1 /* GStreamer
2 * Copyright (C) <2005> 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 #include <gst/rtp/gstrtpbuffer.h>
27
28 #include "gstrtpmp4gdepay.h"
29 #include "gstrtputils.h"
30
31 GST_DEBUG_CATEGORY_STATIC (rtpmp4gdepay_debug);
32 #define GST_CAT_DEFAULT (rtpmp4gdepay_debug)
33
34 static GstStaticPadTemplate gst_rtp_mp4g_depay_src_template =
35 GST_STATIC_PAD_TEMPLATE ("src",
36 GST_PAD_SRC,
37 GST_PAD_ALWAYS,
38 GST_STATIC_CAPS ("video/mpeg,"
39 "mpegversion=(int) 4,"
40 "systemstream=(boolean)false;"
41 "audio/mpeg," "mpegversion=(int) 4, " "stream-format=(string)raw")
42 );
43
44 static GstStaticPadTemplate gst_rtp_mp4g_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) { \"video\", \"audio\", \"application\" }, "
50 "clock-rate = (int) [1, MAX ], "
51 "encoding-name = (string) \"MPEG4-GENERIC\", "
52 /* required string params */
53 /* "streamtype = (string) { \"4\", \"5\" }, " Not set by Wowza 4 = video, 5 = audio */
54 /* "profile-level-id = (string) [1,MAX], " */
55 /* "config = (string) [1,MAX]" */
56 "mode = (string) { \"generic\", \"CELP-cbr\", \"CELP-vbr\", \"AAC-lbr\", \"AAC-hbr\" } "
57 /* Optional general parameters */
58 /* "objecttype = (string) [1,MAX], " */
59 /* "constantsize = (string) [1,MAX], " *//* constant size of each AU */
60 /* "constantduration = (string) [1,MAX], " *//* constant duration of each AU */
61 /* "maxdisplacement = (string) [1,MAX], " */
62 /* "de-interleavebuffersize = (string) [1,MAX], " */
63 /* Optional configuration parameters */
64 /* "sizelength = (string) [1, 32], " */
65 /* "indexlength = (string) [1, 32], " */
66 /* "indexdeltalength = (string) [1, 32], " */
67 /* "ctsdeltalength = (string) [1, 32], " */
68 /* "dtsdeltalength = (string) [1, 32], " */
69 /* "randomaccessindication = (string) {0, 1}, " */
70 /* "streamstateindication = (string) [0, 32], " */
71 /* "auxiliarydatasizelength = (string) [0, 32]" */ )
72 );
73
74 /* simple bitstream parser */
75 typedef struct
76 {
77 const guint8 *data;
78 const guint8 *end;
79 gint head; /* bitpos in the cache of next bit */
80 guint64 cache; /* cached bytes */
81 } GstBsParse;
82
83 static void
gst_bs_parse_init(GstBsParse * bs,const guint8 * data,guint size)84 gst_bs_parse_init (GstBsParse * bs, const guint8 * data, guint size)
85 {
86 bs->data = data;
87 bs->end = data + size;
88 bs->head = 0;
89 bs->cache = 0xffffffff;
90 }
91
92 static guint32
gst_bs_parse_read(GstBsParse * bs,guint n)93 gst_bs_parse_read (GstBsParse * bs, guint n)
94 {
95 guint32 res = 0;
96 gint shift;
97
98 if (n == 0)
99 return res;
100
101 /* fill up the cache if we need to */
102 while (bs->head < n) {
103 if (bs->data >= bs->end) {
104 /* we're at the end, can't produce more than head number of bits */
105 n = bs->head;
106 break;
107 }
108 /* shift bytes in cache, moving the head bits of the cache left */
109 bs->cache = (bs->cache << 8) | *bs->data++;
110 bs->head += 8;
111 }
112
113 /* bring the required bits down and truncate */
114 if ((shift = bs->head - n) > 0)
115 res = bs->cache >> shift;
116 else
117 res = bs->cache;
118
119 /* mask out required bits */
120 if (n < 32)
121 res &= (1 << n) - 1;
122
123 bs->head = shift;
124
125 return res;
126 }
127
128
