X-Git-Url: http://git.maemo.org/git/?p=mafwsubrenderer;a=blobdiff_plain;f=gst-plugins-base-subtitles0.10%2Fgst-libs%2Fgst%2Frtp%2Fgstbasertppayload.c;fp=gst-plugins-base-subtitles0.10%2Fgst-libs%2Fgst%2Frtp%2Fgstbasertppayload.c;h=060e4e018857f0cbff18980eb57802d1cfda0161;hp=0000000000000000000000000000000000000000;hb=57ba96e291a055f69dbfd4ae9f1ae2390e36986e;hpb=be2c98fb83895d10ac44af7b9a9c3e00ca54bf49

diff --git a/gst-plugins-base-subtitles0.10/gst-libs/gst/rtp/gstbasertppayload.c b/gst-plugins-base-subtitles0.10/gst-libs/gst/rtp/gstbasertppayload.c
new file mode 100644
index 0000000..060e4e0
--- /dev/null
+++ b/gst-plugins-base-subtitles0.10/gst-libs/gst/rtp/gstbasertppayload.c
@@ -0,0 +1,1069 @@
+/* GStreamer
+ * Copyright (C) <2005> Wim Taymans <wim@fluendo.com>
+ *
+ * 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
+ */
+
+/**
+ * SECTION:gstbasertppayload
+ * @short_description: Base class for RTP payloader
+ *
+ * <refsect2>
+ * <para>
+ * Provides a base class for RTP payloaders
+ * </para>
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include <string.h>
+
+#include <gst/rtp/gstrtpbuffer.h>
+
+#include "gstbasertppayload.h"
+
+GST_DEBUG_CATEGORY_STATIC (basertppayload_debug);
+#define GST_CAT_DEFAULT (basertppayload_debug)
+
+#define GST_BASE_RTP_PAYLOAD_GET_PRIVATE(obj)  \
+   (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BASE_RTP_PAYLOAD, GstBaseRTPPayloadPrivate))
+
+struct _GstBaseRTPPayloadPrivate
+{
+  gboolean ts_offset_random;
+  gboolean seqnum_offset_random;
+  gboolean ssrc_random;
+  guint16 next_seqnum;
+  gboolean perfect_rtptime;
+  gint notified_first_timestamp;
+
+  gint64 prop_max_ptime;
+  gint64 caps_max_ptime;
+};
+
+/* BaseRTPPayload signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+/* FIXME 0.11, a better default is the Ethernet MTU of
+ * 1500 - sizeof(headers) as pointed out by marcelm in IRC:
+ * So an Ethernet MTU of 1500, minus 60 for the max IP, minus 8 for UDP, gives
+ * 1432 bytes or so.  And that should be adjusted downward further for other
+ * encapsulations like PPPoE, so 1400 at most.
+ */
+#define DEFAULT_MTU                     1400
+#define DEFAULT_PT                      96
+#define DEFAULT_SSRC                    -1
+#define DEFAULT_TIMESTAMP_OFFSET        -1
+#define DEFAULT_SEQNUM_OFFSET           -1
+#define DEFAULT_MAX_PTIME               -1
+#define DEFAULT_MIN_PTIME               0
+#define DEFAULT_PERFECT_RTPTIME         TRUE
+#define DEFAULT_PTIME_MULTIPLE          0
+
+enum
+{
+  PROP_0,
+  PROP_MTU,
+  PROP_PT,
+  PROP_SSRC,
+  PROP_TIMESTAMP_OFFSET,
+  PROP_SEQNUM_OFFSET,
+  PROP_MAX_PTIME,
+  PROP_MIN_PTIME,
+  PROP_TIMESTAMP,
+  PROP_SEQNUM,
+  PROP_PERFECT_RTPTIME,
+  PROP_PTIME_MULTIPLE,
+  PROP_LAST
+};
+
+static void gst_basertppayload_class_init (GstBaseRTPPayloadClass * klass);
+static void gst_basertppayload_base_init (GstBaseRTPPayloadClass * klass);
+static void gst_basertppayload_init (GstBaseRTPPayload * basertppayload,
+    gpointer g_class);
+static void gst_basertppayload_finalize (GObject * object);
+
+static gboolean gst_basertppayload_sink_setcaps (GstPad * pad, GstCaps * caps);
+static GstCaps *gst_basertppayload_sink_getcaps (GstPad * pad);
+static gboolean gst_basertppayload_event (GstPad * pad, GstEvent * event);
+static GstFlowReturn gst_basertppayload_chain (GstPad * pad,
+    GstBuffer * buffer);
+
+static void gst_basertppayload_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_basertppayload_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+
+static GstStateChangeReturn gst_basertppayload_change_state (GstElement *
+    element, GstStateChange transition);
+
+static GstElementClass *parent_class = NULL;
+
+/* FIXME 0.11: API should be changed to gst_base_typ_payload_xyz */
+
+GType
+gst_basertppayload_get_type (void)
+{
+  static GType basertppayload_type = 0;
+
+  if (!basertppayload_type) {
+    static const GTypeInfo basertppayload_info = {
+      sizeof (GstBaseRTPPayloadClass),
+      (GBaseInitFunc) gst_basertppayload_base_init,
+      NULL,
+      (GClassInitFunc) gst_basertppayload_class_init,
+      NULL,
+      NULL,
+      sizeof (GstBaseRTPPayload),
+      0,
+      (GInstanceInitFunc) gst_basertppayload_init,
+    };
+
+    basertppayload_type =
+        g_type_register_static (GST_TYPE_ELEMENT, "GstBaseRTPPayload",
+        &basertppayload_info, G_TYPE_FLAG_ABSTRACT);
+  }
