--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_base/gst/adder/gstadder.c Thu Dec 17 08:53:32 2009 +0200
@@ -0,0 +1,930 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ * 2001 Thomas <thomas@apestaart.org>
+ * 2005,2006 Wim Taymans <wim@fluendo.com>
+ *
+ * adder.c: Adder element, N in, one out, samples are added
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+/**
+ * SECTION:element-adder
+ *
+ * <refsect2>
+ * <para>
+ * The Adder allows to mix several streams into one by adding the data.
+ * Mixed data is clamped to the min/max values of the data format.
+ * </para>
+ * <title>Example launch line</title>
+ * <para>
+ * <programlisting>
+ * gst-launch audiotestsrc freq=100 ! adder name=mix ! audioconvert ! alsasink audiotestsrc freq=500 ! mix.
+ * </programlisting>
+ * This pipeline produces two sine waves mixed together.
+ * </para>
+ * <para>
+ * The Adder currently mixes all data received on the sinkpads as soon as possible
+ * without trying to synchronize the streams.
+ * </para>
+ * </refsect2>
+ *
+ * Last reviewed on 2006-05-09 (0.10.7)
+ */
+/* Element-Checklist-Version: 5 */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "gstadder.h"
+#include <gst/audio/audio.h>
+#include <string.h> /* strcmp */
+
+#ifdef __SYMBIAN32__
+#include <glib_global.h>
+#endif
+
+/* highest positive/lowest negative x-bit value we can use for clamping */
+#define MAX_INT_32 ((gint32) (0x7fffffff))
+#define MAX_INT_16 ((gint16) (0x7fff))
+#define MAX_INT_8 ((gint8) (0x7f))
+#define MAX_UINT_32 ((guint32)(0xffffffff))
+#define MAX_UINT_16 ((guint16)(0xffff))
+#define MAX_UINT_8 ((guint8) (0xff))
+
+#define MIN_INT_32 ((gint32) (0x80000000))
+#define MIN_INT_16 ((gint16) (0x8000))
+#define MIN_INT_8 ((gint8) (0x80))
+#define MIN_UINT_32 ((guint32)(0x00000000))
+#define MIN_UINT_16 ((guint16)(0x0000))
+#define MIN_UINT_8 ((guint8) (0x00))
+
+#define GST_CAT_DEFAULT gst_adder_debug
+GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
+
+/* elementfactory information */
+static const GstElementDetails adder_details = GST_ELEMENT_DETAILS ("Adder",
+ "Generic/Audio",
+ "Add N audio channels together",
+ "Thomas <thomas@apestaart.org>");
+
+static GstStaticPadTemplate gst_adder_src_template =
+ GST_STATIC_PAD_TEMPLATE ("src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS (GST_AUDIO_INT_PAD_TEMPLATE_CAPS "; "
+ GST_AUDIO_FLOAT_PAD_TEMPLATE_CAPS)
+ );
+
+static GstStaticPadTemplate gst_adder_sink_template =
+ GST_STATIC_PAD_TEMPLATE ("sink%d",
+ GST_PAD_SINK,
+ GST_PAD_REQUEST,
+ GST_STATIC_CAPS (GST_AUDIO_INT_PAD_TEMPLATE_CAPS "; "
+ GST_AUDIO_FLOAT_PAD_TEMPLATE_CAPS)
+ );
+
+static void gst_adder_class_init (GstAdderClass * klass);
+static void gst_adder_init (GstAdder * adder);
+static void gst_adder_finalize (GObject * object);
+
+static gboolean gst_adder_setcaps (GstPad * pad, GstCaps * caps);
+static gboolean gst_adder_query (GstPad * pad, GstQuery * query);
+static gboolean gst_adder_src_event (GstPad * pad, GstEvent * event);
+static gboolean gst_adder_sink_event (GstPad * pad, GstEvent * event);
+
+static GstPad *gst_adder_request_new_pad (GstElement * element,