129 #define gst_rtp_mp4g_depay_parent_class parent_class
130 G_DEFINE_TYPE (GstRtpMP4GDepay, gst_rtp_mp4g_depay,
131 GST_TYPE_RTP_BASE_DEPAYLOAD);
132
133 static void gst_rtp_mp4g_depay_finalize (GObject * object);
134
135 static gboolean gst_rtp_mp4g_depay_setcaps (GstRTPBaseDepayload * depayload,
136 GstCaps * caps);
137 static GstBuffer *gst_rtp_mp4g_depay_process (GstRTPBaseDepayload * depayload,
138 GstRTPBuffer * rtp);
139 static gboolean gst_rtp_mp4g_depay_handle_event (GstRTPBaseDepayload * filter,
140 GstEvent * event);
141
142 static GstStateChangeReturn gst_rtp_mp4g_depay_change_state (GstElement *
143 element, GstStateChange transition);
144
145
146 static void
gst_rtp_mp4g_depay_class_init(GstRtpMP4GDepayClass * klass)147 gst_rtp_mp4g_depay_class_init (GstRtpMP4GDepayClass * klass)
148 {
149 GObjectClass *gobject_class;
150 GstElementClass *gstelement_class;
151 GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
152
153 gobject_class = (GObjectClass *) klass;
154 gstelement_class = (GstElementClass *) klass;
155 gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
156
157 gobject_class->finalize = gst_rtp_mp4g_depay_finalize;
158
159 gstelement_class->change_state = gst_rtp_mp4g_depay_change_state;
160
161 gstrtpbasedepayload_class->process_rtp_packet = gst_rtp_mp4g_depay_process;
162 gstrtpbasedepayload_class->set_caps = gst_rtp_mp4g_depay_setcaps;
163 gstrtpbasedepayload_class->handle_event = gst_rtp_mp4g_depay_handle_event;
164
165 gst_element_class_add_static_pad_template (gstelement_class,
166 &gst_rtp_mp4g_depay_src_template);
167 gst_element_class_add_static_pad_template (gstelement_class,
168 &gst_rtp_mp4g_depay_sink_template);
169
170 gst_element_class_set_static_metadata (gstelement_class,
171 "RTP MPEG4 ES depayloader", "Codec/Depayloader/Network/RTP",
172 "Extracts MPEG4 elementary streams from RTP packets (RFC 3640)",
173 "Wim Taymans <wim.taymans@gmail.com>");
174
175 GST_DEBUG_CATEGORY_INIT (rtpmp4gdepay_debug, "rtpmp4gdepay", 0,
176 "MP4-generic RTP Depayloader");
177 }
178
179 static void
gst_rtp_mp4g_depay_init(GstRtpMP4GDepay * rtpmp4gdepay)180 gst_rtp_mp4g_depay_init (GstRtpMP4GDepay * rtpmp4gdepay)
181 {
182 rtpmp4gdepay->adapter = gst_adapter_new ();
183 rtpmp4gdepay->packets = g_queue_new ();
184 }
185
186 static void
gst_rtp_mp4g_depay_finalize(GObject * object)187 gst_rtp_mp4g_depay_finalize (GObject * object)
188 {
189 GstRtpMP4GDepay *rtpmp4gdepay;
190
191 rtpmp4gdepay = GST_RTP_MP4G_DEPAY (object);
192
193 g_object_unref (rtpmp4gdepay->adapter);
194 rtpmp4gdepay->adapter = NULL;
195 g_queue_free (rtpmp4gdepay->packets);
196 rtpmp4gdepay->packets = NULL;
197
198 G_OBJECT_CLASS (parent_class)->finalize (object);
199 }
200
201 static gint
gst_rtp_mp4g_depay_parse_int(GstStructure * structure,const gchar * field,gint def)202 gst_rtp_mp4g_depay_parse_int (GstStructure * structure, const gchar * field,
203 gint def)
204 {
205 const gchar *str;
206 gint res;
207
208 if ((str = gst_structure_get_string (structure, field)))
209 return atoi (str);
210
211 if (gst_structure_get_int (structure, field, &res))
212 return res;
213
214 return def;
215 }
216
217 static gboolean
gst_rtp_mp4g_depay_setcaps(GstRTPBaseDepayload * depayload,GstCaps * caps)218 gst_rtp_mp4g_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