+  return basertppayload_type;
+}
+
+static void
+gst_basertppayload_base_init (GstBaseRTPPayloadClass * klass)
+{
+}
+
+static void
+gst_basertppayload_class_init (GstBaseRTPPayloadClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  g_type_class_add_private (klass, sizeof (GstBaseRTPPayloadPrivate));
+
+  parent_class = g_type_class_peek_parent (klass);
+
+  gobject_class->finalize = gst_basertppayload_finalize;
+
+  gobject_class->set_property = gst_basertppayload_set_property;
+  gobject_class->get_property = gst_basertppayload_get_property;
+
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_MTU,
+      g_param_spec_uint ("mtu", "MTU",
+          "Maximum size of one packet",
+          28, G_MAXUINT, DEFAULT_MTU,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_PT,
+      g_param_spec_uint ("pt", "payload type",
+          "The payload type of the packets", 0, 0x80, DEFAULT_PT,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_SSRC,
+      g_param_spec_uint ("ssrc", "SSRC",
+          "The SSRC of the packets (default == random)", 0, G_MAXUINT32,
+          DEFAULT_SSRC, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (G_OBJECT_CLASS (klass),
+      PROP_TIMESTAMP_OFFSET, g_param_spec_uint ("timestamp-offset",
+          "Timestamp Offset",
+          "Offset to add to all outgoing timestamps (default = random)", 0,
+          G_MAXUINT32, DEFAULT_TIMESTAMP_OFFSET,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_SEQNUM_OFFSET,
+      g_param_spec_int ("seqnum-offset", "Sequence number Offset",
+          "Offset to add to all outgoing seqnum (-1 = random)", -1, G_MAXUINT16,
+          DEFAULT_SEQNUM_OFFSET, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_MAX_PTIME,
+      g_param_spec_int64 ("max-ptime", "Max packet time",
+          "Maximum duration of the packet data in ns (-1 = unlimited up to MTU)",
+          -1, G_MAXINT64, DEFAULT_MAX_PTIME,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  /**
+   * GstBaseRTPAudioPayload:min-ptime:
+   *
+   * Minimum duration of the packet data in ns (can't go above MTU)
+   *
+   * Since: 0.10.13
+   **/
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_MIN_PTIME,
+      g_param_spec_int64 ("min-ptime", "Min packet time",
+          "Minimum duration of the packet data in ns (can't go above MTU)",
+          0, G_MAXINT64, DEFAULT_MIN_PTIME,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TIMESTAMP,
+      g_param_spec_uint ("timestamp", "Timestamp",
+          "The RTP timestamp of the last processed packet",
+          0, G_MAXUINT32, 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_SEQNUM,
+      g_param_spec_uint ("seqnum", "Sequence number",
+          "The RTP sequence number of the last processed packet",
+          0, G_MAXUINT16, 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+
+  /**
+   * GstBaseRTPAudioPayload:perfect-rtptime:
+   *
+   * Try to use the offset fields to generate perfect RTP timestamps. when this
+   * option is disabled, RTP timestamps are generated from the GStreamer
+   * timestamps, which could result in RTP timestamps that don't increment with
+   * the amount of data in the packet.
+   *
+   * Since: 0.10.25
+   */
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_PERFECT_RTPTIME,
+      g_param_spec_boolean ("perfect-rtptime", "Perfect RTP Time",
+          "Generate perfect RTP timestamps when possible",
+          DEFAULT_PERFECT_RTPTIME, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  /**
+   * GstBaseRTPAudioPayload:ptime-multiple:
+   *
+   * Force buffers to be multiples of this duration in ns (0 disables)
+   *
+   * Since: 0.10.29
+   **/
+  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_PTIME_MULTIPLE,
+      g_param_spec_int64 ("ptime-multiple", "Packet time multiple",
+          "Force buffers to be multiples of this duration in ns (0 disables)",
+          0, G_MAXINT64, DEFAULT_PTIME_MULTIPLE,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  gstelement_class->change_state = gst_basertppayload_change_state;
+
+  GST_DEBUG_CATEGORY_INIT (basertppayload_debug, "basertppayload", 0,
+      "Base class for RTP Payloaders");
+}
+
+static void
+gst_basertppayload_init (GstBaseRTPPayload * basertppayload, gpointer g_class)
+{
+  GstPadTemplate *templ;
+  GstBaseRTPPayloadPrivate *priv;
+
+  basertppayload->priv = priv =
+      GST_BASE_RTP_PAYLOAD_GET_PRIVATE (basertppayload);
