
+	pj_uint32_t	    discard_count;
+	pj_uint32_t	    c11;
+	pj_uint32_t	    c13;
+	pj_uint32_t	    c14;
+	pj_uint32_t	    c22;
+	pj_uint32_t	    c23;
+	pj_uint32_t	    c33;
+    } voip_mtc_stat;
+
+    unsigned ptime;			/**< Packet time.		    */
+    unsigned frames_per_packet;		/**< # frames per packet.	    */
+
+    struct pjmedia_rtcp_session *rtcp_session;
+					/**< Parent/RTCP session.	    */
+};
+
+typedef struct pjmedia_rtcp_xr_session pjmedia_rtcp_xr_session;
+
+/**
+ * Build an RTCP XR packet which contains one or more RTCP XR report blocks.
+ * There are seven report types as defined in RFC 3611.
+ *
+ * @param session   The RTCP XR session.
+ * @param rpt_types Report types to be included in the packet, report types
+ *		    are defined in pjmedia_rtcp_xr_type, set this to zero
+ *		    will make this function build all reports appropriately.
+ * @param rtcp_pkt  Upon return, it will contain pointer to the RTCP XR packet.
+ * @param len	    Upon return, it will indicate the size of the generated 
+ *		    RTCP XR packet.
+ */
+PJ_DECL(void) pjmedia_rtcp_build_rtcp_xr( pjmedia_rtcp_xr_session *session,
+					  unsigned rpt_types,
+					  void **rtcp_pkt, int *len);
+
+/**
+ * Call this function to manually update some info needed by RTCP XR to 
+ * generate report which could not be populated directly when receiving
+ * RTP.
+ *
+ * @param session   The RTCP XR session.
+ * @param info	    Info type to be updated, @see pjmedia_rtcp_xr_info.
+ * @param val	    Value.
+ */
+PJ_DECL(pj_status_t) pjmedia_rtcp_xr_update_info(
+					  pjmedia_rtcp_xr_session *session,
+					  unsigned info,
+					  pj_int32_t val);
+
+/*
+ * Private APIs:
+ */
+
+/**
+ * This function is called internally by RTCP session when RTCP XR is enabled
+ * to initialize the RTCP XR session.
+ *
+ * @param session   RTCP XR session.
+ * @param r_session RTCP session.
+ * @param gmin      Gmin value (defined in RFC 3611), set to 0 for default (16).
+ * @param ptime	    Packet time.
+ * @param frames_per_packet
+		    Number of frames per packet.
+ */
+void pjmedia_rtcp_xr_init( pjmedia_rtcp_xr_session *session, 
+			   struct pjmedia_rtcp_session *r_session,
+			   pj_uint8_t gmin,
+			   unsigned frames_per_packet);
+
+/**
+ * This function is called internally by RTCP session to destroy 
+ * the RTCP XR session.
+ *
+ * @param session   RTCP XR session.
+ */
+void pjmedia_rtcp_xr_fini( pjmedia_rtcp_xr_session *session );
+
+/**
+ * This function is called internally by RTCP session when it receives 
+ * incoming RTCP XR packets.
+ *
+ * @param session   RTCP XR session.
+ * @param rtcp_pkt  The received RTCP XR packet.
+ * @param size	    Size of the incoming packet.
+ */
+void pjmedia_rtcp_xr_rx_rtcp_xr( pjmedia_rtcp_xr_session *session,
+				 const void *rtcp_xr_pkt,
+				 pj_size_t size);
+
+/**
+ * This function is called internally by RTCP session whenever an RTP packet
+ * is received or lost to let the RTCP XR session update its statistics.
+ * Data passed to this function is a result of analyzation by RTCP and the
+ * jitter buffer. Whenever some info is available, the value should be zero
+ * or more (no negative info), otherwise if info is not available the info
+ * should be -1 so no update will be done for this info in the RTCP XR session.
+ *
+ * @param session   RTCP XR session.
+ * @param seq	    Sequence number of RTP packet.
+ * @param lost	    Info if this packet is lost. 
+ * @param dup	    Info if this packet is a duplication. 
+ * @param discarded Info if this packet is discarded 
+ *		    (not because of duplication).
+ * @param jitter    Info jitter of this packet.
+ * @param toh	    Info Time To Live or Hops Limit of this packet.
+ * @param toh_ipv4  Set PJ_TRUE if packet is transported over IPv4.
+ */
+void pjmedia_rtcp_xr_rx_rtp( pjmedia_rtcp_xr_session *session,
+			     unsigned seq, 
+			     int lost,
+			     int dup,
+			     int discarded,
+			     int jitter,
+			     int toh, pj_bool_t toh_ipv4);
+
+/**
+ * This function is called internally by RTCP session whenever an RTP 
+ * packet is sent to let the RTCP XR session do its internal calculations.
+ *
+ * @param session   RTCP XR session.
+ * @param ptsize    Size of RTP payload being sent.
+ */
+void pjmedia_rtcp_xr_tx_rtp( pjmedia_rtcp_xr_session *session, 
+			     unsigned ptsize );
+
+/**
+ * @}
+ */
+
+PJ_END_DECL
+
+
+#endif	/* __PJMEDIA_RTCP_XR_H__ */