219 {
220 GstStructure *structure;
221 GstRtpMP4GDepay *rtpmp4gdepay;
222 GstCaps *srccaps = NULL;
223 const gchar *str;
224 gint clock_rate;
225 gint someint;
226 gboolean res;
227
228 rtpmp4gdepay = GST_RTP_MP4G_DEPAY (depayload);
229
230 structure = gst_caps_get_structure (caps, 0);
231
232 if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
233 clock_rate = 90000; /* default */
234 depayload->clock_rate = clock_rate;
235
236 rtpmp4gdepay->check_adts = FALSE;
237
238 if ((str = gst_structure_get_string (structure, "media"))) {
239 if (strcmp (str, "audio") == 0) {
240 srccaps = gst_caps_new_simple ("audio/mpeg",
241 "mpegversion", G_TYPE_INT, 4, "stream-format", G_TYPE_STRING, "raw",
242 NULL);
243 rtpmp4gdepay->check_adts = TRUE;
244 } else if (strcmp (str, "video") == 0) {
245 srccaps = gst_caps_new_simple ("video/mpeg",
246 "mpegversion", G_TYPE_INT, 4,
247 "systemstream", G_TYPE_BOOLEAN, FALSE, NULL);
248 }
249 }
250 if (srccaps == NULL)
251 goto unknown_media;
252
253 /* these values are optional and have a default value of 0 (no header) */
254 rtpmp4gdepay->sizelength =
255 gst_rtp_mp4g_depay_parse_int (structure, "sizelength", 0);
256 rtpmp4gdepay->indexlength =
257 gst_rtp_mp4g_depay_parse_int (structure, "indexlength", 0);
258 rtpmp4gdepay->indexdeltalength =
259 gst_rtp_mp4g_depay_parse_int (structure, "indexdeltalength", 0);
260 rtpmp4gdepay->ctsdeltalength =
261 gst_rtp_mp4g_depay_parse_int (structure, "ctsdeltalength", 0);
262 rtpmp4gdepay->dtsdeltalength =
263 gst_rtp_mp4g_depay_parse_int (structure, "dtsdeltalength", 0);
264 someint =
265 gst_rtp_mp4g_depay_parse_int (structure, "randomaccessindication", 0);
266 rtpmp4gdepay->randomaccessindication = someint > 0 ? 1 : 0;
267 rtpmp4gdepay->streamstateindication =
268 gst_rtp_mp4g_depay_parse_int (structure, "streamstateindication", 0);
269 rtpmp4gdepay->auxiliarydatasizelength =
270 gst_rtp_mp4g_depay_parse_int (structure, "auxiliarydatasizelength", 0);
271 rtpmp4gdepay->constantSize =
272 gst_rtp_mp4g_depay_parse_int (structure, "constantsize", 0);
273 rtpmp4gdepay->constantDuration =
274 gst_rtp_mp4g_depay_parse_int (structure, "constantduration", 0);
275 rtpmp4gdepay->maxDisplacement =
276 gst_rtp_mp4g_depay_parse_int (structure, "maxdisplacement", 0);
277
278
279 /* get config string */
280 if ((str = gst_structure_get_string (structure, "config"))) {
281 GValue v = { 0 };
282
283 g_value_init (&v, GST_TYPE_BUFFER);
284 if (gst_value_deserialize (&v, str)) {
285 GstBuffer *buffer;
286
287 buffer = gst_value_get_buffer (&v);
288 gst_caps_set_simple (srccaps,
289 "codec_data", GST_TYPE_BUFFER, buffer, NULL);
290 g_value_unset (&v);
291 } else {
292 g_warning ("cannot convert config to buffer");
293 }
294 }
295
296 res = gst_pad_set_caps (depayload->srcpad, srccaps);
297 gst_caps_unref (srccaps);
298
299 return res;
300
301 /* ERRORS */
302 unknown_media:
303 {
304 GST_DEBUG_OBJECT (rtpmp4gdepay, "Unknown media type");
305 return FALSE;
306 }
307 }
308
309 static void
gst_rtp_mp4g_depay_clear_queue(GstRtpMP4GDepay * rtpmp4gdepay)310 gst_rtp_mp4g_depay_clear_queue (GstRtpMP4GDepay * rtpmp4gdepay)
311 {
312 GstBuffer *outbuf;
313
