1 /* GStreamer
2 * Copyright (C) <2010> 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 <gst/rtp/gstrtpbuffer.h>
25 #include <gst/audio/audio.h>
26
27 #include <stdlib.h>
28 #include <string.h>
29 #include "gstrtpelements.h"
30 #include "gstrtpqcelpdepay.h"
31 #include "gstrtputils.h"
32
33 GST_DEBUG_CATEGORY_STATIC (rtpqcelpdepay_debug);
34 #define GST_CAT_DEFAULT (rtpqcelpdepay_debug)
35
36 /* references:
37 *
38 * RFC 2658 - RTP Payload Format for PureVoice(tm) Audio
39 */
40 #define FRAME_DURATION (20 * GST_MSECOND)
41
42 /* RtpQCELPDepay signals and args */
43 enum
44 {
45 /* FILL ME */
46 LAST_SIGNAL
47 };
48
49 enum
50 {
51 PROP_0
52 };
53
54 static GstStaticPadTemplate gst_rtp_qcelp_depay_sink_template =
55 GST_STATIC_PAD_TEMPLATE ("sink",
56 GST_PAD_SINK,
57 GST_PAD_ALWAYS,
58 GST_STATIC_CAPS ("application/x-rtp, "
59 "media = (string) \"audio\", "
60 "clock-rate = (int) 8000, "
61 "encoding-name = (string) \"QCELP\"; "
62 "application/x-rtp, "
63 "media = (string) \"audio\", "
64 "payload = (int) " GST_RTP_PAYLOAD_QCELP_STRING ", "
65 "clock-rate = (int) 8000")
66 );
67
68 static GstStaticPadTemplate gst_rtp_qcelp_depay_src_template =
69 GST_STATIC_PAD_TEMPLATE ("src",
70 GST_PAD_SRC,
71 GST_PAD_ALWAYS,
72 GST_STATIC_CAPS ("audio/qcelp, " "channels = (int) 1," "rate = (int) 8000")
73 );
74
75 static void gst_rtp_qcelp_depay_finalize (GObject * object);
76
77 static gboolean gst_rtp_qcelp_depay_setcaps (GstRTPBaseDepayload * depayload,
78 GstCaps * caps);
79 static GstBuffer *gst_rtp_qcelp_depay_process (GstRTPBaseDepayload * depayload,
80 GstRTPBuffer * rtp);
81
82 #define gst_rtp_qcelp_depay_parent_class parent_class
83 G_DEFINE_TYPE (GstRtpQCELPDepay, gst_rtp_qcelp_depay,
84 GST_TYPE_RTP_BASE_DEPAYLOAD);
85 GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (rtpqcelpdepay, "rtpqcelpdepay",
86 GST_RANK_SECONDARY, GST_TYPE_RTP_QCELP_DEPAY, rtp_element_init (plugin));
87
88 static void
gst_rtp_qcelp_depay_class_init(GstRtpQCELPDepayClass * klass)89 gst_rtp_qcelp_depay_class_init (GstRtpQCELPDepayClass * klass)
90 {
91 GObjectClass *gobject_class;
92 GstElementClass *gstelement_class;
93 GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
94
95 gobject_class = (GObjectClass *) klass;
96 gstelement_class = (GstElementClass *) klass;
97 gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
98
99 gobject_class->finalize = gst_rtp_qcelp_depay_finalize;
100
101 gstrtpbasedepayload_class->process_rtp_packet = gst_rtp_qcelp_depay_process;
102 gstrtpbasedepayload_class->set_caps = gst_rtp_qcelp_depay_setcaps;
103
104 gst_element_class_add_static_pad_template (gstelement_class,
105 &gst_rtp_qcelp_depay_src_template);
106 gst_element_class_add_static_pad_template (gstelement_class,
107 &gst_rtp_qcelp_depay_sink_template);
108
109 gst_element_class_set_static_metadata (gstelement_class,
110 "RTP QCELP depayloader", "Codec/Depayloader/Network/RTP",
111 "Extracts QCELP (PureVoice) audio from RTP packets (RFC 2658)",
112 "Wim Taymans <wim.taymans@gmail.com>");
113
114 GST_DEBUG_CATEGORY_INIT (rtpqcelpdepay_debug, "rtpqcelpdepay", 0,
115 "QCELP RTP Depayloader");
116 }
117
118 static void
gst_rtp_qcelp_depay_init(GstRtpQCELPDepay * rtpqcelpdepay)119 gst_rtp_qcelp_depay_init (GstRtpQCELPDepay * rtpqcelpdepay)
120 {
121 }
122
123 static void
gst_rtp_qcelp_depay_finalize(GObject * object)124 gst_rtp_qcelp_depay_finalize (GObject * object)
125 {
126 GstRtpQCELPDepay *depay;
127
128 depay = GST_RTP_QCELP_DEPAY (object);
129
130 if (depay->packets != NULL) {
131 g_ptr_array_foreach (depay->packets, (GFunc) gst_buffer_unref, NULL);
132 g_ptr_array_free (depay->packets, TRUE);
133 depay->packets = NULL;
134 }
135
136 G_OBJECT_CLASS (parent_class)->finalize (object);
137 }
138
139
140 static gboolean
gst_rtp_qcelp_depay_setcaps(GstRTPBaseDepayload * depayload,GstCaps * caps)141 gst_rtp_qcelp_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
142 {
143 GstCaps *srccaps;