+
+  templ =
+      gst_element_class_get_pad_template (GST_ELEMENT_CLASS (g_class), "src");
+  g_return_if_fail (templ != NULL);
+
+  basertppayload->srcpad = gst_pad_new_from_template (templ, "src");
+  gst_element_add_pad (GST_ELEMENT (basertppayload), basertppayload->srcpad);
+
+  templ =
+      gst_element_class_get_pad_template (GST_ELEMENT_CLASS (g_class), "sink");
+  g_return_if_fail (templ != NULL);
+
+  basertppayload->sinkpad = gst_pad_new_from_template (templ, "sink");
+  gst_pad_set_setcaps_function (basertppayload->sinkpad,
+      gst_basertppayload_sink_setcaps);
+  gst_pad_set_getcaps_function (basertppayload->sinkpad,
+      gst_basertppayload_sink_getcaps);
+  gst_pad_set_event_function (basertppayload->sinkpad,
+      gst_basertppayload_event);
+  gst_pad_set_chain_function (basertppayload->sinkpad,
+      gst_basertppayload_chain);
+  gst_element_add_pad (GST_ELEMENT (basertppayload), basertppayload->sinkpad);
+
+  basertppayload->seq_rand = g_rand_new_with_seed (g_random_int ());
+  basertppayload->ssrc_rand = g_rand_new_with_seed (g_random_int ());
+  basertppayload->ts_rand = g_rand_new_with_seed (g_random_int ());
+
+  basertppayload->mtu = DEFAULT_MTU;
+  basertppayload->pt = DEFAULT_PT;
+  basertppayload->seqnum_offset = DEFAULT_SEQNUM_OFFSET;
+  basertppayload->ssrc = DEFAULT_SSRC;
+  basertppayload->ts_offset = DEFAULT_TIMESTAMP_OFFSET;
+  priv->seqnum_offset_random = (basertppayload->seqnum_offset == -1);
+  priv->ts_offset_random = (basertppayload->ts_offset == -1);
+  priv->ssrc_random = (basertppayload->ssrc == -1);
+
+  basertppayload->max_ptime = DEFAULT_MAX_PTIME;
+  basertppayload->min_ptime = DEFAULT_MIN_PTIME;
+  basertppayload->priv->perfect_rtptime = DEFAULT_PERFECT_RTPTIME;
+  basertppayload->abidata.ABI.ptime_multiple = DEFAULT_PTIME_MULTIPLE;
+
+  basertppayload->media = NULL;
+  basertppayload->encoding_name = NULL;
+
+  basertppayload->clock_rate = 0;
+
+  basertppayload->priv->caps_max_ptime = DEFAULT_MAX_PTIME;
+  basertppayload->priv->prop_max_ptime = DEFAULT_MAX_PTIME;
+}
+
+static void
+gst_basertppayload_finalize (GObject * object)
+{
+  GstBaseRTPPayload *basertppayload;
+
+  basertppayload = GST_BASE_RTP_PAYLOAD (object);
+
+  g_rand_free (basertppayload->seq_rand);
+  basertppayload->seq_rand = NULL;
+  g_rand_free (basertppayload->ssrc_rand);
+  basertppayload->ssrc_rand = NULL;
+  g_rand_free (basertppayload->ts_rand);
+  basertppayload->ts_rand = NULL;
+
+  g_free (basertppayload->media);
+  basertppayload->media = NULL;
+  g_free (basertppayload->encoding_name);
+  basertppayload->encoding_name = NULL;
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static gboolean
+gst_basertppayload_sink_setcaps (GstPad * pad, GstCaps * caps)
+{
+  GstBaseRTPPayload *basertppayload;
+  GstBaseRTPPayloadClass *basertppayload_class;
+  gboolean ret = TRUE;
+
+  GST_DEBUG_OBJECT (pad, "setting caps %" GST_PTR_FORMAT, caps);
+  basertppayload = GST_BASE_RTP_PAYLOAD (gst_pad_get_parent (pad));
+  basertppayload_class = GST_BASE_RTP_PAYLOAD_GET_CLASS (basertppayload);
+
+  if (basertppayload_class->set_caps)
+    ret = basertppayload_class->set_caps (basertppayload, caps);
+
+  gst_object_unref (basertppayload);
+
+  return ret;
+}
+
+static GstCaps *
+gst_basertppayload_sink_getcaps (GstPad * pad)
+{
+  GstBaseRTPPayload *basertppayload;
+  GstBaseRTPPayloadClass *basertppayload_class;
+  GstCaps *caps = NULL;
+
+  GST_DEBUG_OBJECT (pad, "getting caps");
+
+  basertppayload = GST_BASE_RTP_PAYLOAD (gst_pad_get_parent (pad));
+  basertppayload_class = GST_BASE_RTP_PAYLOAD_GET_CLASS (basertppayload);
+
+  if (basertppayload_class->get_caps)
+    caps = basertppayload_class->get_caps (basertppayload, pad);
+
+  if (!caps) {
+    caps = GST_PAD_TEMPLATE_CAPS (GST_PAD_PAD_TEMPLATE (pad));
+    GST_DEBUG_OBJECT (pad,
+        "using pad template %p with caps %p %" GST_PTR_FORMAT,
+        GST_PAD_PAD_TEMPLATE (pad), caps, caps);
+
+    caps = gst_caps_ref (caps);
+  }
+
+  gst_object_unref (basertppayload);
+
+  return caps;
+}
+
+static gboolean
+gst_basertppayload_event (GstPad * pad, GstEvent * event)
+{
+  GstBaseRTPPayload *basertppayload;
+  GstBaseRTPPayloadClass *basertppayload_class;
+  gboolean res;
+
+  basertppayload = GST_BASE_RTP_PAYLOAD (gst_pad_get_parent (pad));
+  if (G_UNLIKELY (basertppayload == NULL)) {
+    gst_event_unref (event);
