• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 /**
21  * SECTION:element-rtpL16depay
22  * @title: rtpL16depay
23  * @see_also: rtpL16pay
24  *
25  * Extract raw audio from RTP packets according to RFC 3551.
26  * For detailed information see: http://www.rfc-editor.org/rfc/rfc3551.txt
27  *
28  * ## Example pipeline
29  * |[
30  * gst-launch-1.0 udpsrc caps='application/x-rtp, media=(string)audio, clock-rate=(int)44100, encoding-name=(string)L16, encoding-params=(string)1, channels=(int)1, payload=(int)96' ! rtpL16depay ! pulsesink
31  * ]| This example pipeline will depayload an RTP raw audio stream. Refer to
32  * the rtpL16pay example to create the RTP stream.
33  *
34  */
35 
36 #ifdef HAVE_CONFIG_H
37 #include "config.h"
38 #endif
39 
40 #include <string.h>
41 #include <stdlib.h>
42 
43 #include <gst/audio/audio.h>
44 
45 #include "gstrtpelements.h"
46 #include "gstrtpL16depay.h"
47 #include "gstrtpchannels.h"
48 #include "gstrtputils.h"
49 
50 GST_DEBUG_CATEGORY_STATIC (rtpL16depay_debug);
51 #define GST_CAT_DEFAULT (rtpL16depay_debug)
52 
53 static GstStaticPadTemplate gst_rtp_L16_depay_src_template =
54 GST_STATIC_PAD_TEMPLATE ("src",
55     GST_PAD_SRC,
56     GST_PAD_ALWAYS,
57     GST_STATIC_CAPS ("audio/x-raw, "
58         "format = (string) S16BE, "
59         "layout = (string) interleaved, "
60         "rate = (int) [ 1, MAX ], " "channels = (int) [ 1, MAX ]")
61     );
62 
63 static GstStaticPadTemplate gst_rtp_L16_depay_sink_template =
64     GST_STATIC_PAD_TEMPLATE ("sink",
65     GST_PAD_SINK,
66     GST_PAD_ALWAYS,
67     GST_STATIC_CAPS ("application/x-rtp, "
68         "media = (string) \"audio\", " "clock-rate = (int) [ 1, MAX ], "
69         /* "channels = (int) [1, MAX]"  */
70         /* "emphasis = (string) ANY" */
71         /* "channel-order = (string) ANY" */
72         "encoding-name = (string) \"L16\";"
73         "application/x-rtp, "
74         "media = (string) \"audio\", "
75         "payload = (int) { " GST_RTP_PAYLOAD_L16_STEREO_STRING ", "
76         GST_RTP_PAYLOAD_L16_MONO_STRING " }," "clock-rate = (int) [ 1, MAX ]"
77         /* "channels = (int) [1, MAX]" */
78         /* "emphasis = (string) ANY" */
79         /* "channel-order = (string) ANY" */
80     )
81     );
82 
83 #define gst_rtp_L16_depay_parent_class parent_class
84 G_DEFINE_TYPE (GstRtpL16Depay, gst_rtp_L16_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
85 GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (rtpL16depay, "rtpL16depay",
86     GST_RANK_SECONDARY, GST_TYPE_RTP_L16_DEPAY, rtp_element_init (plugin));
87 
88 static gboolean gst_rtp_L16_depay_setcaps (GstRTPBaseDepayload * depayload,
89     GstCaps * caps);
90 static GstBuffer *gst_rtp_L16_depay_process (GstRTPBaseDepayload * depayload,
91     GstRTPBuffer * rtp);
92 
93 static void
gst_rtp_L16_depay_class_init(GstRtpL16DepayClass * klass)94 gst_rtp_L16_depay_class_init (GstRtpL16DepayClass * klass)
95 {
96   GstElementClass *gstelement_class;
97   GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
98 
99   gstelement_class = (GstElementClass *) klass;
100   gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
101 
102   gstrtpbasedepayload_class->set_caps = gst_rtp_L16_depay_setcaps;
103   gstrtpbasedepayload_class->process_rtp_packet = gst_rtp_L16_depay_process;
104 
105   gst_element_class_add_static_pad_template (gstelement_class,
106       &gst_rtp_L16_depay_src_template);
107   gst_element_class_add_static_pad_template (gstelement_class,
108       &gst_rtp_L16_depay_sink_template);
109 
110   gst_element_class_set_static_metadata (gstelement_class,
111       "RTP audio depayloader", "Codec/Depayloader/Network/RTP",
112       "Extracts raw audio from RTP packets",
113       "Zeeshan Ali <zak147@yahoo.com>," "Wim Taymans <wim.taymans@gmail.com>");
114 
115   GST_DEBUG_CATEGORY_INIT (rtpL16depay_debug, "rtpL16depay", 0,
116       "Raw Audio RTP Depayloader");
117 }
118 
119 static void
gst_rtp_L16_depay_init(GstRtpL16Depay * rtpL16depay)120 gst_rtp_L16_depay_init (GstRtpL16Depay * rtpL16depay)
121 {
122 }
123 
124 static gint
gst_rtp_L16_depay_parse_int(GstStructure * structure,const gchar * field,gint def)125 gst_rtp_L16_depay_parse_int (GstStructure * structure, const gchar * field,
126     gint def)
127 {
128   const gchar *str;
129   gint res;
130 
131   if ((str = gst_structure_get_string (structure, field)))
132     return atoi (str);
133 
134   if (gst_structure_get_int (structure, field, &res))
135     return res;
136 
137   return def;
138 }
139 
140 static gboolean
gst_rtp_L16_depay_setcaps(GstRTPBaseDepayload * depayload,GstCaps * caps)141 gst_rtp_L16_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
142 {