144 gboolean res;
145
146 srccaps = gst_caps_new_simple ("audio/qcelp",
147 "channels", G_TYPE_INT, 1, "rate", G_TYPE_INT, 8000, NULL);
148 res = gst_pad_set_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (depayload), srccaps);
149 gst_caps_unref (srccaps);
150
151 return res;
152 }
153
154 static const gint frame_size[16] = {
155 1, 4, 8, 17, 35, -8, 0, 0,
156 0, 0, 0, 0, 0, 0, 1, 0
157 };
158
159 /* get the frame length, 0 is invalid, negative values are invalid but can be
160 * recovered from. */
161 static gint
get_frame_len(GstRtpQCELPDepay * depay,guint8 frame_type)162 get_frame_len (GstRtpQCELPDepay * depay, guint8 frame_type)
163 {
164 if (frame_type >= G_N_ELEMENTS (frame_size))
165 return 0;
166
167 return frame_size[frame_type];
168 }
169
170 static guint
count_packets(GstRtpQCELPDepay * depay,guint8 * data,guint size)171 count_packets (GstRtpQCELPDepay * depay, guint8 * data, guint size)
172 {
173 guint count = 0;
174
175 while (size > 0) {
176 gint frame_len;
177
178 frame_len = get_frame_len (depay, data[0]);
179
180 /* 0 is invalid and we throw away the remainder of the frames */
181 if (frame_len == 0)
182 break;
183
184 if (frame_len < 0)
185 frame_len = -frame_len;
186
187 if (frame_len > size)
188 break;
189
190 size -= frame_len;
191 data += frame_len;
192 count++;
193 }
194 return count;
195 }
196
197 static void
flush_packets(GstRtpQCELPDepay * depay)198 flush_packets (GstRtpQCELPDepay * depay)
199 {
200 guint i, size;
201
202 GST_DEBUG_OBJECT (depay, "flushing packets");
203
204 size = depay->packets->len;
205
206 for (i = 0; i < size; i++) {
207 GstBuffer *outbuf;
208
209 outbuf = g_ptr_array_index (depay->packets, i);
210 g_ptr_array_index (depay->packets, i) = NULL;
211
212 gst_rtp_base_depayload_push (GST_RTP_BASE_DEPAYLOAD (depay), outbuf);
213 }
214
215 /* and reset interleaving state */
216 depay->interleaved = FALSE;
217 depay->bundling = 0;
218 }
219
220 static void
add_packet(GstRtpQCELPDepay * depay,guint LLL,guint NNN,guint index,GstBuffer * outbuf)221 add_packet (GstRtpQCELPDepay * depay, guint LLL, guint NNN, guint index,
222 GstBuffer * outbuf)
223 {
224 guint idx;
225 GstBuffer *old;
226
227 /* figure out the position in the array, note that index is never 0 because we
228 * push those packets immediately. */
229 idx = NNN + ((LLL + 1) * (index - 1));
230
231 GST_DEBUG_OBJECT (depay, "adding packet at index %u", idx);
232 /* free old buffer (should not happen) */
233 old = g_ptr_array_index (depay->packets, idx);
234 if (old)
235 gst_buffer_unref (old);
236
237 /* store new buffer */
238 g_ptr_array_index (depay->packets, idx) = outbuf;
239 }
240
241 static GstBuffer *
create_erasure_buffer(GstRtpQCELPDepay * depay)242 create_erasure_buffer (GstRtpQCELPDepay * depay)
243 {
244 GstBuffer *outbuf;
245 GstMapInfo map;
246
247 outbuf = gst_buffer_new_and_alloc (1);
248 gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
249 map.data[0] = 14;
250 gst_buffer_unmap (outbuf, &map);
251
252 return outbuf;
253 }
254
255 static GstBuffer *
gst_rtp_qcelp_depay_process(GstRTPBaseDepayload * depayload,GstRTPBuffer * rtp)256 gst_rtp_qcelp_depay_process (GstRTPBaseDepayload * depayload,
257 GstRTPBuffer * rtp)
258 {
259 GstRtpQCELPDepay *depay;
260 GstBuffer *outbuf;
261 GstClockTime timestamp;
262 guint payload_len, offset, index;
263 guint8 *payload;
264 guint LLL, NNN;
265
266 depay = GST_RTP_QCELP_DEPAY (depayload);
267
268 payload_len = gst_rtp_buffer_get_payload_len (rtp);
269
270 if (payload_len < 2)
271 goto too_small;
272
273 timestamp = GST_BUFFER_PTS (rtp->buffer);
274
275 payload = gst_rtp_buffer_get_payload (rtp);
276
277 /* 0 1 2 3 4 5 6 7
278 * +-+-+-+-+-+-+-+-+
279 * |RR | LLL | NNN |
280 * +-+-+-+-+-+-+-+-+
281 */
282 /* RR = payload[0] >> 6; */
283 LLL = (payload[0] & 0x38) >> 3;
284 NNN = (payload[0] & 0x07);
285
286 payload_len--;
287 payload++;
288
289 GST_DEBUG_OBJECT (depay, "LLL %u, NNN %u", LLL, NNN);
290
