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 #ifdef HAVE_CONFIG_H
21 #include "config.h"
22 #endif
23 
24 #include <string.h>
25 #include <stdlib.h>
26 
27 #include <gst/audio/audio.h>
28 
29 #include "gstrtpg722depay.h"
30 #include "gstrtpchannels.h"
31 #include "gstrtputils.h"
32 
33 GST_DEBUG_CATEGORY_STATIC (rtpg722depay_debug);
34 #define GST_CAT_DEFAULT (rtpg722depay_debug)
35 
36 static GstStaticPadTemplate gst_rtp_g722_depay_src_template =
37 GST_STATIC_PAD_TEMPLATE ("src",
38     GST_PAD_SRC,
39     GST_PAD_ALWAYS,
40     GST_STATIC_CAPS ("audio/G722, "
41         "rate = (int) [ 1, MAX ], " "channels = (int) [ 1, MAX ]")
42     );
43 
44 static GstStaticPadTemplate gst_rtp_g722_depay_sink_template =
45     GST_STATIC_PAD_TEMPLATE ("sink",
46     GST_PAD_SINK,
47     GST_PAD_ALWAYS,
48     GST_STATIC_CAPS ("application/x-rtp, "
49         "media = (string) \"audio\", " "clock-rate = (int) 8000, "
50         /* "channels = (int) [1, MAX]"  */
51         /* "channel-order = (string) ANY" */
52         "encoding-name = (string) \"G722\";"
53         "application/x-rtp, "
54         "media = (string) \"audio\", "
55         "payload = (int) " GST_RTP_PAYLOAD_G722_STRING ", "
56         "clock-rate = (int) [ 1, MAX ]"
57         /* "channels = (int) [1, MAX]" */
58         /* "emphasis = (string) ANY" */
59         /* "channel-order = (string) ANY" */
60     )
61     );
62 
63 #define gst_rtp_g722_depay_parent_class parent_class
64 G_DEFINE_TYPE (GstRtpG722Depay, gst_rtp_g722_depay,
65     GST_TYPE_RTP_BASE_DEPAYLOAD);
66 
67 static gboolean gst_rtp_g722_depay_setcaps (GstRTPBaseDepayload * depayload,
68     GstCaps * caps);
69 static GstBuffer *gst_rtp_g722_depay_process (GstRTPBaseDepayload * depayload,
70     GstRTPBuffer * rtp);
71 
72 static void
gst_rtp_g722_depay_class_init(GstRtpG722DepayClass * klass)73 gst_rtp_g722_depay_class_init (GstRtpG722DepayClass * klass)
74 {
75   GstElementClass *gstelement_class;
76   GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
77 
78   GST_DEBUG_CATEGORY_INIT (rtpg722depay_debug, "rtpg722depay", 0,
79       "G722 RTP Depayloader");
80 
81   gstelement_class = (GstElementClass *) klass;
82   gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
83 
84   gst_element_class_add_static_pad_template (gstelement_class,
85       &gst_rtp_g722_depay_src_template);
86   gst_element_class_add_static_pad_template (gstelement_class,
87       &gst_rtp_g722_depay_sink_template);
88 
89   gst_element_class_set_static_metadata (gstelement_class,
90       "RTP audio depayloader", "Codec/Depayloader/Network/RTP",
91       "Extracts G722 audio from RTP packets",
92       "Wim Taymans <wim.taymans@gmail.com>");
93 
94   gstrtpbasedepayload_class->set_caps = gst_rtp_g722_depay_setcaps;
95   gstrtpbasedepayload_class->process_rtp_packet = gst_rtp_g722_depay_process;
96 }
97 
98 static void
gst_rtp_g722_depay_init(GstRtpG722Depay * rtpg722depay)99 gst_rtp_g722_depay_init (GstRtpG722Depay * rtpg722depay)
100 {
101 }
102 
103 static gint
gst_rtp_g722_depay_parse_int(GstStructure * structure,const gchar * field,gint def)104 gst_rtp_g722_depay_parse_int (GstStructure * structure, const gchar * field,
105     gint def)
106 {
107   const gchar *str;
108   gint res;
109 
110   if ((str = gst_structure_get_string (structure, field)))
111     return atoi (str);
112 
113   if (gst_structure_get_int (structure, field, &res))
114     return res;
115 
116   return def;
117 }
118 
119 static gboolean
gst_rtp_g722_depay_setcaps(GstRTPBaseDepayload * depayload,GstCaps * caps)120 gst_rtp_g722_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
121 {
122   GstStructure *structure;
123   GstRtpG722Depay *rtpg722depay;
124   gint clock_rate, payload, samplerate;
125   gint channels;
126   GstCaps *srccaps;
127   gboolean res;
128 #if 0
129   const gchar *channel_order;
130   const GstRTPChannelOrder *order;
131 #endif
132 
