2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2001 Thomas <thomas@apestaart.org>
4 * 2005,2006 Wim Taymans <wim@fluendo.com>
6 * adder.c: Adder element, N in, one out, samples are added
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
24 * SECTION:element-adder
26 * The adder allows to mix several streams into one by adding the data.
27 * Mixed data is clamped to the min/max values of the data format.
29 * The adder currently mixes all data received on the sinkpads as soon as
30 * possible without trying to synchronize the streams.
33 * <title>Example launch line</title>
35 * gst-launch audiotestsrc freq=100 ! adder name=mix ! audioconvert ! alsasink audiotestsrc freq=500 ! mix.
36 * ]| This pipeline produces two sine waves mixed together.
39 * Last reviewed on 2006-05-09 (0.10.7)
41 /* Element-Checklist-Version: 5 */
47 #include <gst/audio/audio.h>
48 #include <string.h> /* strcmp */
49 /*#include <liboil/liboil.h>*/
51 /* highest positive/lowest negative x-bit value we can use for clamping */
52 #define MAX_INT_32 ((gint32) (0x7fffffff))
53 #define MAX_INT_16 ((gint16) (0x7fff))
54 #define MAX_INT_8 ((gint8) (0x7f))
55 #define MAX_UINT_32 ((guint32)(0xffffffff))
56 #define MAX_UINT_16 ((guint16)(0xffff))
57 #define MAX_UINT_8 ((guint8) (0xff))
59 #define MIN_INT_32 ((gint32) (0x80000000))
60 #define MIN_INT_16 ((gint16) (0x8000))
61 #define MIN_INT_8 ((gint8) (0x80))
62 #define MIN_UINT_32 ((guint32)(0x00000000))
63 #define MIN_UINT_16 ((guint16)(0x0000))
64 #define MIN_UINT_8 ((guint8) (0x00))
66 #define GST_CAT_DEFAULT gst_adder_debug
67 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
69 /* elementfactory information */
73 "rate = (int) [ 1, MAX ], " \
74 "channels = (int) [ 1, MAX ], " \
75 "endianness = (int) BYTE_ORDER, " \
76 "width = (int) 32, " \
77 "depth = (int) 32, " \
78 "signed = (boolean) { true, false } ;" \
80 "rate = (int) [ 1, MAX ], " \
81 "channels = (int) [ 1, MAX ], " \
82 "endianness = (int) BYTE_ORDER, " \
83 "width = (int) 16, " \
84 "depth = (int) 16, " \
85 "signed = (boolean) { true, false } ;" \
87 "rate = (int) [ 1, MAX ], " \
88 "channels = (int) [ 1, MAX ], " \
89 "endianness = (int) BYTE_ORDER, " \
92 "signed = (boolean) { true, false } ;" \
93 "audio/x-raw-float, " \
94 "rate = (int) [ 1, MAX ], " \
95 "channels = (int) [ 1, MAX ], " \
96 "endianness = (int) BYTE_ORDER, " \
97 "width = (int) { 32, 64 }"
99 static GstStaticPadTemplate gst_adder_src_template =
100 GST_STATIC_PAD_TEMPLATE ("src",
103 GST_STATIC_CAPS (CAPS)
106 static GstStaticPadTemplate gst_adder_sink_template =
107 GST_STATIC_PAD_TEMPLATE ("sink%d",
110 GST_STATIC_CAPS (CAPS)
113 static void gst_adder_class_init (GstAdderClass * klass);
114 static void gst_adder_init (GstAdder * adder);
115 static void gst_adder_finalize (GObject * object);
117 static gboolean gst_adder_setcaps (GstPad * pad, GstCaps * caps);
118 static gboolean gst_adder_query (GstPad * pad, GstQuery * query);
119 static gboolean gst_adder_src_event (GstPad * pad, GstEvent * event);
120 static gboolean gst_adder_sink_event (GstPad * pad, GstEvent * event);
122 static GstPad *gst_adder_request_new_pad (GstElement * element,
123 GstPadTemplate * temp, const gchar * unused);
124 static void gst_adder_release_pad (GstElement * element, GstPad * pad);
126 static GstStateChangeReturn gst_adder_change_state (GstElement * element,
127 GstStateChange transition);
129 static GstFlowReturn gst_adder_collected (GstCollectPads * pads,
132 static GstElementClass *parent_class = NULL;
