1 /* GStreamer
2  * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
3  * Copyright (C) <2005> Zeeshan Ali <zeenix@gmail.com>
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Library General Public
7  * License as published by the Free Software Foundation; either
8  * version 2 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Library General Public License for more details.
14  *
15  * You should have received a copy of the GNU Library General Public
16  * License along with this library; if not, write to the
17  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18  * Boston, MA 02110-1301, USA.
19  */
20 
21 #ifdef HAVE_CONFIG_H
22 #  include "config.h"
23 #endif
24 
25 #include <string.h>
26 #include <gst/rtp/gstrtpbuffer.h>
27 #include <gst/audio/audio.h>
28 #include "gstrtpgsmdepay.h"
29 #include "gstrtputils.h"
30 
31 GST_DEBUG_CATEGORY_STATIC (rtpgsmdepay_debug);
32 #define GST_CAT_DEFAULT (rtpgsmdepay_debug)
33 
34 /* RTPGSMDepay signals and args */
35 enum
36 {
37   /* FILL ME */
38   LAST_SIGNAL
39 };
40 
41 static GstStaticPadTemplate gst_rtp_gsm_depay_src_template =
42 GST_STATIC_PAD_TEMPLATE ("src",
43     GST_PAD_SRC,
44     GST_PAD_ALWAYS,
45     GST_STATIC_CAPS ("audio/x-gsm, " "rate = (int) 8000, " "channels = 1")
46     );
47 
48 static GstStaticPadTemplate gst_rtp_gsm_depay_sink_template =
49     GST_STATIC_PAD_TEMPLATE ("sink",
50     GST_PAD_SINK,
51     GST_PAD_ALWAYS,
52     GST_STATIC_CAPS ("application/x-rtp, "
53         "media = (string) \"audio\", "
54         "clock-rate = (int) 8000, " "encoding-name = (string) \"GSM\";"
55         "application/x-rtp, "
56         "media = (string) \"audio\", "
57         "payload = (int) " GST_RTP_PAYLOAD_GSM_STRING ", "
58         "clock-rate = (int) 8000")
59     );
60 
61 static GstBuffer *gst_rtp_gsm_depay_process (GstRTPBaseDepayload * _depayload,
62     GstRTPBuffer * rtp);
63 static gboolean gst_rtp_gsm_depay_setcaps (GstRTPBaseDepayload * _depayload,
64     GstCaps * caps);
65 
66 #define gst_rtp_gsm_depay_parent_class parent_class
67 G_DEFINE_TYPE (GstRTPGSMDepay, gst_rtp_gsm_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
68 
69 static void
gst_rtp_gsm_depay_class_init(GstRTPGSMDepayClass * klass)70 gst_rtp_gsm_depay_class_init (GstRTPGSMDepayClass * klass)
71 {
72   GstElementClass *gstelement_class;
73   GstRTPBaseDepayloadClass *gstrtpbase_depayload_class;
74 
75   gstelement_class = (GstElementClass *) klass;
76   gstrtpbase_depayload_class = (GstRTPBaseDepayloadClass *) klass;
77 
78   gst_element_class_add_static_pad_template (gstelement_class,
79       &gst_rtp_gsm_depay_src_template);
80   gst_element_class_add_static_pad_template (gstelement_class,
81       &gst_rtp_gsm_depay_sink_template);
82 
83   gst_element_class_set_static_metadata (gstelement_class,
84       "RTP GSM depayloader", "Codec/Depayloader/Network/RTP",
85       "Extracts GSM audio from RTP packets", "Zeeshan Ali <zeenix@gmail.com>");
86 
87   gstrtpbase_depayload_class->process_rtp_packet = gst_rtp_gsm_depay_process;
88   gstrtpbase_depayload_class->set_caps = gst_rtp_gsm_depay_setcaps;
89 
90   GST_DEBUG_CATEGORY_INIT (rtpgsmdepay_debug, "rtpgsmdepay", 0,
91       "GSM Audio RTP Depayloader");
92 }
93 
94 static void
gst_rtp_gsm_depay_init(GstRTPGSMDepay * rtpgsmdepay)95 gst_rtp_gsm_depay_init (GstRTPGSMDepay * rtpgsmdepay)
96 {
97 }
98 
99 static gboolean
gst_rtp_gsm_depay_setcaps(GstRTPBaseDepayload * depayload,GstCaps * caps)100 gst_rtp_gsm_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
101 {
102   GstCaps *srccaps;
103   gboolean ret;
104   GstStructure *structure;
105   gint clock_rate;
106 
107   structure = gst_caps_get_structure (caps, 0);
108 
109   if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
110     clock_rate = 8000;          /* default */
111   depayload->clock_rate = clock_rate;
112 
113   srccaps = gst_caps_new_simple ("audio/x-gsm",
114       "channels", G_TYPE_INT, 1, "rate", G_TYPE_INT, clock_rate, NULL);
115   ret = gst_pad_set_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (depayload), srccaps);
116   gst_caps_unref (srccaps);
117 
118   return ret;
119 }
120 
121 static GstBuffer *
gst_rtp_gsm_depay_process(GstRTPBaseDepayload * depayload,GstRTPBuffer * rtp)122 gst_rtp_gsm_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)
123 {
124   GstBuffer *outbuf = NULL;
125   gboolean marker;
126 
127   marker = gst_rtp_buffer_get_marker (rtp);
128 
129   GST_DEBUG ("process : got %" G_GSIZE_FORMAT " bytes, mark %d ts %u seqn %d",
130       gst_buffer_get_size (rtp->buffer), marker,
131       gst_rtp_buffer_get_timestamp (rtp), gst_rtp_buffer_get_seq (rtp));
132 
133   outbuf = gst_rtp_buffer_get_payload_buffer (rtp);
134 
135   if (marker && outbuf) {
136     /* mark start of talkspurt with RESYNC */
137     GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_RESYNC);
138   }
139 
140   if (outbuf) {
141     gst_rtp_drop_non_audio_meta (depayload, outbuf);
142   }
143 
144   return outbuf;
145 }
146 
147 gboolean
gst_rtp_gsm_depay_plugin_init(GstPlugin * plugin)148 gst_rtp_gsm_depay_plugin_init (GstPlugin * plugin)
149 {
150   return gst_element_register (plugin, "rtpgsmdepay",
151       GST_RANK_SECONDARY, GST_TYPE_RTP_GSM_DEPAY);
152 }
153