+    return FALSE;
+  }
+  basertppayload_class = GST_BASE_RTP_PAYLOAD_GET_CLASS (basertppayload);
+
+  if (basertppayload_class->handle_event) {
+    res = basertppayload_class->handle_event (pad, event);
+    if (res)
+      goto done;
+  }
+
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_FLUSH_START:
+      res = gst_pad_event_default (pad, event);
+      break;
+    case GST_EVENT_FLUSH_STOP:
+      res = gst_pad_event_default (pad, event);
+      gst_segment_init (&basertppayload->segment, GST_FORMAT_UNDEFINED);
+      break;
+    case GST_EVENT_NEWSEGMENT:
+    {
+      gboolean update;
+      gdouble rate, arate;
+      GstFormat fmt;
+      gint64 start, stop, position;
+      GstSegment *segment;
+
+      segment = &basertppayload->segment;
+
+      gst_event_parse_new_segment_full (event, &update, &rate, &arate, &fmt,
+          &start, &stop, &position);
+      gst_segment_set_newsegment_full (segment, update, rate, arate, fmt, start,
+          stop, position);
+
+      GST_DEBUG_OBJECT (basertppayload,
+          "configured NEWSEGMENT update %d, rate %lf, applied rate %lf, "
+          "format %d, "
+          "%" G_GINT64_FORMAT " -- %" G_GINT64_FORMAT ", time %"
+          G_GINT64_FORMAT ", accum %" G_GINT64_FORMAT, update, rate, arate,
+          segment->format, segment->start, segment->stop, segment->time,
+          segment->accum);
+      /* fallthrough */
+    }
+    default:
+      res = gst_pad_event_default (pad, event);
+      break;
+  }
+
+done:
+  gst_object_unref (basertppayload);
+
+  return res;
+}
+
+
+static GstFlowReturn
+gst_basertppayload_chain (GstPad * pad, GstBuffer * buffer)
+{
+  GstBaseRTPPayload *basertppayload;
+  GstBaseRTPPayloadClass *basertppayload_class;
+  GstFlowReturn ret;
+
+  basertppayload = GST_BASE_RTP_PAYLOAD (gst_pad_get_parent (pad));
+  basertppayload_class = GST_BASE_RTP_PAYLOAD_GET_CLASS (basertppayload);
+
+  if (!basertppayload_class->handle_buffer)
+    goto no_function;
+
+  ret = basertppayload_class->handle_buffer (basertppayload, buffer);
+
+  gst_object_unref (basertppayload);
+
+  return ret;
+
+  /* ERRORS */
+no_function:
+  {
+    GST_ELEMENT_ERROR (basertppayload, STREAM, NOT_IMPLEMENTED, (NULL),
+        ("subclass did not implement handle_buffer function"));
+    gst_object_unref (basertppayload);
+    gst_buffer_unref (buffer);
+    return GST_FLOW_ERROR;
+  }
+}
+
+/**
+ * gst_basertppayload_set_options:
+ * @payload: a #GstBaseRTPPayload
+ * @media: the media type (typically "audio" or "video")
+ * @dynamic: if the payload type is dynamic
+ * @encoding_name: the encoding name
+ * @clock_rate: the clock rate of the media
+ *
+ * Set the rtp options of the payloader. These options will be set in the caps
+ * of the payloader. Subclasses must call this method before calling
+ * gst_basertppayload_push() or gst_basertppayload_set_outcaps().
+ */
+void
+gst_basertppayload_set_options (GstBaseRTPPayload * payload,
+    const gchar * media, gboolean dynamic, const gchar * encoding_name,
+    guint32 clock_rate)
+{
+  g_return_if_fail (payload != NULL);
+  g_return_if_fail (clock_rate != 0);
+
+  g_free (payload->media);
+  payload->media = g_strdup (media);
+  payload->dynamic = dynamic;
+  g_free (payload->encoding_name);
+  payload->encoding_name = g_strdup (encoding_name);
+  payload->clock_rate = clock_rate;
+}
+
+static gboolean
+copy_fixed (GQuark field_id, const GValue * value, GstStructure * dest)
+{
+  if (gst_value_is_fixed (value)) {
+    gst_structure_id_set_value (dest, field_id, value);
+  }
+  return TRUE;
+}
+
+static void
+update_max_ptime (GstBaseRTPPayload * basertppayload)
+{
+  if (basertppayload->priv->caps_max_ptime != -1 &&
+      basertppayload->priv->prop_max_ptime != -1)
+    basertppayload->max_ptime = MIN (basertppayload->priv->caps_max_ptime,
+        basertppayload->priv->prop_max_ptime);
+  else if (basertppayload->priv->caps_max_ptime != -1)
+    basertppayload->max_ptime = basertppayload->priv->caps_max_ptime;
+  else if (basertppayload->priv->prop_max_ptime != -1)
+    basertppayload->max_ptime = basertppayload->priv->prop_max_ptime;
+  else
+    basertppayload->max_ptime = DEFAULT_MAX_PTIME;
+}
+
+/**
+ * gst_basertppayload_set_outcaps:
+ * @payload: a #GstBaseRTPPayload
+ * @fieldname: the first field name or %NULL
+ * @...: field values
+ *
+ * Configure the output caps with the optional parameters.