+ GstPadTemplate * temp, const gchar * unused);
+static void gst_adder_release_pad (GstElement * element, GstPad * pad);
+
+static GstStateChangeReturn gst_adder_change_state (GstElement * element,
+ GstStateChange transition);
+
+static GstFlowReturn gst_adder_collected (GstCollectPads * pads,
+ gpointer user_data);
+
+static GstElementClass *parent_class = NULL;
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GType
+gst_adder_get_type (void)
+{
+ static GType adder_type = 0;
+
+ if (G_UNLIKELY (adder_type == 0)) {
+ static const GTypeInfo adder_info = {
+ sizeof (GstAdderClass), NULL, NULL,
+ (GClassInitFunc) gst_adder_class_init, NULL, NULL,
+ sizeof (GstAdder), 0,
+ (GInstanceInitFunc) gst_adder_init,
+ };
+
+ adder_type = g_type_register_static (GST_TYPE_ELEMENT, "GstAdder",
+ &adder_info, 0);
+ GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "adder", 0,
+ "audio channel mixing element");
+ }
+ return adder_type;
+}
+
+/* clipping versions */
+#define MAKE_FUNC(name,type,ttype,min,max) \
+static void name (type *out, type *in, gint bytes) { \
+ gint i; \
+ for (i = 0; i < bytes / sizeof (type); i++) \
+ out[i] = CLAMP ((ttype)out[i] + (ttype)in[i], min, max); \
+}
+
+/* non-clipping versions (for float) */
+#define MAKE_FUNC_NC(name,type,ttype) \
+static void name (type *out, type *in, gint bytes) { \
+ gint i; \
+ for (i = 0; i < bytes / sizeof (type); i++) \
+ out[i] = (ttype)out[i] + (ttype)in[i]; \
+}
+
+/* *INDENT-OFF* */
+MAKE_FUNC (add_int32, gint32, gint64, MIN_INT_32, MAX_INT_32)
+MAKE_FUNC (add_int16, gint16, gint32, MIN_INT_16, MAX_INT_16)
+MAKE_FUNC (add_int8, gint8, gint16, MIN_INT_8, MAX_INT_8)
+MAKE_FUNC (add_uint32, guint32, guint64, MIN_UINT_32, MAX_UINT_32)
+MAKE_FUNC (add_uint16, guint16, guint32, MIN_UINT_16, MAX_UINT_16)
+MAKE_FUNC (add_uint8, guint8, guint16, MIN_UINT_8, MAX_UINT_8)
+MAKE_FUNC_NC (add_float64, gdouble, gdouble)
+MAKE_FUNC_NC (add_float32, gfloat, gfloat)
+/* *INDENT-ON* */
+
+/* we can only accept caps that we and downstream can handle. */
+static GstCaps *
+gst_adder_sink_getcaps (GstPad * pad)
+{
+ GstAdder *adder;
+ GstCaps *result, *peercaps, *sinkcaps;
+
+ adder = GST_ADDER (GST_PAD_PARENT (pad));
+
+ GST_OBJECT_LOCK (adder);
+ /* get the downstream possible caps */
+ peercaps = gst_pad_peer_get_caps (adder->srcpad);
+ /* get the allowed caps on this sinkpad, we use the fixed caps function so
+ * that it does not call recursively in this function. */
+ sinkcaps = gst_pad_get_fixed_caps_func (pad);
+ if (peercaps) {
+ /* if the peer has caps, intersect */
+ GST_DEBUG_OBJECT (adder, "intersecting peer and template caps");
+ result = gst_caps_intersect (peercaps, sinkcaps);
+ gst_caps_unref (peercaps);
+ gst_caps_unref (sinkcaps);
+ } else {
+ /* the peer has no caps (or there is no peer), just use the allowed caps
+ * of this sinkpad. */
+ GST_DEBUG_OBJECT (adder, "no peer caps, using sinkcaps");
+ result = sinkcaps;
+ }
+ GST_OBJECT_UNLOCK (adder);
+
+ return result;
+}
+
+/* the first caps we receive on any of the sinkpads will define the caps for all
+ * the other sinkpads because we can only mix streams with the same caps.