314 while ((outbuf = g_queue_pop_head (rtpmp4gdepay->packets)))
315 gst_buffer_unref (outbuf);
316 }
317
318 static void
gst_rtp_mp4g_depay_reset(GstRtpMP4GDepay * rtpmp4gdepay)319 gst_rtp_mp4g_depay_reset (GstRtpMP4GDepay * rtpmp4gdepay)
320 {
321 gst_adapter_clear (rtpmp4gdepay->adapter);
322 rtpmp4gdepay->max_AU_index = -1;
323 rtpmp4gdepay->next_AU_index = -1;
324 rtpmp4gdepay->prev_AU_index = -1;
325 rtpmp4gdepay->prev_rtptime = -1;
326 rtpmp4gdepay->last_AU_index = -1;
327 gst_rtp_mp4g_depay_clear_queue (rtpmp4gdepay);
328 }
329
330 static void
gst_rtp_mp4g_depay_push_outbuf(GstRtpMP4GDepay * rtpmp4gdepay,GstBuffer * outbuf,guint AU_index)331 gst_rtp_mp4g_depay_push_outbuf (GstRtpMP4GDepay * rtpmp4gdepay,
332 GstBuffer * outbuf, guint AU_index)
333 {
334 gboolean discont = FALSE;
335
336 if (AU_index != rtpmp4gdepay->next_AU_index) {
337 GST_DEBUG_OBJECT (rtpmp4gdepay, "discont, expected AU_index %u",
338 rtpmp4gdepay->next_AU_index);
339 GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DISCONT);
340 discont = TRUE;
341 }
342
343 GST_DEBUG_OBJECT (rtpmp4gdepay, "pushing %sAU_index %u",
344 discont ? "" : "expected ", AU_index);
345
346 gst_rtp_drop_meta (GST_ELEMENT_CAST (rtpmp4gdepay), outbuf, 0);
347 gst_rtp_base_depayload_push (GST_RTP_BASE_DEPAYLOAD (rtpmp4gdepay), outbuf);
348 rtpmp4gdepay->next_AU_index = AU_index + 1;
349 }
350
351 static void
gst_rtp_mp4g_depay_flush_queue(GstRtpMP4GDepay * rtpmp4gdepay)352 gst_rtp_mp4g_depay_flush_queue (GstRtpMP4GDepay * rtpmp4gdepay)
353 {
354 GstBuffer *outbuf;
355 guint AU_index;
356
357 while ((outbuf = g_queue_pop_head (rtpmp4gdepay->packets))) {
358 AU_index = GST_BUFFER_OFFSET (outbuf);
359
360 GST_DEBUG_OBJECT (rtpmp4gdepay, "next available AU_index %u", AU_index);
361
362 gst_rtp_mp4g_depay_push_outbuf (rtpmp4gdepay, outbuf, AU_index);
363 }
364 }
365
366 static void
gst_rtp_mp4g_depay_queue(GstRtpMP4GDepay * rtpmp4gdepay,GstBuffer * outbuf)367 gst_rtp_mp4g_depay_queue (GstRtpMP4GDepay * rtpmp4gdepay, GstBuffer * outbuf)
368 {
369 guint AU_index = GST_BUFFER_OFFSET (outbuf);
370
371 if (rtpmp4gdepay->next_AU_index == -1) {
372 GST_DEBUG_OBJECT (rtpmp4gdepay, "Init AU counter %u", AU_index);
373 rtpmp4gdepay->next_AU_index = AU_index;
374 }
375
376 if (rtpmp4gdepay->next_AU_index == AU_index) {
377 GST_DEBUG_OBJECT (rtpmp4gdepay, "pushing expected AU_index %u", AU_index);
378
379 /* we received the expected packet, push it and flush as much as we can from
380 * the queue */
381 gst_rtp_mp4g_depay_push_outbuf (rtpmp4gdepay, outbuf, AU_index);
382
383 while ((outbuf = g_queue_peek_head (rtpmp4gdepay->packets))) {
384 AU_index = GST_BUFFER_OFFSET (outbuf);
385
386 GST_DEBUG_OBJECT (rtpmp4gdepay, "next available AU_index %u", AU_index);
387
388 if (rtpmp4gdepay->next_AU_index == AU_index) {
389 outbuf = g_queue_pop_head (rtpmp4gdepay->packets);
390 gst_rtp_mp4g_depay_push_outbuf (rtpmp4gdepay, outbuf, AU_index);
391 } else {
392 GST_DEBUG_OBJECT (rtpmp4gdepay, "waiting for next AU_index %u",
393 rtpmp4gdepay->next_AU_index);
394 break;
395 }
396 }
397 } else {
398 GList *list;
399
400 GST_DEBUG_OBJECT (rtpmp4gdepay, "queueing AU_index %u", AU_index);
401
402 /* loop the list to skip strictly smaller AU_index buffers */