+ *
+ * Variable arguments should be in the form field name, field type
+ * (as a GType), value(s).  The last variable argument should be NULL.
+ *
+ * Returns: %TRUE if the caps could be set.
+ */
+gboolean
+gst_basertppayload_set_outcaps (GstBaseRTPPayload * payload,
+    const gchar * fieldname, ...)
+{
+  GstCaps *srccaps, *peercaps;
+  gboolean res;
+
+  /* fill in the defaults, their properties cannot be negotiated. */
+  srccaps = gst_caps_new_simple ("application/x-rtp",
+      "media", G_TYPE_STRING, payload->media,
+      "clock-rate", G_TYPE_INT, payload->clock_rate,
+      "encoding-name", G_TYPE_STRING, payload->encoding_name, NULL);
+
+  GST_DEBUG_OBJECT (payload, "defaults: %" GST_PTR_FORMAT, srccaps);
+
+  if (fieldname) {
+    va_list varargs;
+
+    /* override with custom properties */
+    va_start (varargs, fieldname);
+    gst_caps_set_simple_valist (srccaps, fieldname, varargs);
+    va_end (varargs);
+
+    GST_DEBUG_OBJECT (payload, "custom added: %" GST_PTR_FORMAT, srccaps);
+  }
+
+  payload->priv->caps_max_ptime = DEFAULT_MAX_PTIME;
+  payload->abidata.ABI.ptime = 0;
+
+  /* the peer caps can override some of the defaults */
+  peercaps = gst_pad_peer_get_caps (payload->srcpad);
+  if (peercaps == NULL) {
+    /* no peer caps, just add the other properties */
+    gst_caps_set_simple (srccaps,
+        "payload", G_TYPE_INT, GST_BASE_RTP_PAYLOAD_PT (payload),
+        "ssrc", G_TYPE_UINT, payload->current_ssrc,
+        "clock-base", G_TYPE_UINT, payload->ts_base,
+        "seqnum-base", G_TYPE_UINT, payload->seqnum_base, NULL);
+
+    GST_DEBUG_OBJECT (payload, "no peer caps: %" GST_PTR_FORMAT, srccaps);
+  } else {
+    GstCaps *temp;
+    GstStructure *s, *d;
+    const GValue *value;
+    gint pt;
+    guint max_ptime, ptime;
+
+    /* peer provides caps we can use to fixate, intersect. This always returns a
+     * writable caps. */
+    temp = gst_caps_intersect (srccaps, peercaps);
+    gst_caps_unref (srccaps);
+    gst_caps_unref (peercaps);
+
+    if (gst_caps_is_empty (temp)) {
+      gst_caps_unref (temp);
+      return FALSE;
+    }
+
+    /* now fixate, start by taking the first caps */
+    gst_caps_truncate (temp);
+
+    /* get first structure */
+    s = gst_caps_get_structure (temp, 0);
+
+    if (gst_structure_get_uint (s, "maxptime", &max_ptime))
+      payload->priv->caps_max_ptime = max_ptime * GST_MSECOND;
+
+    if (gst_structure_get_uint (s, "ptime", &ptime))
+      payload->abidata.ABI.ptime = ptime * GST_MSECOND;
+
+    if (gst_structure_get_int (s, "payload", &pt)) {
+      /* use peer pt */
+      GST_BASE_RTP_PAYLOAD_PT (payload) = pt;
+      GST_LOG_OBJECT (payload, "using peer pt %d", pt);
+    } else {
+      if (gst_structure_has_field (s, "payload")) {
+        /* can only fixate if there is a field */
+        gst_structure_fixate_field_nearest_int (s, "payload",
+            GST_BASE_RTP_PAYLOAD_PT (payload));
+        gst_structure_get_int (s, "payload", &pt);
+        GST_LOG_OBJECT (payload, "using peer pt %d", pt);
+      } else {
+        /* no pt field, use the internal pt */
+        pt = GST_BASE_RTP_PAYLOAD_PT (payload);
+        gst_structure_set (s, "payload", G_TYPE_INT, pt, NULL);
+        GST_LOG_OBJECT (payload, "using internal pt %d", pt);
+      }
+    }
+
+    if (gst_structure_has_field_typed (s, "ssrc", G_TYPE_UINT)) {
+      value = gst_structure_get_value (s, "ssrc");
+      payload->current_ssrc = g_value_get_uint (value);
+      GST_LOG_OBJECT (payload, "using peer ssrc %08x", payload->current_ssrc);
+    } else {
+      /* FIXME, fixate_nearest_uint would be even better */
+      gst_structure_set (s, "ssrc", G_TYPE_UINT, payload->current_ssrc, NULL);
+      GST_LOG_OBJECT (payload, "using internal ssrc %08x",
+          payload->current_ssrc);
+    }
+
+    if (gst_structure_has_field_typed (s, "clock-base", G_TYPE_UINT)) {
+      value = gst_structure_get_value (s, "clock-base");