+ * */
+static gboolean
+gst_adder_setcaps (GstPad * pad, GstCaps * caps)
+{
+ GstAdder *adder;
+ GList *pads;
+ GstStructure *structure;
+ const char *media_type;
+
+ adder = GST_ADDER (GST_PAD_PARENT (pad));
+
+ GST_LOG_OBJECT (adder, "setting caps on pad %p,%s to %" GST_PTR_FORMAT, pad,
+ GST_PAD_NAME (pad), caps);
+
+ /* FIXME, see if the other pads can accept the format. Also lock the
+ * format on the other pads to this new format. */
+ GST_OBJECT_LOCK (adder);
+ pads = GST_ELEMENT (adder)->pads;
+ while (pads) {
+ GstPad *otherpad = GST_PAD (pads->data);
+
+ if (otherpad != pad) {
+ gst_caps_replace (&GST_PAD_CAPS (otherpad), caps);
+ }
+ pads = g_list_next (pads);
+ }
+ GST_OBJECT_UNLOCK (adder);
+
+ /* parse caps now */
+ structure = gst_caps_get_structure (caps, 0);
+ media_type = gst_structure_get_name (structure);
+ if (strcmp (media_type, "audio/x-raw-int") == 0) {
+ GST_DEBUG_OBJECT (adder, "parse_caps sets adder to format int");
+ adder->format = GST_ADDER_FORMAT_INT;
+ gst_structure_get_int (structure, "width", &adder->width);
+ gst_structure_get_int (structure, "depth", &adder->depth);
+ gst_structure_get_int (structure, "endianness", &adder->endianness);
+ gst_structure_get_boolean (structure, "signed", &adder->is_signed);
+
+ if (adder->endianness != G_BYTE_ORDER)
+ goto not_supported;
+
+ switch (adder->width) {
+ case 8:
+ adder->func = (adder->is_signed ?
+ (GstAdderFunction) add_int8 : (GstAdderFunction) add_uint8);
+ break;
+ case 16:
+ adder->func = (adder->is_signed ?
+ (GstAdderFunction) add_int16 : (GstAdderFunction) add_uint16);
+ break;
+ case 32:
+ adder->func = (adder->is_signed ?
+ (GstAdderFunction) add_int32 : (GstAdderFunction) add_uint32);
+ break;
+ default:
+ goto not_supported;
+ }
+ } else if (strcmp (media_type, "audio/x-raw-float") == 0) {
+ GST_DEBUG_OBJECT (adder, "parse_caps sets adder to format float");
+ adder->format = GST_ADDER_FORMAT_FLOAT;
+ gst_structure_get_int (structure, "width", &adder->width);
+
+ switch (adder->width) {
+ case 32:
+ adder->func = (GstAdderFunction) add_float32;
+ break;
+ case 64:
+ adder->func = (GstAdderFunction) add_float64;
+ break;
+ default:
+ goto not_supported;
+ }
+ } else {
+ goto not_supported;
+ }
+
+ gst_structure_get_int (structure, "channels", &adder->channels);
+ gst_structure_get_int (structure, "rate", &adder->rate);
+ /* precalc bps */
+ adder->bps = (adder->width / 8) * adder->channels;
+
+ return TRUE;
+
+ /* ERRORS */
+not_supported:
+ {
+ GST_DEBUG_OBJECT (adder, "unsupported format set as caps");
+ return FALSE;
+ }
+}
+
+/* FIXME, the duration query should reflect how long you will produce
+ * data, that is the amount of stream time until you will emit EOS.
+ *
+ * For synchronized mixing this is always the max of all the durations
+ * of upstream since we emit EOS when all of them finished.
+ *
+ * We don't do synchronized mixing so this really depends on where the
+ * streams where punched in and what their relative offsets are against
+ * eachother which we can get from the first timestamps we see.
+ *
+ * When we add a new stream (or remove a stream) the duration might
+ * also become invalid again and we need to post a new DURATION
+ * message to notify this fact to the parent.
+ * For now we take the max of all the upstream elements so the simple
+ * cases work at least somewhat.