403 for (list = rtpmp4gdepay->packets->head; list; list = g_list_next (list)) {
404 guint idx;
405 gint gap;
406
407 idx = GST_BUFFER_OFFSET (GST_BUFFER_CAST (list->data));
408
409 /* compare the new seqnum to the one in the buffer */
410 gap = (gint) (idx - AU_index);
411
412 GST_DEBUG_OBJECT (rtpmp4gdepay, "compare with AU_index %u, gap %d", idx,
413 gap);
414
415 /* AU_index <= idx, we can stop looking */
416 if (G_LIKELY (gap > 0))
417 break;
418 }
419 if (G_LIKELY (list))
420 g_queue_insert_before (rtpmp4gdepay->packets, list, outbuf);
421 else
422 g_queue_push_tail (rtpmp4gdepay->packets, outbuf);
423 }
424 }
425
426 static GstBuffer *
gst_rtp_mp4g_depay_process(GstRTPBaseDepayload * depayload,GstRTPBuffer * rtp)427 gst_rtp_mp4g_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)
428 {
429 GstRtpMP4GDepay *rtpmp4gdepay;
430 GstBuffer *outbuf = NULL;
431 GstClockTime timestamp;
432
433 rtpmp4gdepay = GST_RTP_MP4G_DEPAY (depayload);
434
435 /* flush remaining data on discont */
436 if (GST_BUFFER_IS_DISCONT (rtp->buffer)) {
437 GST_DEBUG_OBJECT (rtpmp4gdepay, "received DISCONT");
438 gst_adapter_clear (rtpmp4gdepay->adapter);
439 }
440
441 timestamp = GST_BUFFER_PTS (rtp->buffer);
442
443 {
444 gint payload_len, payload_AU;
445 guint8 *payload;
446 guint32 rtptime;
447 guint AU_headers_len;
448 guint AU_size, AU_index, AU_index_delta, payload_AU_size;
449 gboolean M;
450
451 payload_len = gst_rtp_buffer_get_payload_len (rtp);
452 payload = gst_rtp_buffer_get_payload (rtp);
453
454 GST_DEBUG_OBJECT (rtpmp4gdepay, "received payload of %d", payload_len);
455
456 rtptime = gst_rtp_buffer_get_timestamp (rtp);
457 M = gst_rtp_buffer_get_marker (rtp);
458
459 if (rtpmp4gdepay->sizelength > 0) {
460 gint num_AU_headers, AU_headers_bytes, i;
461 GstBsParse bs;
462
463 if (payload_len < 2)
464 goto short_payload;
465
466 /* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- .. -+-+-+-+-+-+-+-+-+-+
467 * |AU-headers-length|AU-header|AU-header| |AU-header|padding|
468 * | | (1) | (2) | | (n) * | bits |
469 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- .. -+-+-+-+-+-+-+-+-+-+
470 *
471 * The length is 2 bytes and contains the length of the following
472 * AU-headers in bits.
473 */
474 AU_headers_len = (payload[0] << 8) | payload[1];
475 AU_headers_bytes = (AU_headers_len + 7) / 8;
476 num_AU_headers = AU_headers_len / 16;
477
478 GST_DEBUG_OBJECT (rtpmp4gdepay, "AU headers len %d, bytes %d, num %d",
479 AU_headers_len, AU_headers_bytes, num_AU_headers);
480
481 /* skip header */
482 payload += 2;
483 payload_len -= 2;
484
485 if (payload_len < AU_headers_bytes)
486 goto short_payload;
487
488 /* skip special headers, point to first payload AU */
489 payload_AU = 2 + AU_headers_bytes;
490 payload_AU_size = payload_len - AU_headers_bytes;
491
492 if (G_UNLIKELY (rtpmp4gdepay->auxiliarydatasizelength)) {
493 gint aux_size;
494
495 /* point the bitstream parser to the first auxiliary data bit */
496 gst_bs_parse_init (&bs, payload + AU_headers_bytes,
497 payload_len - AU_headers_bytes);
498 aux_size =
499 gst_bs_parse_read (&bs, rtpmp4gdepay->auxiliarydatasizelength);
500 /* convert to bytes */
501 aux_size = (aux_size + 7) / 8;
502 /* AU data then follows auxiliary data */