133   rtpg722depay = GST_RTP_G722_DEPAY (depayload);
134 
135   structure = gst_caps_get_structure (caps, 0);
136 
137   payload = 96;
138   gst_structure_get_int (structure, "payload", &payload);
139   switch (payload) {
140     case GST_RTP_PAYLOAD_G722:
141       channels = 1;
142       clock_rate = 8000;
143       samplerate = 16000;
144       break;
145     default:
146       /* no fixed mapping, we need clock-rate */
147       channels = 0;
148       clock_rate = 0;
149       samplerate = 0;
150       break;
151   }
152 
153   /* caps can overwrite defaults */
154   clock_rate =
155       gst_rtp_g722_depay_parse_int (structure, "clock-rate", clock_rate);
156   if (clock_rate == 0)
157     goto no_clockrate;
158 
159   if (clock_rate == 8000)
160     samplerate = 16000;
161 
162   if (samplerate == 0)
163     samplerate = clock_rate;
164 
165   channels =
166       gst_rtp_g722_depay_parse_int (structure, "encoding-params", channels);
167   if (channels == 0) {
168     channels = gst_rtp_g722_depay_parse_int (structure, "channels", channels);
169     if (channels == 0) {
170       /* channels defaults to 1 otherwise */
171       channels = 1;
172     }
173   }
174 
175   depayload->clock_rate = clock_rate;
176   rtpg722depay->rate = samplerate;
177   rtpg722depay->channels = channels;
178 
179   srccaps = gst_caps_new_simple ("audio/G722",
180       "rate", G_TYPE_INT, samplerate, "channels", G_TYPE_INT, channels, NULL);
181 
182   /* FIXME: Do something with the channel order */
183 #if 0
184   /* add channel positions */
185   channel_order = gst_structure_get_string (structure, "channel-order");
186 
187   order = gst_rtp_channels_get_by_order (channels, channel_order);
188   if (order) {
189     gst_audio_set_channel_positions (gst_caps_get_structure (srccaps, 0),
190         order->pos);
191   } else {
192     GstAudioChannelPosition *pos;
193 
194     GST_ELEMENT_WARNING (rtpg722depay, STREAM, DECODE,
195         (NULL), ("Unknown channel order '%s' for %d channels",
196             GST_STR_NULL (channel_order), channels));
197     /* create default NONE layout */
198     pos = gst_rtp_channels_create_default (channels);
199     gst_audio_set_channel_positions (gst_caps_get_structure (srccaps, 0), pos);
200     g_free (pos);
201   }
202 #endif
203 
204   res = gst_pad_set_caps (depayload->srcpad, srccaps);
205   gst_caps_unref (srccaps);
206 
207   return res;
208 
209   /* ERRORS */
210 no_clockrate:
211   {
212     GST_ERROR_OBJECT (depayload, "no clock-rate specified");
213     return FALSE;
214   }
215 }
216 
217 static GstBuffer *
gst_rtp_g722_depay_process(GstRTPBaseDepayload * depayload,GstRTPBuffer * rtp)218 gst_rtp_g722_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)
219 {
220   GstRtpG722Depay *rtpg722depay;
221   GstBuffer *outbuf;
222   gint payload_len;
223   gboolean marker;
224 
225   rtpg722depay = GST_RTP_G722_DEPAY (depayload);
226 
227   payload_len = gst_rtp_buffer_get_payload_len (rtp);
228 
229   if (payload_len <= 0)
230     goto empty_packet;
231 
232   GST_DEBUG_OBJECT (rtpg722depay, "got payload of %d bytes", payload_len);
233 
234   outbuf = gst_rtp_buffer_get_payload_buffer (rtp);
235   marker = gst_rtp_buffer_get_marker (rtp);
236 
237   if (marker && outbuf) {
238     /* mark talk spurt with RESYNC */
239     GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_RESYNC);
240   }
241 
242   if (outbuf) {
243     gst_rtp_drop_non_audio_meta (rtpg722depay, outbuf);
244   }
245 
246   return outbuf;
247 
248   /* ERRORS */
249 empty_packet:
250   {
251     GST_ELEMENT_WARNING (rtpg722depay, STREAM, DECODE,
252         ("Empty Payload."), (NULL));
253     return NULL;
254   }
255 }
256 
257 gboolean
gst_rtp_g722_depay_plugin_init(GstPlugin * plugin)258 gst_rtp_g722_depay_plugin_init (GstPlugin * plugin)
259 {
260   return gst_element_register (plugin, "rtpg722depay",
261       GST_RANK_SECONDARY, GST_TYPE_RTP_G722_DEPAY);
262 }
263