+      payload->ts_base = g_value_get_uint (value);
+      GST_LOG_OBJECT (payload, "using peer clock-base %u", payload->ts_base);
+    } else {
+      /* FIXME, fixate_nearest_uint would be even better */
+      gst_structure_set (s, "clock-base", G_TYPE_UINT, payload->ts_base, NULL);
+      GST_LOG_OBJECT (payload, "using internal clock-base %u",
+          payload->ts_base);
+    }
+    if (gst_structure_has_field_typed (s, "seqnum-base", G_TYPE_UINT)) {
+      value = gst_structure_get_value (s, "seqnum-base");
+      payload->seqnum_base = g_value_get_uint (value);
+      GST_LOG_OBJECT (payload, "using peer seqnum-base %u",
+          payload->seqnum_base);
+    } else {
+      /* FIXME, fixate_nearest_uint would be even better */
+      gst_structure_set (s, "seqnum-base", G_TYPE_UINT, payload->seqnum_base,
+          NULL);
+      GST_LOG_OBJECT (payload, "using internal seqnum-base %u",
+          payload->seqnum_base);
+    }
+
+    /* make the target caps by copying over all the fixed caps, removing the
+     * unfixed caps. */
+    srccaps = gst_caps_new_simple (gst_structure_get_name (s), NULL);
+    d = gst_caps_get_structure (srccaps, 0);
+
+    gst_structure_foreach (s, (GstStructureForeachFunc) copy_fixed, d);
+
+    gst_caps_unref (temp);
+
+    GST_DEBUG_OBJECT (payload, "with peer caps: %" GST_PTR_FORMAT, srccaps);
+  }
+
+  update_max_ptime (payload);
+
+  res = gst_pad_set_caps (GST_BASE_RTP_PAYLOAD_SRCPAD (payload), srccaps);
+  gst_caps_unref (srccaps);
+
+  return res;
+}
+
+/**
+ * gst_basertppayload_is_filled:
+ * @payload: a #GstBaseRTPPayload
+ * @size: the size of the packet
+ * @duration: the duration of the packet
+ *
+ * Check if the packet with @size and @duration would exceed the configured
+ * maximum size.
+ *
+ * Returns: %TRUE if the packet of @size and @duration would exceed the
+ * configured MTU or max_ptime.
+ */
+gboolean
+gst_basertppayload_is_filled (GstBaseRTPPayload * payload,
+    guint size, GstClockTime duration)
+{
+  if (size > payload->mtu)
+    return TRUE;
+
+  if (payload->max_ptime != -1 && duration >= payload->max_ptime)
+    return TRUE;
+
+  return FALSE;
+}
+
+typedef struct
+{
+  GstBaseRTPPayload *payload;
+  guint32 ssrc;
+  guint16 seqnum;
+  guint8 pt;
+  GstCaps *caps;
+  GstClockTime timestamp;
+  guint64 offset;
+  guint32 rtptime;
+} HeaderData;
+
+static GstBufferListItem
+find_timestamp (GstBuffer ** buffer, guint group, guint idx, HeaderData * data)
+{
+  data->timestamp = GST_BUFFER_TIMESTAMP (*buffer);
+  data->offset = GST_BUFFER_OFFSET (*buffer);
+
+  /* stop when we find a timestamp. We take whatever offset is associated with
+   * the timestamp (if any) to do perfect timestamps when we need to. */
+  if (data->timestamp != -1)
+    return GST_BUFFER_LIST_END;
+  else
+    return GST_BUFFER_LIST_CONTINUE;
+}
+
+static GstBufferListItem
+set_headers (GstBuffer ** buffer, guint group, guint idx, HeaderData * data)
+{
+  gst_rtp_buffer_set_ssrc (*buffer, data->ssrc);
+  gst_rtp_buffer_set_payload_type (*buffer, data->pt);
+  gst_rtp_buffer_set_seq (*buffer, data->seqnum);
+  gst_rtp_buffer_set_timestamp (*buffer, data->rtptime);
+  gst_buffer_set_caps (*buffer, data->caps);
+  /* increment the seqnum for each buffer */
+  data->seqnum++;
+
+  return GST_BUFFER_LIST_SKIP_GROUP;
+}
+
+/* Updates the SSRC, payload type, seqnum and timestamp of the RTP buffer
+ * before the buffer is pushed. */
+static GstFlowReturn
+gst_basertppayload_prepare_push (GstBaseRTPPayload * payload,
+    gpointer obj, gboolean is_list)
+{
+  GstBaseRTPPayloadPrivate *priv;
+  HeaderData data;
+
+  if (payload->clock_rate == 0)
+    goto no_rate;
+
+  priv = payload->priv;
+
+  /* update first, so that the property is set to the last
+   * seqnum pushed */
+  payload->seqnum = priv->next_seqnum;
+
+  /* fill in the fields we want to set on all headers */
+  data.payload = payload;