503 if (payload_AU_size < aux_size)
504 goto short_payload;
505 payload_AU += aux_size;
506 payload_AU_size -= aux_size;
507 }
508
509 /* point the bitstream parser to the first AU header bit */
510 gst_bs_parse_init (&bs, payload, payload_len);
511 AU_index = AU_index_delta = 0;
512
513 for (i = 0; i < num_AU_headers && payload_AU_size > 0; i++) {
514 /* parse AU header
515 * +---------------------------------------+
516 * | AU-size |
517 * +---------------------------------------+
518 * | AU-Index / AU-Index-delta |
519 * +---------------------------------------+
520 * | CTS-flag |
521 * +---------------------------------------+
522 * | CTS-delta |
523 * +---------------------------------------+
524 * | DTS-flag |
525 * +---------------------------------------+
526 * | DTS-delta |
527 * +---------------------------------------+
528 * | RAP-flag |
529 * +---------------------------------------+
530 * | Stream-state |
531 * +---------------------------------------+
532 */
533 AU_size = gst_bs_parse_read (&bs, rtpmp4gdepay->sizelength);
534
535 /* calculate the AU_index, which is only on the first AU of the packet
536 * and the AU_index_delta on the other AUs. This will be used to
537 * reconstruct the AU ordering when interleaving. */
538 if (i == 0) {
539 AU_index = gst_bs_parse_read (&bs, rtpmp4gdepay->indexlength);
540
541 GST_DEBUG_OBJECT (rtpmp4gdepay, "AU index %u", AU_index);
542
543 if (AU_index == 0 && rtpmp4gdepay->prev_AU_index == 0) {
544 gint diff;
545 gint cd;
546
547 /* if we see two consecutive packets with AU_index of 0, we can
548 * assume we have constantDuration packets. Since we don't have
549 * the index we must use the AU duration to calculate the
550 * index. Get the diff between the timestamps first, this can be
551 * positive or negative. */
552 if (rtpmp4gdepay->prev_rtptime <= rtptime)
553 diff = rtptime - rtpmp4gdepay->prev_rtptime;
554 else
555 diff = -(rtpmp4gdepay->prev_rtptime - rtptime);
556
557 /* if no constantDuration was given, make one */
558 if (rtpmp4gdepay->constantDuration != 0) {
559 cd = rtpmp4gdepay->constantDuration;
560 GST_DEBUG_OBJECT (depayload, "using constantDuration %d", cd);
561 } else if (rtpmp4gdepay->prev_AU_num > 0) {
562 /* use number of packets and of previous frame */
563 cd = diff / rtpmp4gdepay->prev_AU_num;
564 GST_DEBUG_OBJECT (depayload, "guessing constantDuration %d", cd);
565 if (!GST_BUFFER_IS_DISCONT (rtp->buffer)) {
566 /* rfc3640 - 3.2.3.2
567 * if we see two consecutive packets with AU_index of 0 and
568 * there has been no discontinuity, we must conclude that this
569 * value of constantDuration is correct from now on. */
570 GST_DEBUG_OBJECT (depayload,
571 "constantDuration of %d detected", cd);
572 rtpmp4gdepay->constantDuration = cd;
573 }
574 } else {
575 /* assume this frame has the same number of packets as the
576 * previous one */
577 cd = diff / num_AU_headers;
578 GST_DEBUG_OBJECT (depayload, "guessing constantDuration %d", cd);
579 }
580
581 if (cd > 0) {
582 /* get the number of packets by dividing with the duration */
583 diff /= cd;
584 } else {
585 diff = 0;
586 }
587
588 rtpmp4gdepay->last_AU_index += diff;
589 rtpmp4gdepay->prev_AU_index = AU_index;
590