143   GstStructure *structure;
144   GstRtpL16Depay *rtpL16depay;
145   gint clock_rate, payload;
146   gint channels;
147   GstCaps *srccaps;
148   gboolean res;
149   const gchar *channel_order;
150   const GstRTPChannelOrder *order;
151   GstAudioInfo *info;
152 
153   rtpL16depay = GST_RTP_L16_DEPAY (depayload);
154 
155   structure = gst_caps_get_structure (caps, 0);
156 
157   payload = 96;
158   gst_structure_get_int (structure, "payload", &payload);
159   switch (payload) {
160     case GST_RTP_PAYLOAD_L16_STEREO:
161       channels = 2;
162       clock_rate = 44100;
163       break;
164     case GST_RTP_PAYLOAD_L16_MONO:
165       channels = 1;
166       clock_rate = 44100;
167       break;
168     default:
169       /* no fixed mapping, we need clock-rate */
170       channels = 0;
171       clock_rate = 0;
172       break;
173   }
174 
175   /* caps can overwrite defaults */
176   clock_rate =
177       gst_rtp_L16_depay_parse_int (structure, "clock-rate", clock_rate);
178   if (clock_rate == 0)
179     goto no_clockrate;
180 
181   channels =
182       gst_rtp_L16_depay_parse_int (structure, "encoding-params", channels);
183   if (channels == 0) {
184     channels = gst_rtp_L16_depay_parse_int (structure, "channels", channels);
185     if (channels == 0) {
186       /* channels defaults to 1 otherwise */
187       channels = 1;
188     }
189   }
190 
191   depayload->clock_rate = clock_rate;
192 
193   info = &rtpL16depay->info;
194   gst_audio_info_init (info);
195   info->finfo = gst_audio_format_get_info (GST_AUDIO_FORMAT_S16BE);
196   info->rate = clock_rate;
197   info->channels = channels;
198   info->bpf = (info->finfo->width / 8) * channels;
199 
200   /* add channel positions */
201   channel_order = gst_structure_get_string (structure, "channel-order");
202 
203   order = gst_rtp_channels_get_by_order (channels, channel_order);
204   rtpL16depay->order = order;
205   if (order) {
206     memcpy (info->position, order->pos,
207         sizeof (GstAudioChannelPosition) * channels);
208     gst_audio_channel_positions_to_valid_order (info->position, info->channels);
209   } else {
210     GST_ELEMENT_WARNING (rtpL16depay, STREAM, DECODE,
211         (NULL), ("Unknown channel order '%s' for %d channels",
212             GST_STR_NULL (channel_order), channels));
213     /* create default NONE layout */
214     gst_rtp_channels_create_default (channels, info->position);
215     info->flags |= GST_AUDIO_FLAG_UNPOSITIONED;
216   }
217 
218   srccaps = gst_audio_info_to_caps (info);
219   res = gst_pad_set_caps (depayload->srcpad, srccaps);
220   gst_caps_unref (srccaps);
221 
222   return res;
223 
224   /* ERRORS */
225 no_clockrate:
226   {
227     GST_ERROR_OBJECT (depayload, "no clock-rate specified");
228     return FALSE;
229   }
230 }
231 
232 static GstBuffer *
gst_rtp_L16_depay_process(GstRTPBaseDepayload * depayload,GstRTPBuffer * rtp)233 gst_rtp_L16_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)
234 {
235   GstRtpL16Depay *rtpL16depay;
236   GstBuffer *outbuf;
237   gint payload_len;
238   gboolean marker;
239   GstAudioInfo *info;
240 
241   rtpL16depay = GST_RTP_L16_DEPAY (depayload);
242 
243   payload_len = gst_rtp_buffer_get_payload_len (rtp);
244 
245   if (payload_len <= 0)
246     goto empty_packet;
247 
248   GST_DEBUG_OBJECT (rtpL16depay, "got payload of %d bytes", payload_len);
249 
250   outbuf = gst_rtp_buffer_get_payload_buffer (rtp);
251   marker = gst_rtp_buffer_get_marker (rtp);
252 
253   if (marker) {
254     /* mark talk spurt with RESYNC */
255     GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_RESYNC);
256   }
257 
258   outbuf = gst_buffer_make_writable (outbuf);
259   info = &rtpL16depay->info;
260 
261   if (payload_len % info->bpf != 0)
262     goto wrong_payload_size;
263 
264   if (rtpL16depay->order &&
265       !gst_audio_buffer_reorder_channels (outbuf,
266           info->finfo->format, info->channels,
267           info->position, rtpL16depay->order->pos)) {
268     goto reorder_failed;
269   }
270 
271   gst_rtp_drop_non_audio_meta (rtpL16depay, outbuf);
272 
273   return outbuf;
274 
275   /* ERRORS */
276 empty_packet:
277   {
278     GST_ELEMENT_WARNING (rtpL16depay, STREAM, DECODE,
279         ("Empty Payload."), (NULL));
280     return NULL;
281   }
282 wrong_payload_size:
283   {
284     GST_ELEMENT_WARNING (rtpL16depay, STREAM, DECODE,
285         ("Wrong Payload Size."), (NULL));
286     gst_buffer_unref (outbuf);
287     return NULL;
288   }
289 reorder_failed:
290   {
291     GST_ELEMENT_ERROR (rtpL16depay, STREAM, DECODE,
292         ("Channel reordering failed."), (NULL));
293     gst_buffer_unref (outbuf);
294     return NULL;
295   }
296 }
297