+ */
+static gboolean
+gst_adder_query_duration (GstAdder * adder, GstQuery * query)
+{
+ gint64 max;
+ gboolean res;
+ GstFormat format;
+ GstIterator *it;
+ gboolean done;
+
+ /* parse format */
+ gst_query_parse_duration (query, &format, NULL);
+
+ max = -1;
+ res = TRUE;
+ done = FALSE;
+
+ it = gst_element_iterate_sink_pads (GST_ELEMENT_CAST (adder));
+ while (!done) {
+ GstIteratorResult ires;
+ gpointer item;
+
+ ires = gst_iterator_next (it, &item);
+ switch (ires) {
+ case GST_ITERATOR_DONE:
+ done = TRUE;
+ break;
+ case GST_ITERATOR_OK:
+ {
+ GstPad *pad = GST_PAD_CAST (item);
+ gint64 duration;
+
+ /* ask sink peer for duration */
+ res &= gst_pad_query_peer_duration (pad, &format, &duration);
+ /* take max from all valid return values */
+ if (res) {
+ /* valid unknown length, stop searching */
+ if (duration == -1) {
+ max = duration;
+ done = TRUE;
+ }
+ /* else see if bigger than current max */
+ else if (duration > max)
+ max = duration;
+ }
+ break;
+ }
+ case GST_ITERATOR_RESYNC:
+ max = -1;
+ res = TRUE;
+ break;
+ default:
+ res = FALSE;
+ done = TRUE;
+ break;
+ }
+ }
+ gst_iterator_free (it);
+
+ if (res) {
+ /* and store the max */
+ gst_query_set_duration (query, format, max);
+ }
+
+ return res;
+}
+
+static gboolean
+gst_adder_query (GstPad * pad, GstQuery * query)
+{
+ GstAdder *adder = GST_ADDER (gst_pad_get_parent (pad));
+ gboolean res = FALSE;
+
+ switch (GST_QUERY_TYPE (query)) {
+ case GST_QUERY_POSITION:
+ {
+ GstFormat format;
+
+ gst_query_parse_position (query, &format, NULL);
+
+ switch (format) {
+ case GST_FORMAT_TIME:
+ /* FIXME, bring to stream time, might be tricky */
+ gst_query_set_position (query, format, adder->timestamp);
+ res = TRUE;
+ break;
+ case GST_FORMAT_DEFAULT:
+ gst_query_set_position (query, format, adder->offset);
+ res = TRUE;
+ break;
+ default:
+ break;
+ }
+ break;
+ }
+ case GST_QUERY_DURATION:
+ res = gst_adder_query_duration (adder, query);
+ break;
+ default:
+ /* FIXME, needs a custom query handler because we have multiple
+ * sinkpads */
+ res = gst_pad_query_default (pad, query);
+ break;
+ }
+
+ gst_object_unref (adder);
+ return res;
+}
+
+static gboolean
+forward_event_func (GstPad * pad, GValue * ret, GstEvent * event)
+{
+ gst_event_ref (event);
+ GST_LOG_OBJECT (pad, "About to send event %s", GST_EVENT_TYPE_NAME (event));
+ if (!gst_pad_push_event (pad, event)) {
+ g_value_set_boolean (ret, FALSE);
+ GST_WARNING_OBJECT (pad, "Sending event %p (%s) failed.",
+ event, GST_EVENT_TYPE_NAME (event));
+ } else {
+ GST_LOG_OBJECT (pad, "Sent event %p (%s).",
+ event, GST_EVENT_TYPE_NAME (event));
+ }
+ gst_object_unref (pad);
+ return TRUE;
+}
+
+/* forwards the event to all sinkpads, takes ownership of the
+ * event
+ *
+ * Returns: TRUE if the event could be forwarded on all
+ * sinkpads.