135 gst_adder_get_type (void)
137 static GType adder_type = 0;
139 if (G_UNLIKELY (adder_type == 0)) {
140 static const GTypeInfo adder_info = {
141 sizeof (GstAdderClass), NULL, NULL,
142 (GClassInitFunc) gst_adder_class_init, NULL, NULL,
143 sizeof (GstAdder), 0,
144 (GInstanceInitFunc) gst_adder_init,
147 adder_type = g_type_register_static (GST_TYPE_ELEMENT, "GstAdder",
149 GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "adder", 0,
150 "audio channel mixing element");
155 /* clipping versions (for int)
156 * FIXME: what about: oil_add_s16 (out, out, in, bytes / sizeof (type))
158 #define MAKE_FUNC(name,type,ttype,min,max) \
159 static void name (type *out, type *in, gint bytes) { \
162 for (i = 0; i < bytes / sizeof (type); i++) { \
163 add = (ttype)out[i] + (ttype)in[i]; \
164 out[i] = CLAMP (add, min, max); \
168 /* unsigned versions (for int) */
169 #define MAKE_FUNC_US(name,type,ttype,max) \
170 static void name (type *out, type *in, gint bytes) { \
173 for (i = 0; i < bytes / sizeof (type); i++) { \
174 add = (ttype)out[i] + (ttype)in[i]; \
175 out[i] = ((add <= max) ? add : max); \
179 /* non-clipping versions (for float) */
180 #define MAKE_FUNC_NC(name,type) \
181 static void name (type *out, type *in, gint bytes) { \
183 for (i = 0; i < bytes / sizeof (type); i++) \
188 /* right now, the liboil function don't seems to be faster on x86
189 * time gst-launch audiotestsrc num-buffers=50000 ! audio/x-raw-float ! adder name=m ! fakesink audiotestsrc num-buffers=50000 ! audio/x-raw-float ! m.
190 * time gst-launch audiotestsrc num-buffers=50000 ! audio/x-raw-float,width=32 ! adder name=m ! fakesink audiotestsrc num-buffers=50000 ! audio/x-raw-float,width=32 ! m.
193 add_float32 (gfloat * out, gfloat * in, gint bytes)
195 oil_add_f32 (out, out, in, bytes / sizeof (gfloat));
199 add_float64 (gdouble * out, gdouble * in, gint bytes)
201 oil_add_f64 (out, out, in, bytes / sizeof (gdouble));
206 MAKE_FUNC (add_int32, gint32, gint64, MIN_INT_32, MAX_INT_32)
207 MAKE_FUNC (add_int16, gint16, gint32, MIN_INT_16, MAX_INT_16)
208 MAKE_FUNC (add_int8, gint8, gint16, MIN_INT_8, MAX_INT_8)
209 MAKE_FUNC_US (add_uint32, guint32, guint64, MAX_UINT_32)
210 MAKE_FUNC_US (add_uint16, guint16, guint32, MAX_UINT_16)
211 MAKE_FUNC_US (add_uint8, guint8, guint16, MAX_UINT_8)
212 MAKE_FUNC_NC (add_float64, gdouble)
213 MAKE_FUNC_NC (add_float32, gfloat)
216 /* we can only accept caps that we and downstream can handle. */
218 gst_adder_sink_getcaps (GstPad * pad)
221 GstCaps *result, *peercaps, *sinkcaps;
223 adder = GST_ADDER (GST_PAD_PARENT (pad));
225 GST_OBJECT_LOCK (adder);
226 /* get the downstream possible caps */
227 peercaps = gst_pad_peer_get_caps (adder->srcpad);
228 /* get the allowed caps on this sinkpad, we use the fixed caps function so
229 * that it does not call recursively in this function. */
230 sinkcaps = gst_pad_get_fixed_caps_func (pad);
232 /* if the peer has caps, intersect */
233 GST_DEBUG_OBJECT (adder, "intersecting peer and template caps");
234 result = gst_caps_intersect (peercaps, sinkcaps);
235 gst_caps_unref (peercaps);
236 gst_caps_unref (sinkcaps);
238 /* the peer has no caps (or there is no peer), just use the allowed caps
239 * of this sinkpad. */
240 GST_DEBUG_OBJECT (adder, "no peer caps, using sinkcaps");
243 GST_OBJECT_UNLOCK (adder);
248 /* the first caps we receive on any of the sinkpads will define the caps for all
249 * the other sinkpads because we can only mix streams with the same caps.
