1 /* GStreamer
2  * Copyright (C) <2007> Wim Taymans <wim.taymans@gmail.com>
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Library General Public
6  * License as published by the Free Software Foundation; either
7  * version 2 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Library General Public License for more details.
13  *
14  * You should have received a copy of the GNU Library General Public
15  * License along with this library; if not, write to the
16  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
17  * Boston, MA 02110-1301, USA.
18  */
19 
20 #ifndef __RTP_JITTER_BUFFER_H__
21 #define __RTP_JITTER_BUFFER_H__
22 
23 #include <gst/gst.h>
24 #include <gst/rtp/gstrtcpbuffer.h>
25 
26 typedef struct _RTPJitterBuffer RTPJitterBuffer;
27 typedef struct _RTPJitterBufferClass RTPJitterBufferClass;
28 typedef struct _RTPJitterBufferItem RTPJitterBufferItem;
29 
30 #define RTP_TYPE_JITTER_BUFFER             (rtp_jitter_buffer_get_type())
31 #define RTP_JITTER_BUFFER(src)             (G_TYPE_CHECK_INSTANCE_CAST((src),RTP_TYPE_JITTER_BUFFER,RTPJitterBuffer))
32 #define RTP_JITTER_BUFFER_CLASS(klass)     (G_TYPE_CHECK_CLASS_CAST((klass),RTP_TYPE_JITTER_BUFFER,RTPJitterBufferClass))
33 #define RTP_IS_JITTER_BUFFER(src)          (G_TYPE_CHECK_INSTANCE_TYPE((src),RTP_TYPE_JITTER_BUFFER))
34 #define RTP_IS_JITTER_BUFFER_CLASS(klass)  (G_TYPE_CHECK_CLASS_TYPE((klass),RTP_TYPE_JITTER_BUFFER))
35 #define RTP_JITTER_BUFFER_CAST(src)        ((RTPJitterBuffer *)(src))
36 
37 /**
38  * RTPJitterBufferMode:
39  * @RTP_JITTER_BUFFER_MODE_NONE: don't do any skew correction, outgoing
40  *    timestamps are calculated directly from the RTP timestamps. This mode is
41  *    good for recording but not for real-time applications.
42  * @RTP_JITTER_BUFFER_MODE_SLAVE: calculate the skew between sender and receiver
43  *    and produce smoothed adjusted outgoing timestamps. This mode is good for
44  *    low latency communications.
45  * @RTP_JITTER_BUFFER_MODE_BUFFER: buffer packets between low/high watermarks.
46  *    This mode is good for streaming communication.
47  * @RTP_JITTER_BUFFER_MODE_SYNCED: sender and receiver clocks are synchronized,
48  *    like #RTP_JITTER_BUFFER_MODE_SLAVE but skew is assumed to be 0. Good for
49  *    low latency communication when sender and receiver clocks are
50  *    synchronized and there is thus no clock skew.
51  * @RTP_JITTER_BUFFER_MODE_LAST: last buffer mode.
52  *
53  * The different buffer modes for a jitterbuffer.
54  */
55 typedef enum {
56   RTP_JITTER_BUFFER_MODE_NONE    = 0,
57   RTP_JITTER_BUFFER_MODE_SLAVE   = 1,
58   RTP_JITTER_BUFFER_MODE_BUFFER  = 2,
59   /* FIXME 3 is missing because it was used for 'auto' in jitterbuffer */
60   RTP_JITTER_BUFFER_MODE_SYNCED  = 4,
61   RTP_JITTER_BUFFER_MODE_LAST
62 } RTPJitterBufferMode;
63 
64 #define RTP_TYPE_JITTER_BUFFER_MODE (rtp_jitter_buffer_mode_get_type())
65 GType rtp_jitter_buffer_mode_get_type (void);
66 
67 #define RTP_JITTER_BUFFER_MAX_WINDOW 512
68 /**
69  * RTPJitterBuffer:
70  *
71  * A JitterBuffer in the #RTPSession
72  */
73 struct _RTPJitterBuffer {
74   GObject        object;
75 
76   GQueue        *packets;
77 
78   RTPJitterBufferMode mode;
79 
80   GstClockTime   delay;
81 
82   /* for buffering */
83   gboolean          buffering;
84   guint64           low_level;
85   guint64           high_level;
86 
87   /* for calculating skew */
88   gboolean       need_resync;
89   GstClockTime   base_time;
90   GstClockTime   base_rtptime;
91   GstClockTime   media_clock_base_time;
92   guint32        clock_rate;
93   GstClockTime   base_extrtp;
94   GstClockTime   prev_out_time;
95   guint64        ext_rtptime;
96   guint64        last_rtptime;
97   gint64         window[RTP_JITTER_BUFFER_MAX_WINDOW];
98   guint          window_pos;
99   guint          window_size;
100   gboolean       window_filling;
101   gint64         window_min;
102   gint64         skew;
103   gint64         prev_send_diff;
104   gboolean       buffering_disabled;
105 
106   GMutex         clock_lock;
107   GstClock      *pipeline_clock;
108   GstClock      *media_clock;
109   gulong         media_clock_synced_id;
110   guint64        media_clock_offset;
111 
112   gboolean       rfc7273_sync;
113 };
114 
115 struct _RTPJitterBufferClass {
116   GObjectClass   parent_class;
117 };
118 
119 /**
120  * RTPJitterBufferItem:
121  * @data: the data of the item
122  * @next: pointer to next item
123  * @prev: pointer to previous item
124  * @type: the type of @data, used freely by caller
125  * @dts: input DTS
126  * @pts: output PTS
127  * @seqnum: seqnum, the seqnum is used to insert the item in the
128  *   right position in the jitterbuffer and detect duplicates. Use -1 to
129  *   append.