+ */
+static gboolean
+forward_event (GstAdder * adder, GstEvent * event)
+{
+ gboolean ret;
+ GstIterator *it;
+ GValue vret = { 0 };
+
+ GST_LOG_OBJECT (adder, "Forwarding event %p (%s)", event,
+ GST_EVENT_TYPE_NAME (event));
+
+ ret = TRUE;
+
+ g_value_init (&vret, G_TYPE_BOOLEAN);
+ g_value_set_boolean (&vret, TRUE);
+ it = gst_element_iterate_sink_pads (GST_ELEMENT_CAST (adder));
+ gst_iterator_fold (it, (GstIteratorFoldFunction) forward_event_func, &vret,
+ event);
+ gst_iterator_free (it);
+ gst_event_unref (event);
+
+ ret = g_value_get_boolean (&vret);
+
+ return ret;
+}
+
+static gboolean
+gst_adder_src_event (GstPad * pad, GstEvent * event)
+{
+ GstAdder *adder;
+ gboolean result;
+
+ adder = GST_ADDER (gst_pad_get_parent (pad));
+
+ switch (GST_EVENT_TYPE (event)) {
+ case GST_EVENT_QOS:
+ /* QoS might be tricky */
+ result = FALSE;
+ break;
+ case GST_EVENT_SEEK:
+ {
+ GstSeekFlags flags;
+ GstSeekType curtype;
+ gint64 cur;
+
+ /* parse the seek parameters */
+ gst_event_parse_seek (event, &adder->segment_rate, NULL, &flags, &curtype,
+ &cur, NULL, NULL);
+
+ /* check if we are flushing */
+ if (flags & GST_SEEK_FLAG_FLUSH) {
+ /* make sure we accept nothing anymore and return WRONG_STATE */
+ gst_collect_pads_set_flushing (adder->collect, TRUE);
+
+ /* flushing seek, start flush downstream, the flush will be done
+ * when all pads received a FLUSH_STOP. */
+ gst_pad_push_event (adder->srcpad, gst_event_new_flush_start ());
+ }
+
+ /* now wait for the collected to be finished and mark a new
+ * segment */
+ GST_OBJECT_LOCK (adder->collect);
+ if (curtype == GST_SEEK_TYPE_SET)
+ adder->segment_position = cur;
+ else
+ adder->segment_position = 0;
+ adder->segment_pending = TRUE;
+ GST_OBJECT_UNLOCK (adder->collect);
+
+ result = forward_event (adder, event);
+ break;
+ }
+ case GST_EVENT_NAVIGATION:
+ /* navigation is rather pointless. */
+ result = FALSE;
+ break;
+ default:
+ /* just forward the rest for now */
+ result = forward_event (adder, event);
+ break;
+ }
+ gst_object_unref (adder);
+
+ return result;
+}
+
+static gboolean
+gst_adder_sink_event (GstPad * pad, GstEvent * event)
+{
+ GstAdder *adder;
+ gboolean ret;
+
+ adder = GST_ADDER (gst_pad_get_parent (pad));
+
+ GST_DEBUG ("Got %s event on pad %s:%s", GST_EVENT_TYPE_NAME (event),
+ GST_DEBUG_PAD_NAME (pad));
+
+ switch (GST_EVENT_TYPE (event)) {
+ case GST_EVENT_FLUSH_STOP:
+ /* mark a pending new segment. This event is synchronized
+ * with the streaming thread so we can safely update the
+ * variable without races. It's somewhat weird because we
+ * assume the collectpads forwarded the FLUSH_STOP past us
+ * and downstream (using our source pad, the bastard!).