591 AU_index = rtpmp4gdepay->last_AU_index;
592
593 GST_DEBUG_OBJECT (rtpmp4gdepay, "diff %d, AU index %u", diff,
594 AU_index);
595 } else {
596 rtpmp4gdepay->prev_AU_index = AU_index;
597 rtpmp4gdepay->last_AU_index = AU_index;
598 }
599
600 /* keep track of the higest AU_index */
601 if (rtpmp4gdepay->max_AU_index != -1
602 && rtpmp4gdepay->max_AU_index <= AU_index) {
603 GST_DEBUG_OBJECT (rtpmp4gdepay, "new interleave group, flushing");
604 /* a new interleave group started, flush */
605 gst_rtp_mp4g_depay_flush_queue (rtpmp4gdepay);
606 }
607 if (G_UNLIKELY (!rtpmp4gdepay->maxDisplacement &&
608 rtpmp4gdepay->max_AU_index != -1
609 && rtpmp4gdepay->max_AU_index >= AU_index)) {
610 GstBuffer *outbuf;
611
612 /* some broken non-interleaved streams have AU-index jumping around
613 * all over the place, apparently assuming receiver disregards */
614 GST_DEBUG_OBJECT (rtpmp4gdepay, "non-interleaved broken AU indices;"
615 " forcing continuous flush");
616 /* reset AU to avoid repeated DISCONT in such case */
617 outbuf = g_queue_peek_head (rtpmp4gdepay->packets);
618 if (G_LIKELY (outbuf)) {
619 rtpmp4gdepay->next_AU_index = GST_BUFFER_OFFSET (outbuf);
620 gst_rtp_mp4g_depay_flush_queue (rtpmp4gdepay);
621 }
622 /* rebase next_AU_index to current rtp's first AU_index */
623 rtpmp4gdepay->next_AU_index = AU_index;
624 }
625 rtpmp4gdepay->prev_rtptime = rtptime;
626 rtpmp4gdepay->prev_AU_num = num_AU_headers;
627 } else {
628 AU_index_delta =
629 gst_bs_parse_read (&bs, rtpmp4gdepay->indexdeltalength);
630 AU_index += AU_index_delta + 1;
631 }
632 /* keep track of highest AU_index */
633 if (rtpmp4gdepay->max_AU_index == -1
634 || AU_index > rtpmp4gdepay->max_AU_index)
635 rtpmp4gdepay->max_AU_index = AU_index;
636
637 /* the presentation time offset, a 2s-complement value, we need this to
638 * calculate the timestamp on the output packet. */
639 if (rtpmp4gdepay->ctsdeltalength > 0) {
640 if (gst_bs_parse_read (&bs, 1))
641 gst_bs_parse_read (&bs, rtpmp4gdepay->ctsdeltalength);
642 }
643 /* the decoding time offset, a 2s-complement value */
644 if (rtpmp4gdepay->dtsdeltalength > 0) {
645 if (gst_bs_parse_read (&bs, 1))
646 gst_bs_parse_read (&bs, rtpmp4gdepay->dtsdeltalength);
647 }
648 /* RAP-flag to indicate that the AU contains a keyframe */
649 if (rtpmp4gdepay->randomaccessindication)
650 gst_bs_parse_read (&bs, 1);
651 /* stream-state */
652 if (rtpmp4gdepay->streamstateindication > 0)
653 gst_bs_parse_read (&bs, rtpmp4gdepay->streamstateindication);
654
655 GST_DEBUG_OBJECT (rtpmp4gdepay, "size %d, index %d, delta %d", AU_size,
656 AU_index, AU_index_delta);
657
658 /* fragmented pakets have the AU_size set to the size of the
659 * unfragmented AU. */
660 if (AU_size > payload_AU_size)
661 AU_size = payload_AU_size;
662
663 /* collect stuff in the adapter, strip header from payload and push in
664 * the adapter */
665 outbuf =
666 gst_rtp_buffer_get_payload_subbuffer (rtp, payload_AU, AU_size);
667 gst_adapter_push (rtpmp4gdepay->adapter, outbuf);
668
669 if (M) {
670 guint32 v = 0;
671 guint avail;
672
673 /* packet is complete, flush */
674 avail = gst_adapter_available (rtpmp4gdepay->adapter);
675
676 /* Some broken senders send ADTS headers (e.g. some Sony cameras).