252 gst_adder_setcaps (GstPad * pad, GstCaps * caps)
256 GstStructure *structure;
257 const char *media_type;
259 adder = GST_ADDER (GST_PAD_PARENT (pad));
261 GST_LOG_OBJECT (adder, "setting caps on pad %p,%s to %" GST_PTR_FORMAT, pad,
262 GST_PAD_NAME (pad), caps);
264 /* FIXME, see if the other pads can accept the format. Also lock the
265 * format on the other pads to this new format. */
266 GST_OBJECT_LOCK (adder);
267 pads = GST_ELEMENT (adder)->pads;
269 GstPad *otherpad = GST_PAD (pads->data);
271 if (otherpad != pad) {
272 gst_caps_replace (&GST_PAD_CAPS (otherpad), caps);
274 pads = g_list_next (pads);
276 GST_OBJECT_UNLOCK (adder);
279 structure = gst_caps_get_structure (caps, 0);
280 media_type = gst_structure_get_name (structure);
281 if (strcmp (media_type, "audio/x-raw-int") == 0) {
282 adder->format = GST_ADDER_FORMAT_INT;
283 gst_structure_get_int (structure, "width", &adder->width);
284 gst_structure_get_int (structure, "depth", &adder->depth);
285 gst_structure_get_int (structure, "endianness", &adder->endianness);
286 gst_structure_get_boolean (structure, "signed", &adder->is_signed);
288 GST_INFO_OBJECT (adder, "parse_caps sets adder to format int, %d bit",
291 if (adder->endianness != G_BYTE_ORDER)
294 switch (adder->width) {
296 adder->func = (adder->is_signed ?
297 (GstAdderFunction) add_int8 : (GstAdderFunction) add_uint8);
300 adder->func = (adder->is_signed ?
301 (GstAdderFunction) add_int16 : (GstAdderFunction) add_uint16);
304 adder->func = (adder->is_signed ?
305 (GstAdderFunction) add_int32 : (GstAdderFunction) add_uint32);
310 } else if (strcmp (media_type, "audio/x-raw-float") == 0) {
311 adder->format = GST_ADDER_FORMAT_FLOAT;
312 gst_structure_get_int (structure, "width", &adder->width);
313 gst_structure_get_int (structure, "endianness", &adder->endianness);
315 GST_INFO_OBJECT (adder, "parse_caps sets adder to format float, %d bit",
318 if (adder->endianness != G_BYTE_ORDER)
321 switch (adder->width) {
323 adder->func = (GstAdderFunction) add_float32;
326 adder->func = (GstAdderFunction) add_float64;
335 gst_structure_get_int (structure, "channels", &adder->channels);
336 gst_structure_get_int (structure, "rate", &adder->rate);
338 adder->bps = (adder->width / 8) * adder->channels;
345 GST_DEBUG_OBJECT (adder, "unsupported format set as caps");
350 /* FIXME, the duration query should reflect how long you will produce
351 * data, that is the amount of stream time until you will emit EOS.