+ */
+ adder->segment_pending = TRUE;
+ break;
+ default:
+ break;
+ }
+
+ /* now GstCollectPads can take care of the rest, e.g. EOS */
+ ret = adder->collect_event (pad, event);
+
+ gst_object_unref (adder);
+ return ret;
+}
+
+static void
+gst_adder_class_init (GstAdderClass * klass)
+{
+ GObjectClass *gobject_class;
+ GstElementClass *gstelement_class;
+
+ gobject_class = (GObjectClass *) klass;
+
+ gobject_class->finalize = gst_adder_finalize;
+
+ gstelement_class = (GstElementClass *) klass;
+
+ gst_element_class_add_pad_template (gstelement_class,
+ gst_static_pad_template_get (&gst_adder_src_template));
+ gst_element_class_add_pad_template (gstelement_class,
+ gst_static_pad_template_get (&gst_adder_sink_template));
+ gst_element_class_set_details (gstelement_class, &adder_details);
+
+ parent_class = g_type_class_peek_parent (klass);
+
+ gstelement_class->request_new_pad = gst_adder_request_new_pad;
+ gstelement_class->release_pad = gst_adder_release_pad;
+ gstelement_class->change_state = gst_adder_change_state;
+}
+
+static void
+gst_adder_init (GstAdder * adder)
+{
+ GstPadTemplate *template;
+
+ template = gst_static_pad_template_get (&gst_adder_src_template);
+ adder->srcpad = gst_pad_new_from_template (template, "src");
+ gst_object_unref (template);
+ gst_pad_set_getcaps_function (adder->srcpad,
+ GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
+ gst_pad_set_setcaps_function (adder->srcpad,
+ GST_DEBUG_FUNCPTR (gst_adder_setcaps));
+ gst_pad_set_query_function (adder->srcpad,
+ GST_DEBUG_FUNCPTR (gst_adder_query));
+ gst_pad_set_event_function (adder->srcpad,
+ GST_DEBUG_FUNCPTR (gst_adder_src_event));
+ gst_element_add_pad (GST_ELEMENT (adder), adder->srcpad);
+
+ adder->format = GST_ADDER_FORMAT_UNSET;
+ adder->padcount = 0;
+ adder->func = NULL;
+
+ /* keep track of the sinkpads requested */
+ adder->collect = gst_collect_pads_new ();
+ gst_collect_pads_set_function (adder->collect,
+ GST_DEBUG_FUNCPTR (gst_adder_collected), adder);
+}
+
+static void
+gst_adder_finalize (GObject * object)
+{
+ GstAdder *adder = GST_ADDER (object);
+
+ gst_object_unref (adder->collect);
+ adder->collect = NULL;
+
+ G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static GstPad *
+gst_adder_request_new_pad (GstElement * element, GstPadTemplate * templ,
+ const gchar * unused)
+{
+ gchar *name;
+ GstAdder *adder;
+ GstPad *newpad;
+ gint padcount;
+
+ if (templ->direction != GST_PAD_SINK)
+ goto not_sink;
+
+ adder = GST_ADDER (element);
+
+ /* increment pad counter */
+ padcount = g_atomic_int_exchange_and_add (&adder->padcount, 1);
+
+ name = g_strdup_printf ("sink%d", padcount);
+ newpad = gst_pad_new_from_template (templ, name);
+ GST_DEBUG_OBJECT (adder, "request new pad %s", name);
+ g_free (name);
+
+ gst_pad_set_getcaps_function (newpad,
+ GST_DEBUG_FUNCPTR (gst_adder_sink_getcaps));
+ gst_pad_set_setcaps_function (newpad, GST_DEBUG_FUNCPTR (gst_adder_setcaps));
+ gst_collect_pads_add_pad (adder->collect, newpad, sizeof (GstCollectData));
+
+ /* FIXME: hacked way to override/extend the event function of
+ * GstCollectPads; because it sets its own event function giving the
+ * element no access to events */
+ adder->collect_event = (GstPadEventFunction) GST_PAD_EVENTFUNC (newpad);
+ gst_pad_set_event_function (newpad, GST_DEBUG_FUNCPTR (gst_adder_sink_event));
+
+ /* takes ownership of the pad */
+ if (!gst_element_add_pad (GST_ELEMENT (adder), newpad))
+ goto could_not_add;
+
+ return newpad;
+
+ /* errors */
+not_sink:
+ {
+ g_warning ("gstadder: request new pad that is not a SINK pad\n");
+ return NULL;
+ }
+could_not_add:
+ {
+ GST_DEBUG_OBJECT (adder, "could not add pad");
+ gst_collect_pads_remove_pad (adder->collect, newpad);
+ gst_object_unref (newpad);
+ return NULL;
+ }
+}
+
+static void
+gst_adder_release_pad (GstElement * element, GstPad * pad)
+{
+ GstAdder *adder;
+
+ adder = GST_ADDER (element);
+
+ GST_DEBUG_OBJECT (adder, "release pad %s:%s", GST_DEBUG_PAD_NAME (pad));
+
+ gst_collect_pads_remove_pad (adder->collect, pad);
+ gst_element_remove_pad (element, pad);
+}
+
+static GstFlowReturn
+gst_adder_collected (GstCollectPads * pads, gpointer user_data)
+{
+ /*
+ * combine channels by adding sample values
+ * basic algorithm :
+ * - this function is called when all pads have a buffer
+ * - get available bytes on all pads.