+  data.seqnum = payload->seqnum;
+  data.ssrc = payload->current_ssrc;
+  data.pt = payload->pt;
+  data.caps = GST_PAD_CAPS (payload->srcpad);
+
+  /* find the first buffer with a timestamp */
+  if (is_list) {
+    data.timestamp = -1;
+    data.offset = GST_BUFFER_OFFSET_NONE;
+    gst_buffer_list_foreach (GST_BUFFER_LIST_CAST (obj),
+        (GstBufferListFunc) find_timestamp, &data);
+  } else {
+    data.timestamp = GST_BUFFER_TIMESTAMP (GST_BUFFER_CAST (obj));
+    data.offset = GST_BUFFER_OFFSET (GST_BUFFER_CAST (obj));
+  }
+
+  /* convert to RTP time */
+  if (priv->perfect_rtptime && data.offset != GST_BUFFER_OFFSET_NONE) {
+    /* if we have an offset, use that for making an RTP timestamp */
+    data.rtptime = payload->ts_base + data.offset;
+    GST_LOG_OBJECT (payload,
+        "Using offset %" G_GUINT64_FORMAT " for RTP timestamp", data.offset);
+  } else if (GST_CLOCK_TIME_IS_VALID (data.timestamp)) {
+    gint64 rtime;
+
+    /* no offset, use the gstreamer timestamp */
+    rtime = gst_segment_to_running_time (&payload->segment, GST_FORMAT_TIME,
+        data.timestamp);
+
+    if (rtime == -1) {
+      GST_LOG_OBJECT (payload, "Clipped timestamp, using base RTP timestamp");
+      rtime = 0;
+    } else {
+      GST_LOG_OBJECT (payload,
+          "Using running_time %" GST_TIME_FORMAT " for RTP timestamp",
+          GST_TIME_ARGS (rtime));
+      rtime =
+          gst_util_uint64_scale_int (rtime, payload->clock_rate, GST_SECOND);
+    }
+    /* add running_time in clock-rate units to the base timestamp */
+    data.rtptime = payload->ts_base + rtime;
+  } else {
+    GST_LOG_OBJECT (payload,
+        "Using previous RTP timestamp %" G_GUINT32_FORMAT, payload->timestamp);
+    /* no timestamp to convert, take previous timestamp */
+    data.rtptime = payload->timestamp;
+  }
+
+  /* set ssrc, payload type, seq number, caps and rtptime */
+  if (is_list) {
+    gst_buffer_list_foreach (GST_BUFFER_LIST_CAST (obj),
+        (GstBufferListFunc) set_headers, &data);
+  } else {
+    GstBuffer *buf = GST_BUFFER_CAST (obj);
+    set_headers (&buf, 0, 0, &data);
+  }
+
+  priv->next_seqnum = data.seqnum;
+  payload->timestamp = data.rtptime;
+
+  GST_LOG_OBJECT (payload,
+      "Preparing to push packet with size %d, seq=%d, rtptime=%u, timestamp %"
+      GST_TIME_FORMAT, (is_list) ? -1 :
+      GST_BUFFER_SIZE (GST_BUFFER (obj)), payload->seqnum, data.rtptime,
+      GST_TIME_ARGS (data.timestamp));
+
+  if (g_atomic_int_compare_and_exchange (&payload->
+          priv->notified_first_timestamp, 1, 0)) {
+    g_object_notify (G_OBJECT (payload), "timestamp");
+    g_object_notify (G_OBJECT (payload), "seqnum");
+  }
+
+  return GST_FLOW_OK;
+
+  /* ERRORS */
+no_rate:
+  {
+    GST_ELEMENT_ERROR (payload, STREAM, NOT_IMPLEMENTED, (NULL),
+        ("subclass did not specify clock-rate"));
+    return GST_FLOW_ERROR;
+  }
+}
+
+/**
+ * gst_basertppayload_push_list:
+ * @payload: a #GstBaseRTPPayload
+ * @list: a #GstBufferList
+ *
+ * Push @list to the peer element of the payloader. The SSRC, payload type,
+ * seqnum and timestamp of the RTP buffer will be updated first.
+ *
+ * This function takes ownership of @list.
+ *
+ * Returns: a #GstFlowReturn.
+ *
+ * Since: 0.10.24
+ */
+GstFlowReturn
+gst_basertppayload_push_list (GstBaseRTPPayload * payload, GstBufferList * list)
+{
+  GstFlowReturn res;
+
+  res = gst_basertppayload_prepare_push (payload, list, TRUE);
+
+  if (G_LIKELY (res == GST_FLOW_OK))
+    res = gst_pad_push_list (payload->srcpad, list);
+  else
+    gst_buffer_list_unref (list);
+
+  return res;
+}
+
+/**
+ * gst_basertppayload_push:
+ * @payload: a #GstBaseRTPPayload
+ * @buffer: a #GstBuffer
+ *
+ * Push @buffer to the peer element of the payloader. The SSRC, payload type,
+ * seqnum and timestamp of the RTP buffer will be updated first.
+ *
+ * This function takes ownership of @buffer.
+ *
+ * Returns: a #GstFlowReturn.