353 * For synchronized mixing this is always the max of all the durations
354 * of upstream since we emit EOS when all of them finished.
356 * We don't do synchronized mixing so this really depends on where the
357 * streams where punched in and what their relative offsets are against
358 * eachother which we can get from the first timestamps we see.
360 * When we add a new stream (or remove a stream) the duration might
361 * also become invalid again and we need to post a new DURATION
362 * message to notify this fact to the parent.
363 * For now we take the max of all the upstream elements so the simple
364 * cases work at least somewhat.
367 gst_adder_query_duration (GstAdder * adder, GstQuery * query)
376 gst_query_parse_duration (query, &format, NULL);
382 it = gst_element_iterate_sink_pads (GST_ELEMENT_CAST (adder));
384 GstIteratorResult ires;
388 ires = gst_iterator_next (it, &item);
390 case GST_ITERATOR_DONE:
393 case GST_ITERATOR_OK:
395 GstPad *pad = GST_PAD_CAST (item);
399 /* ask sink peer for duration */
400 res &= gst_pad_query_peer_duration (pad, &format, &duration);
401 /* take max from all valid return values */
403 /* valid unknown length, stop searching */
404 if (duration == -1) {
408 /* else see if bigger than current max */
409 else if (duration > max)
412 gst_object_unref (pad);
415 case GST_ITERATOR_RESYNC:
418 gst_iterator_resync (it);
426 gst_iterator_free (it);
429 /* and store the max */
430 GST_DEBUG_OBJECT (adder, "Total duration in format %s: %"
431 GST_TIME_FORMAT, gst_format_get_name (format), GST_TIME_ARGS (max));
432 gst_query_set_duration (query, format, max);
439 gst_adder_query_latency (GstAdder * adder, GstQuery * query)
441 GstClockTime min, max;
452 max = GST_CLOCK_TIME_NONE;
454 /* Take maximum of all latency values */
455 it = gst_element_iterate_sink_pads (GST_ELEMENT_CAST (adder));
457 GstIteratorResult ires;
461 ires = gst_iterator_next (it, &item);
463 case GST_ITERATOR_DONE:
466 case GST_ITERATOR_OK:
468 GstPad *pad = GST_PAD_CAST (item);
470 GstClockTime min_cur, max_cur;
473 peerquery = gst_query_new_latency ();
475 /* Ask peer for latency */
476 res &= gst_pad_peer_query (pad, peerquery);
478 /* take max from all valid return values */
480 gst_query_parse_latency (peerquery, &live_cur, &min_cur, &max_cur);
485 if (max_cur != GST_CLOCK_TIME_NONE &&
486 ((max != GST_CLOCK_TIME_NONE && max_cur > max) ||
487 (max == GST_CLOCK_TIME_NONE)))
490 live = live || live_cur;
493 gst_query_unref (peerquery);
494 gst_object_unref (pad);
497 case GST_ITERATOR_RESYNC:
500 max = GST_CLOCK_TIME_NONE;
502 gst_iterator_resync (it);
510 gst_iterator_free (it);
513 /* store the results */
514 GST_DEBUG_OBJECT (adder, "Calculated total latency: live %s, min %"
515 GST_TIME_FORMAT ", max %" GST_TIME_FORMAT,
516 (live ? "yes" : "no"), GST_TIME_ARGS (min), GST_TIME_ARGS (max));
517 gst_query_set_latency (query, live, min, max);
524 gst_adder_query (GstPad * pad, GstQuery * query)
526 GstAdder *adder = GST_ADDER (gst_pad_get_parent (pad));
527 gboolean res = FALSE;
529 switch (GST_QUERY_TYPE (query)) {
530 case GST_QUERY_POSITION:
534 gst_query_parse_position (query, &format, NULL);
537 case GST_FORMAT_TIME:
538 /* FIXME, bring to stream time, might be tricky */