130  * @count: amount of seqnum in this item
131  * @rtptime: rtp timestamp
132  *
133  * An object containing an RTP packet or event.
134  */
135 struct _RTPJitterBufferItem {
136   gpointer data;
137   GList *next;
138   GList *prev;
139   guint type;
140   GstClockTime dts;
141   GstClockTime pts;
142   guint seqnum;
143   guint count;
144   guint rtptime;
145 };
146 
147 GType rtp_jitter_buffer_get_type (void);
148 
149 /* managing lifetime */
150 RTPJitterBuffer*      rtp_jitter_buffer_new              (void);
151 
152 RTPJitterBufferMode   rtp_jitter_buffer_get_mode         (RTPJitterBuffer *jbuf);
153 void                  rtp_jitter_buffer_set_mode         (RTPJitterBuffer *jbuf, RTPJitterBufferMode mode);
154 
155 GstClockTime          rtp_jitter_buffer_get_delay        (RTPJitterBuffer *jbuf);
156 void                  rtp_jitter_buffer_set_delay        (RTPJitterBuffer *jbuf, GstClockTime delay);
157 
158 void                  rtp_jitter_buffer_set_clock_rate   (RTPJitterBuffer *jbuf, guint32 clock_rate);
159 guint32               rtp_jitter_buffer_get_clock_rate   (RTPJitterBuffer *jbuf);
160 
161 void                  rtp_jitter_buffer_set_media_clock  (RTPJitterBuffer *jbuf, GstClock * clock, guint64 clock_offset);
162 void                  rtp_jitter_buffer_set_pipeline_clock (RTPJitterBuffer *jbuf, GstClock * clock);
163 
164 gboolean              rtp_jitter_buffer_get_rfc7273_sync (RTPJitterBuffer *jbuf);
165 void                  rtp_jitter_buffer_set_rfc7273_sync (RTPJitterBuffer *jbuf, gboolean rfc7273_sync);
166 
167 void                  rtp_jitter_buffer_reset_skew       (RTPJitterBuffer *jbuf);
168 
169 gboolean              rtp_jitter_buffer_insert           (RTPJitterBuffer *jbuf,
170                                                           RTPJitterBufferItem *item,
171                                                           gboolean *head, gint *percent);
172 
173 void                  rtp_jitter_buffer_disable_buffering (RTPJitterBuffer *jbuf, gboolean disabled);
174 
175 RTPJitterBufferItem * rtp_jitter_buffer_peek             (RTPJitterBuffer *jbuf);
176 RTPJitterBufferItem * rtp_jitter_buffer_pop              (RTPJitterBuffer *jbuf, gint *percent);
177 
178 void                  rtp_jitter_buffer_flush            (RTPJitterBuffer *jbuf,
179                                                           GFunc free_func, gpointer user_data);
180 
181 gboolean              rtp_jitter_buffer_is_buffering     (RTPJitterBuffer * jbuf);
182 void                  rtp_jitter_buffer_set_buffering    (RTPJitterBuffer * jbuf, gboolean buffering);
183 gint                  rtp_jitter_buffer_get_percent      (RTPJitterBuffer * jbuf);
184 
185 guint                 rtp_jitter_buffer_num_packets      (RTPJitterBuffer *jbuf);
186 guint32               rtp_jitter_buffer_get_ts_diff      (RTPJitterBuffer *jbuf);
187 guint16               rtp_jitter_buffer_get_seqnum_diff  (RTPJitterBuffer * jbuf);
188 
189 void                  rtp_jitter_buffer_get_sync         (RTPJitterBuffer *jbuf, guint64 *rtptime,
190                                                           guint64 *timestamp, guint32 *clock_rate,
191                                                           guint64 *last_rtptime);
192 
193 GstClockTime          rtp_jitter_buffer_calculate_pts    (RTPJitterBuffer * jbuf, GstClockTime dts, gboolean estimated_dts,
194                                                           guint32 rtptime, GstClockTime base_time);
195 
196 gboolean              rtp_jitter_buffer_can_fast_start   (RTPJitterBuffer * jbuf, gint num_packet);
197 
198 #endif /* __RTP_JITTER_BUFFER_H__ */
199