291 if (LLL > 5)
292 goto invalid_lll;
293
294 if (NNN > LLL)
295 goto invalid_nnn;
296
297 if (LLL != 0) {
298 /* we are interleaved */
299 if (!depay->interleaved) {
300 guint size;
301
302 GST_DEBUG_OBJECT (depay, "starting interleaving group");
303 /* bundling is not allowed to change in one interleave group */
304 depay->bundling = count_packets (depay, payload, payload_len);
305 GST_DEBUG_OBJECT (depay, "got bundling of %u", depay->bundling);
306 /* we have one bundle where NNN goes from 0 to L, we don't store the index
307 * 0 frames, so L+1 packets. Each packet has 'bundling - 1' packets */
308 size = (depay->bundling - 1) * (LLL + 1);
309 /* create the array to hold the packets */
310 if (depay->packets == NULL)
311 depay->packets = g_ptr_array_sized_new (size);
312 GST_DEBUG_OBJECT (depay, "created packet array of size %u", size);
313 g_ptr_array_set_size (depay->packets, size);
314 /* we were previously not interleaved, figure out how much space we
315 * need to deinterleave */
316 depay->interleaved = TRUE;
317 }
318 } else {
319 /* we are not interleaved */
320 if (depay->interleaved) {
321 GST_DEBUG_OBJECT (depay, "stopping interleaving");
322 /* flush packets if we were previously interleaved */
323 flush_packets (depay);
324 }
325 depay->bundling = 0;
326 }
327
328 index = 0;
329 offset = 1;
330
331 while (payload_len > 0) {
332 gint frame_len;
333 gboolean do_erasure;
334
335 frame_len = get_frame_len (depay, payload[0]);
336 GST_DEBUG_OBJECT (depay, "got frame len %d", frame_len);
337
338 if (frame_len == 0)
339 goto invalid_frame;
340
341 if (frame_len < 0) {
342 /* need to add an erasure frame but we can recover */
343 frame_len = -frame_len;
344 do_erasure = TRUE;
345 } else {
346 do_erasure = FALSE;
347 }
348
349 if (frame_len > payload_len)
350 goto invalid_frame;
351
352 if (do_erasure) {
353 /* create erasure frame */
354 outbuf = create_erasure_buffer (depay);
355 } else {
356 /* each frame goes into its buffer */
357 outbuf = gst_rtp_buffer_get_payload_subbuffer (rtp, offset, frame_len);
358 }
359
360 GST_BUFFER_PTS (outbuf) = timestamp;
361 GST_BUFFER_DURATION (outbuf) = FRAME_DURATION;
362
363 gst_rtp_drop_non_audio_meta (depayload, outbuf);
364
365 if (!depay->interleaved || index == 0) {
366 /* not interleaved or first frame in packet, just push */
367 gst_rtp_base_depayload_push (depayload, outbuf);
368
369 if (timestamp != -1)
370 timestamp += FRAME_DURATION;
371 } else {
372 /* put in interleave buffer */
373 add_packet (depay, LLL, NNN, index, outbuf);
374
375 if (timestamp != -1)
376 timestamp += (FRAME_DURATION * (LLL + 1));
377 }
378
379 payload_len -= frame_len;
380 payload += frame_len;
381 offset += frame_len;
382 index++;
383
384 /* discard excess packets */
385 if (depay->bundling > 0 && depay->bundling <= index)
386 break;
387 }
388 while (index < depay->bundling) {
389 GST_DEBUG_OBJECT (depay, "filling with erasure buffer");
390 /* fill remainder with erasure packets */
391 outbuf = create_erasure_buffer (depay);
392 add_packet (depay, LLL, NNN, index, outbuf);
393 index++;
394 }
395 if (depay->interleaved && LLL == NNN) {
396 GST_DEBUG_OBJECT (depay, "interleave group ended, flushing");
397 /* we have the complete interleave group, flush */
398 flush_packets (depay);
399 }
400
401 return NULL;
402
403 /* ERRORS */
404 too_small:
405 {
406 GST_ELEMENT_WARNING (depay, STREAM, DECODE,
407 (NULL), ("QCELP RTP payload too small (%d)", payload_len));
408 return NULL;
409 }
410 invalid_lll:
411 {
412 GST_ELEMENT_WARNING (depay, STREAM, DECODE,
413 (NULL), ("QCELP RTP invalid LLL received (%d)", LLL));
414 return NULL;
415 }
416 invalid_nnn:
417 {
418 GST_ELEMENT_WARNING (depay, STREAM, DECODE,
419 (NULL), ("QCELP RTP invalid NNN received (%d)", NNN));
420 return NULL;
421 }
422 invalid_frame:
423 {
424 GST_ELEMENT_WARNING (depay, STREAM, DECODE,
425 (NULL), ("QCELP RTP invalid frame received"));
426 return NULL;
427 }
428 }
429