539 gst_query_set_position (query, format, adder->timestamp);
542 case GST_FORMAT_DEFAULT:
543 gst_query_set_position (query, format, adder->offset);
551 case GST_QUERY_DURATION:
552 res = gst_adder_query_duration (adder, query);
554 case GST_QUERY_LATENCY:
555 res = gst_adder_query_latency (adder, query);
558 /* FIXME, needs a custom query handler because we have multiple
560 res = gst_pad_query_default (pad, query);
564 gst_object_unref (adder);
569 forward_event_func (GstPad * pad, GValue * ret, GstEvent * event)
571 gst_event_ref (event);
572 GST_LOG_OBJECT (pad, "About to send event %s", GST_EVENT_TYPE_NAME (event));
573 if (!gst_pad_push_event (pad, event)) {
574 g_value_set_boolean (ret, FALSE);
575 GST_WARNING_OBJECT (pad, "Sending event %p (%s) failed.",
576 event, GST_EVENT_TYPE_NAME (event));
578 GST_LOG_OBJECT (pad, "Sent event %p (%s).",
579 event, GST_EVENT_TYPE_NAME (event));
581 gst_object_unref (pad);
585 /* forwards the event to all sinkpads, takes ownership of the
588 * Returns: TRUE if the event could be forwarded on all
592 forward_event (GstAdder * adder, GstEvent * event)
598 GST_LOG_OBJECT (adder, "Forwarding event %p (%s)", event,
599 GST_EVENT_TYPE_NAME (event));
603 g_value_init (&vret, G_TYPE_BOOLEAN);
604 g_value_set_boolean (&vret, TRUE);
605 it = gst_element_iterate_sink_pads (GST_ELEMENT_CAST (adder));
606 gst_iterator_fold (it, (GstIteratorFoldFunction) forward_event_func, &vret,
608 gst_iterator_free (it);
609 gst_event_unref (event);
611 ret = g_value_get_boolean (&vret);
617 gst_adder_src_event (GstPad * pad, GstEvent * event)
622 adder = GST_ADDER (gst_pad_get_parent (pad));
624 switch (GST_EVENT_TYPE (event)) {
626 /* QoS might be tricky */
635 /* parse the seek parameters */
636 gst_event_parse_seek (event, &adder->segment_rate, NULL, &flags, &curtype,
639 /* check if we are flushing */
640 if (flags & GST_SEEK_FLAG_FLUSH) {
641 /* make sure we accept nothing anymore and return WRONG_STATE */
642 gst_collect_pads_set_flushing (adder->collect, TRUE);
644 /* flushing seek, start flush downstream, the flush will be done
645 * when all pads received a FLUSH_STOP. */
646 gst_pad_push_event (adder->srcpad, gst_event_new_flush_start ());
648 /* now wait for the collected to be finished and mark a new
650 GST_OBJECT_LOCK (adder->collect);
651 if (curtype == GST_SEEK_TYPE_SET)
652 adder->segment_position = cur;
654 adder->segment_position = 0;
655 adder->segment_pending = TRUE;
656 GST_OBJECT_UNLOCK (adder->collect);
658 result = forward_event (adder, event);
661 case GST_EVENT_NAVIGATION:
662 /* navigation is rather pointless. */
666 /* just forward the rest for now */
667 result = forward_event (adder, event);
670 gst_object_unref (adder);
676 gst_adder_sink_event (GstPad * pad, GstEvent * event)
681 adder = GST_ADDER (gst_pad_get_parent (pad));
683 GST_DEBUG ("Got %s event on pad %s:%s", GST_EVENT_TYPE_NAME (event),
684 GST_DEBUG_PAD_NAME (pad));
686 switch (GST_EVENT_TYPE (event)) {
687 case GST_EVENT_FLUSH_STOP:
688 /* mark a pending new segment. This event is synchronized
689 * with the streaming thread so we can safely update the
690 * variable without races. It's somewhat weird because we
691 * assume the collectpads forwarded the FLUSH_STOP past us
692 * and downstream (using our source pad, the bastard!).