+ * - repeat for each input pad :
+ * - read available bytes, copy or add to target buffer
+ * - if there's an EOS event, remove the input channel
+ * - push out the output buffer
+ */
+ GstAdder *adder;
+ guint size;
+ GSList *collected;
+ GstBuffer *outbuf;
+ GstFlowReturn ret;
+ gpointer outbytes;
+ gboolean empty = TRUE;
+
+ adder = GST_ADDER (user_data);
+
+ /* this is fatal */
+ if (G_UNLIKELY (adder->func == NULL))
+ goto not_negotiated;
+
+ /* get available bytes for reading, this can be 0 which could mean
+ * empty buffers or EOS, which we will catch when we loop over the
+ * pads. */
+ size = gst_collect_pads_available (pads);
+
+ GST_LOG_OBJECT (adder,
+ "starting to cycle through channels, %d bytes available (bps = %d)", size,
+ adder->bps);
+
+ outbuf = NULL;
+ outbytes = NULL;
+
+ for (collected = pads->data; collected; collected = g_slist_next (collected)) {
+ GstCollectData *data;
+ guint8 *bytes;
+ guint len;
+ GstBuffer *inbuf;
+
+ data = (GstCollectData *) collected->data;
+
+ /* get a subbuffer of size bytes */
+ inbuf = gst_collect_pads_take_buffer (pads, data, size);
+ /* NULL means EOS or an empty buffer so we still need to flush in
+ * case of an empty buffer. */
+ if (inbuf == NULL) {
+ GST_LOG_OBJECT (adder, "channel %p: no bytes available", data);
+ goto next;
+ }
+
+ bytes = GST_BUFFER_DATA (inbuf);
+ len = GST_BUFFER_SIZE (inbuf);
+
+ if (outbuf == NULL) {
+ GST_LOG_OBJECT (adder, "channel %p: making output buffer of %d bytes",
+ data, size);
+
+ /* first buffer, alloc size bytes. FIXME, we can easily subbuffer
+ * and _make_writable. */
+ outbuf = gst_buffer_new_and_alloc (size);
+ outbytes = GST_BUFFER_DATA (outbuf);
+ gst_buffer_set_caps (outbuf, GST_PAD_CAPS (adder->srcpad));
+
+ if (!GST_BUFFER_FLAG_IS_SET (inbuf, GST_BUFFER_FLAG_GAP)) {
+ /* clear if we are only going to fill a partial buffer */
+ if (G_UNLIKELY (size > len))
+ memset (outbytes, 0, size);
+
+ GST_LOG_OBJECT (adder, "channel %p: copying %d bytes from data %p",
+ data, len, bytes);
+
+ /* and copy the data into it */
+ memcpy (outbytes, bytes, len);
+ empty = FALSE;
+ } else {
+ GST_LOG_OBJECT (adder, "channel %p: zeroing %d bytes from data %p",
+ data, len, bytes);
+ memset (outbytes, 0, size);
+ }
+ } else {
+ if (!GST_BUFFER_FLAG_IS_SET (inbuf, GST_BUFFER_FLAG_GAP)) {
+ GST_LOG_OBJECT (adder, "channel %p: mixing %d bytes from data %p",
+ data, len, bytes);
+ /* other buffers, need to add them */
+ adder->func ((gpointer) outbytes, (gpointer) bytes, len);
+ empty = FALSE;
+ } else {
+ GST_LOG_OBJECT (adder, "channel %p: skipping %d bytes from data %p",
+ data, len, bytes);
+ }
+ }
+ next:
+ if (inbuf)
+ gst_buffer_unref (inbuf);
+ }
+
+ /* can only happen when no pads to collect or all EOS */
+ if (outbuf == NULL)
+ goto eos;
+
+ /* our timestamping is very simple, just an ever incrementing
+ * counter, the new segment time will take care of their respective
+ * stream time. */
+ if (adder->segment_pending) {
+ GstEvent *event;
+
+ /* FIXME, use rate/applied_rate as set on all sinkpads.