677 * Try to detect those and skip them (still needs config set), but
678 * don't check every frame, only the first (unless we detect ADTS) */
679 if (rtpmp4gdepay->check_adts && avail >= 7) {
680 if (gst_adapter_masked_scan_uint32_peek (rtpmp4gdepay->adapter,
681 0xfffe0000, 0xfff00000, 0, 4, &v) == 0) {
682 guint adts_hdr_len = (((v >> 16) & 0x1) == 0) ? 9 : 7;
683 if (avail > adts_hdr_len) {
684 GST_WARNING_OBJECT (rtpmp4gdepay, "Detected ADTS header of "
685 "%u bytes, skipping", adts_hdr_len);
686 gst_adapter_flush (rtpmp4gdepay->adapter, adts_hdr_len);
687 avail -= adts_hdr_len;
688 }
689 } else {
690 rtpmp4gdepay->check_adts = FALSE;
691 }
692 }
693
694 outbuf = gst_adapter_take_buffer (rtpmp4gdepay->adapter, avail);
695
696 /* copy some of the fields we calculated above on the buffer. We also
697 * copy the AU_index so that we can sort the packets in our queue. */
698 GST_BUFFER_PTS (outbuf) = timestamp;
699 GST_BUFFER_OFFSET (outbuf) = AU_index;
700
701 if (rtpmp4gdepay->constantDuration != 0) {
702 /* if we have constantDuration, calculate timestamp for next AU
703 * in this RTP packet. */
704 timestamp += (rtpmp4gdepay->constantDuration * GST_SECOND) /
705 depayload->clock_rate;
706 } else {
707 /* otherwise, make sure we don't use the timestamp again for other
708 * AUs. */
709 timestamp = GST_CLOCK_TIME_NONE;
710 }
711
712 GST_DEBUG_OBJECT (depayload,
713 "pushing buffer of size %" G_GSIZE_FORMAT,
714 gst_buffer_get_size (outbuf));
715
716 gst_rtp_mp4g_depay_queue (rtpmp4gdepay, outbuf);
717
718 }
719 payload_AU += AU_size;
720 payload_AU_size -= AU_size;
721 }
722 } else {
723 /* push complete buffer in adapter */
724 outbuf = gst_rtp_buffer_get_payload_subbuffer (rtp, 0, payload_len);
725 gst_adapter_push (rtpmp4gdepay->adapter, outbuf);
726
727 /* if this was the last packet of the VOP, create and push a buffer */
728 if (M) {
729 guint avail;
730
731 avail = gst_adapter_available (rtpmp4gdepay->adapter);
732
733 outbuf = gst_adapter_take_buffer (rtpmp4gdepay->adapter, avail);
734
735 GST_DEBUG ("gst_rtp_mp4g_depay_chain: pushing buffer of size %"
736 G_GSIZE_FORMAT, gst_buffer_get_size (outbuf));
737
738 return outbuf;
739 }
740 }
741 }
742
743 return NULL;
744
745 /* ERRORS */
746 short_payload:
747 {
748 GST_ELEMENT_WARNING (rtpmp4gdepay, STREAM, DECODE,
749 ("Packet payload was too short."), (NULL));
750 return NULL;
751 }
752 }
753
754 static gboolean
gst_rtp_mp4g_depay_handle_event(GstRTPBaseDepayload * filter,GstEvent * event)755 gst_rtp_mp4g_depay_handle_event (GstRTPBaseDepayload * filter, GstEvent * event)
756 {
757 gboolean ret;
758 GstRtpMP4GDepay *rtpmp4gdepay;
759
760 rtpmp4gdepay = GST_RTP_MP4G_DEPAY (filter);
761
762 switch (GST_EVENT_TYPE (event)) {
763 case GST_EVENT_FLUSH_STOP:
764 gst_rtp_mp4g_depay_reset (rtpmp4gdepay);
765 break;
766 default:
767 break;
768 }
769
770 ret =
771 GST_RTP_BASE_DEPAYLOAD_CLASS (parent_class)->handle_event (filter, event);
772
773 return ret;
774 }
775
776 static GstStateChangeReturn
gst_rtp_mp4g_depay_change_state(GstElement * element,GstStateChange transition)777 gst_rtp_mp4g_depay_change_state (GstElement * element,
778 GstStateChange transition)
779 {
780 GstRtpMP4GDepay *rtpmp4gdepay;
781 GstStateChangeReturn ret;
782
783 rtpmp4gdepay = GST_RTP_MP4G_DEPAY (element);
784
785 switch (transition) {
786 case GST_STATE_CHANGE_READY_TO_PAUSED:
787 gst_rtp_mp4g_depay_reset (rtpmp4gdepay);
788 break;
789 default:
790 break;
791 }
792
793 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
794
795 switch (transition) {
796 case GST_STATE_CHANGE_PAUSED_TO_READY:
797 gst_rtp_mp4g_depay_reset (rtpmp4gdepay);
798 break;
799 default:
800 break;
801 }
802 return ret;
803 }
804
805 gboolean
gst_rtp_mp4g_depay_plugin_init(GstPlugin * plugin)806 gst_rtp_mp4g_depay_plugin_init (GstPlugin * plugin)
807 {
808 return gst_element_register (plugin, "rtpmp4gdepay",
809 GST_RANK_SECONDARY, GST_TYPE_RTP_MP4G_DEPAY);
810 }
811