694 adder->segment_pending = TRUE;
700 /* now GstCollectPads can take care of the rest, e.g. EOS */
701 ret = adder->collect_event (pad, event);
703 gst_object_unref (adder);
708 gst_adder_class_init (GstAdderClass * klass)
710 GObjectClass *gobject_class = (GObjectClass *) klass;
711 GstElementClass *gstelement_class = (GstElementClass *) klass;
713 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_adder_finalize);
715 gst_element_class_add_pad_template (gstelement_class,
716 gst_static_pad_template_get (&gst_adder_src_template));
717 gst_element_class_add_pad_template (gstelement_class,
718 gst_static_pad_template_get (&gst_adder_sink_template));
719 gst_element_class_set_details_simple (gstelement_class, "Adder",
721 "Add N audio channels together",
722 "Thomas Vander Stichele <thomas at apestaart dot org>");
724 parent_class = g_type_class_peek_parent (klass);
726 gstelement_class->request_new_pad =
727 GST_DEBUG_FUNCPTR (gst_adder_request_new_pad);
728 gstelement_class->release_pad = GST_DEBUG_FUNCPTR (gst_adder_release_pad);
729 gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_adder_change_state);
733 gst_adder_init (GstAdder * adder)
735 GstPadTemplate *template;
737 template = gst_static_pad_template_get (&gst_adder_src_template);
738 adder->srcpad = gst_pad_new_from_template (template, "src");
739 gst_object_unref (template);
741 gst_pad_set_getcaps_function (adder->srcpad,
742 GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
743 gst_pad_set_setcaps_function (adder->srcpad,
744 GST_DEBUG_FUNCPTR (gst_adder_setcaps));
745 gst_pad_set_query_function (adder->srcpad,
746 GST_DEBUG_FUNCPTR (gst_adder_query));
747 gst_pad_set_event_function (adder->srcpad,
748 GST_DEBUG_FUNCPTR (gst_adder_src_event));
749 gst_element_add_pad (GST_ELEMENT (adder), adder->srcpad);
751 adder->format = GST_ADDER_FORMAT_UNSET;
755 /* keep track of the sinkpads requested */
756 adder->collect = gst_collect_pads_new ();
757 gst_collect_pads_set_function (adder->collect,
758 GST_DEBUG_FUNCPTR (gst_adder_collected), adder);
762 gst_adder_finalize (GObject * object)
764 GstAdder *adder = GST_ADDER (object);
766 gst_object_unref (adder->collect);
767 adder->collect = NULL;
769 G_OBJECT_CLASS (parent_class)->finalize (object);
773 gst_adder_request_new_pad (GstElement * element, GstPadTemplate * templ,
774 const gchar * unused)
781 if (templ->direction != GST_PAD_SINK)
784 adder = GST_ADDER (element);
786 /* increment pad counter */
787 padcount = g_atomic_int_exchange_and_add (&adder->padcount, 1);
789 name = g_strdup_printf ("sink%d", padcount);
790 newpad = gst_pad_new_from_template (templ, name);
791 GST_DEBUG_OBJECT (adder, "request new pad %s", name);
794 gst_pad_set_getcaps_function (newpad,
795 GST_DEBUG_FUNCPTR (gst_adder_sink_getcaps));
796 gst_pad_set_setcaps_function (newpad, GST_DEBUG_FUNCPTR (gst_adder_setcaps));
797 gst_collect_pads_add_pad (adder->collect, newpad, sizeof (GstCollectData));
799 /* FIXME: hacked way to override/extend the event function of
800 * GstCollectPads; because it sets its own event function giving the
801 * element no access to events */
802 adder->collect_event = (GstPadEventFunction) GST_PAD_EVENTFUNC (newpad);
803 gst_pad_set_event_function (newpad, GST_DEBUG_FUNCPTR (gst_adder_sink_event));
805 /* takes ownership of the pad */
806 if (!gst_element_add_pad (GST_ELEMENT (adder), newpad))
814 g_warning ("gstadder: request new pad that is not a SINK pad\n");
819 GST_DEBUG_OBJECT (adder, "could not add pad");
820 gst_collect_pads_remove_pad (adder->collect, newpad);
821 gst_object_unref (newpad);
827 gst_adder_release_pad (GstElement * element, GstPad * pad)
831 adder = GST_ADDER (element);
833 GST_DEBUG_OBJECT (adder, "release pad %s:%s", GST_DEBUG_PAD_NAME (pad));
835 gst_collect_pads_remove_pad (adder->collect, pad);
836 gst_element_remove_pad (element, pad);
840 gst_adder_collected (GstCollectPads * pads, gpointer user_data)
843 * combine streams by adding data values
845 * - this function is called when all pads have a buffer
846 * - get available bytes on all pads.