+ * - currently we just set rate as received from last seek-event
+ * We could potentially figure out the duration as well using
+ * the current segment positions and the stated stop positions.
+ * Also we just start from stream time 0 which is rather
+ * weird. For non-synchronized mixing, the time should be
+ * the min of the stream times of all received segments,
+ * rationale being that the duration is at least going to
+ * be as long as the earliest stream we start mixing. This
+ * would also be correct for synchronized mixing but then
+ * the later streams would be delayed until the stream times
+ * match.
+ */
+ event = gst_event_new_new_segment_full (FALSE, adder->segment_rate,
+ 1.0, GST_FORMAT_TIME, adder->timestamp, -1, adder->segment_position);
+
+ gst_pad_push_event (adder->srcpad, event);
+ adder->segment_pending = FALSE;
+ adder->segment_position = 0;
+ }
+
+ /* set timestamps on the output buffer */
+ GST_BUFFER_TIMESTAMP (outbuf) = adder->timestamp;
+ GST_BUFFER_OFFSET (outbuf) = adder->offset;
+
+ /* for the next timestamp, use the sample counter, which will
+ * never accumulate rounding errors */
+ adder->offset += size / adder->bps;
+ adder->timestamp = gst_util_uint64_scale_int (adder->offset,
+ GST_SECOND, adder->rate);
+
+ /* now we can set the duration of the buffer */
+ GST_BUFFER_DURATION (outbuf) = adder->timestamp -
+ GST_BUFFER_TIMESTAMP (outbuf);
+
+ /* if we only processed silence, mark output again as silence */
+ if (empty)
+ GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_GAP);
+
+ /* send it out */
+ GST_LOG_OBJECT (adder, "pushing outbuf, timestamp %" GST_TIME_FORMAT,
+ GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (outbuf)));
+ ret = gst_pad_push (adder->srcpad, outbuf);
+
+ return ret;
+
+ /* ERRORS */
+not_negotiated:
+ {
+ GST_ELEMENT_ERROR (adder, STREAM, FORMAT, (NULL),
+ ("Unknown data received, not negotiated"));
+ return GST_FLOW_NOT_NEGOTIATED;
+ }
+eos:
+ {
+ GST_DEBUG_OBJECT (adder, "no data available, must be EOS");
+ gst_pad_push_event (adder->srcpad, gst_event_new_eos ());
+ return GST_FLOW_UNEXPECTED;
+ }
+}
+
+static GstStateChangeReturn
+gst_adder_change_state (GstElement * element, GstStateChange transition)
+{
+ GstAdder *adder;
+ GstStateChangeReturn ret;
+
+ adder = GST_ADDER (element);
+
+ switch (transition) {
+ case GST_STATE_CHANGE_NULL_TO_READY:
+ break;
+ case GST_STATE_CHANGE_READY_TO_PAUSED:
+ adder->timestamp = 0;
+ adder->offset = 0;
+ adder->segment_pending = TRUE;
+ adder->segment_position = 0;
+ adder->segment_rate = 1.0;
+ gst_segment_init (&adder->segment, GST_FORMAT_UNDEFINED);
+ gst_collect_pads_start (adder->collect);
+ break;
+ case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
+ break;
+ case GST_STATE_CHANGE_PAUSED_TO_READY:
+ /* need to unblock the collectpads before calling the
+ * parent change_state so that streaming can finish */
+ gst_collect_pads_stop (adder->collect);
+ break;
+ default:
+ break;
+ }
+
+ ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+ switch (transition) {
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+ if (!gst_element_register (plugin, "adder", GST_RANK_NONE, GST_TYPE_ADDER)) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+ GST_VERSION_MINOR,
+ "adder",
+ "Adds multiple streams",
+ plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);
+
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+GstPluginDesc* _GST_PLUGIN_DESC()
+{
+ return &gst_plugin_desc;
+}