847 * - repeat for each input pad :
848 * - read available bytes, copy or add to target buffer
849 * - if there's an EOS event, remove the input channel
850 * - push out the output buffer
853 * - would be nice to have a mixing mode, where instead of adding we mix
854 * - for float we could downscale after collect loop
855 * - for int we need to downscale each input to avoid clipping or
856 * mix into a temp (float) buffer and scale afterwards as well
861 GstBuffer *outbuf = NULL;
862 gpointer outdata = NULL;
864 gboolean empty = TRUE;
866 adder = GST_ADDER (user_data);
869 if (G_UNLIKELY (adder->func == NULL))
872 /* get available bytes for reading, this can be 0 which could mean empty
873 * buffers or EOS, which we will catch when we loop over the pads. */
874 outsize = gst_collect_pads_available (pads);
876 GST_LOG_OBJECT (adder,
877 "starting to cycle through channels, %d bytes available (bps = %d)",
878 outsize, adder->bps);
880 for (collected = pads->data; collected; collected = g_slist_next (collected)) {
881 GstCollectData *collect_data;
886 collect_data = (GstCollectData *) collected->data;
888 /* get a subbuffer of size bytes */
889 inbuf = gst_collect_pads_take_buffer (pads, collect_data, outsize);
890 /* NULL means EOS or an empty buffer so we still need to flush in
891 * case of an empty buffer. */
893 GST_LOG_OBJECT (adder, "channel %p: no bytes available", collect_data);
897 indata = GST_BUFFER_DATA (inbuf);
898 insize = GST_BUFFER_SIZE (inbuf);
900 if (outbuf == NULL) {
901 GST_LOG_OBJECT (adder, "channel %p: making output buffer of %d bytes",
902 collect_data, outsize);
904 /* first buffer, alloc outsize.
905 * FIXME: we can easily subbuffer and _make_writable.
906 * FIXME: only create empty buffer for first non-gap buffer, so that we
907 * only use adder function when really adding
909 outbuf = gst_buffer_new_and_alloc (outsize);
910 outdata = GST_BUFFER_DATA (outbuf);
911 gst_buffer_set_caps (outbuf, GST_PAD_CAPS (adder->srcpad));
913 if (!GST_BUFFER_FLAG_IS_SET (inbuf, GST_BUFFER_FLAG_GAP)) {
914 GST_LOG_OBJECT (adder, "channel %p: copying %d bytes from data %p",
915 collect_data, insize, indata);
916 /* clear if we are only going to fill a partial buffer */
917 if (G_UNLIKELY (outsize > insize))
918 memset ((guint8 *) outdata + insize, 0, outsize - insize);
919 /* and copy the data into it */
920 memcpy (outdata, indata, insize);
923 /* clear whole buffer */
924 GST_LOG_OBJECT (adder, "channel %p: zeroing %d bytes from data %p",
925 collect_data, insize, indata);
926 memset (outdata, 0, outsize);
929 if (!GST_BUFFER_FLAG_IS_SET (inbuf, GST_BUFFER_FLAG_GAP)) {
930 GST_LOG_OBJECT (adder, "channel %p: mixing %d bytes from data %p",
931 collect_data, insize, indata);
932 /* further buffers, need to add them */
933 adder->func ((gpointer) outdata, (gpointer) indata, insize);
936 GST_LOG_OBJECT (adder, "channel %p: skipping %d bytes from data %p",
937 collect_data, insize, indata);
940 gst_buffer_unref (inbuf);
943 /* can only happen when no pads to collect or all EOS */
947 /* our timestamping is very simple, just an ever incrementing
948 * counter, the new segment time will take care of their respective
950 if (adder->segment_pending) {
953 /* FIXME, use rate/applied_rate as set on all sinkpads.
954 * - currently we just set rate as received from last seek-event
955 * We could potentially figure out the duration as well using
956 * the current segment positions and the stated stop positions.
957 * Also we just start from stream time 0 which is rather
958 * weird. For non-synchronized mixing, the time should be
959 * the min of the stream times of all received segments,
960 * rationale being that the duration is at least going to
961 * be as long as the earliest stream we start mixing. This
962 * would also be correct for synchronized mixing but then
963 * the later streams would be delayed until the stream times
966 event = gst_event_new_new_segment_full (FALSE, adder->segment_rate,
967 1.0, GST_FORMAT_TIME, adder->timestamp, -1, adder->segment_position);
969 gst_pad_push_event (adder->srcpad, event);
970 adder->segment_pending = FALSE;
971 adder->segment_position = 0;
974 /* set timestamps on the output buffer */
975 GST_BUFFER_TIMESTAMP (outbuf) = adder->timestamp;
976 GST_BUFFER_OFFSET (outbuf) = adder->offset;
978 /* for the next timestamp, use the sample counter, which will
979 * never accumulate rounding errors */
980 adder->offset += outsize / adder->bps;
981 adder->timestamp = gst_util_uint64_scale_int (adder->offset,
982 GST_SECOND, adder->rate);
984 /* now we can set the duration of the buffer */
985 GST_BUFFER_DURATION (outbuf) = adder->timestamp -
986 GST_BUFFER_TIMESTAMP (outbuf);
988 /* if we only processed silence, mark output again as silence */
990 GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_GAP);
993 GST_LOG_OBJECT (adder, "pushing outbuf, timestamp %" GST_TIME_FORMAT,
994 GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)));
995 ret = gst_pad_push (adder->srcpad, outbuf);
1002 GST_ELEMENT_ERROR (adder, STREAM, FORMAT, (NULL),
1003 ("Unknown data received, not negotiated"));
1004 return GST_FLOW_NOT_NEGOTIATED;
1008 GST_DEBUG_OBJECT (adder, "no data available, must be EOS");
1009 gst_pad_push_event (adder->srcpad, gst_event_new_eos ());
1010 return GST_FLOW_UNEXPECTED;
1014 static GstStateChangeReturn
1015 gst_adder_change_state (GstElement * element, GstStateChange transition)
1018 GstStateChangeReturn ret;
1020 adder = GST_ADDER (element);
1022 switch (transition) {
1023 case GST_STATE_CHANGE_NULL_TO_READY:
1025 case GST_STATE_CHANGE_READY_TO_PAUSED:
1026 adder->timestamp = 0;
1028 adder->segment_pending = TRUE;
1029 adder->segment_position = 0;
1030 adder->segment_rate = 1.0;
1031 gst_segment_init (&adder->segment, GST_FORMAT_UNDEFINED);
1032 gst_collect_pads_start (adder->collect);
1034 case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
1036 case GST_STATE_CHANGE_PAUSED_TO_READY:
1037 /* need to unblock the collectpads before calling the
1038 * parent change_state so that streaming can finish */
1039 gst_collect_pads_stop (adder->collect);
1045 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
1047 switch (transition) {
1057 plugin_init (GstPlugin * plugin)
1061 if (!gst_element_register (plugin, "adder", GST_RANK_NONE, GST_TYPE_ADDER)) {
1068 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
1071 "Adds multiple streams",
1072 plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)