+ */
+GstFlowReturn
+gst_basertppayload_push (GstBaseRTPPayload * payload, GstBuffer * buffer)
+{
+  GstFlowReturn res;
+
+  res = gst_basertppayload_prepare_push (payload, buffer, FALSE);
+
+  if (G_LIKELY (res == GST_FLOW_OK))
+    res = gst_pad_push (payload->srcpad, buffer);
+  else
+    gst_buffer_unref (buffer);
+
+  return res;
+}
+
+static void
+gst_basertppayload_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstBaseRTPPayload *basertppayload;
+  GstBaseRTPPayloadPrivate *priv;
+  gint64 val;
+
+  basertppayload = GST_BASE_RTP_PAYLOAD (object);
+  priv = basertppayload->priv;
+
+  switch (prop_id) {
+    case PROP_MTU:
+      basertppayload->mtu = g_value_get_uint (value);
+      break;
+    case PROP_PT:
+      basertppayload->pt = g_value_get_uint (value);
+      break;
+    case PROP_SSRC:
+      val = g_value_get_uint (value);
+      basertppayload->ssrc = val;
+      priv->ssrc_random = FALSE;
+      break;
+    case PROP_TIMESTAMP_OFFSET:
+      val = g_value_get_uint (value);
+      basertppayload->ts_offset = val;
+      priv->ts_offset_random = FALSE;
+      break;
+    case PROP_SEQNUM_OFFSET:
+      val = g_value_get_int (value);
+      basertppayload->seqnum_offset = val;
+      priv->seqnum_offset_random = (val == -1);
+      GST_DEBUG_OBJECT (basertppayload, "seqnum offset 0x%04x, random %d",
+          basertppayload->seqnum_offset, priv->seqnum_offset_random);
+      break;
+    case PROP_MAX_PTIME:
+      basertppayload->priv->prop_max_ptime = g_value_get_int64 (value);
+      update_max_ptime (basertppayload);
+      break;
+    case PROP_MIN_PTIME:
+      basertppayload->min_ptime = g_value_get_int64 (value);
+      break;
+    case PROP_PERFECT_RTPTIME:
+      priv->perfect_rtptime = g_value_get_boolean (value);
+      break;
+    case PROP_PTIME_MULTIPLE:
+      basertppayload->abidata.ABI.ptime_multiple = g_value_get_int64 (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_basertppayload_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstBaseRTPPayload *basertppayload;
+  GstBaseRTPPayloadPrivate *priv;
+
+  basertppayload = GST_BASE_RTP_PAYLOAD (object);
+  priv = basertppayload->priv;
+
+  switch (prop_id) {
+    case PROP_MTU:
+      g_value_set_uint (value, basertppayload->mtu);
+      break;
+    case PROP_PT:
+      g_value_set_uint (value, basertppayload->pt);
+      break;
+    case PROP_SSRC:
+      if (priv->ssrc_random)
+        g_value_set_uint (value, -1);
+      else
+        g_value_set_uint (value, basertppayload->ssrc);
+      break;
+    case PROP_TIMESTAMP_OFFSET:
+      if (priv->ts_offset_random)
+        g_value_set_uint (value, -1);
+      else
+        g_value_set_uint (value, (guint32) basertppayload->ts_offset);
+      break;
+    case PROP_SEQNUM_OFFSET:
+      if (priv->seqnum_offset_random)
+        g_value_set_int (value, -1);
+      else
+        g_value_set_int (value, (guint16) basertppayload->seqnum_offset);
+      break;
+    case PROP_MAX_PTIME:
+      g_value_set_int64 (value, basertppayload->max_ptime);
+      break;
+    case PROP_MIN_PTIME:
+      g_value_set_int64 (value, basertppayload->min_ptime);
+      break;
+    case PROP_TIMESTAMP:
+      g_value_set_uint (value, basertppayload->timestamp);
+      break;
+    case PROP_SEQNUM:
+      g_value_set_uint (value, basertppayload->seqnum);
+      break;
+    case PROP_PERFECT_RTPTIME:
+      g_value_set_boolean (value, priv->perfect_rtptime);
+      break;
+    case PROP_PTIME_MULTIPLE:
+      g_value_set_int64 (value, basertppayload->abidata.ABI.ptime_multiple);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static GstStateChangeReturn
+gst_basertppayload_change_state (GstElement * element,
+    GstStateChange transition)
+{
+  GstBaseRTPPayload *basertppayload;
+  GstBaseRTPPayloadPrivate *priv;
+  GstStateChangeReturn ret;
+
+  basertppayload = GST_BASE_RTP_PAYLOAD (element);
+  priv = basertppayload->priv;
+
+  switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+      break;
+    case GST_STATE_CHANGE_READY_TO_PAUSED:
+      gst_segment_init (&basertppayload->segment, GST_FORMAT_UNDEFINED);
+
+      if (priv->seqnum_offset_random)
+        basertppayload->seqnum_base = g_random_int_range (0, G_MAXUINT16);
+      else
+        basertppayload->seqnum_base = basertppayload->seqnum_offset;
+      priv->next_seqnum = basertppayload->seqnum_base;
+      basertppayload->seqnum = basertppayload->seqnum_base;
+
+      if (priv->ssrc_random)
+        basertppayload->current_ssrc = g_random_int ();
+      else
+        basertppayload->current_ssrc = basertppayload->ssrc;
+
+      if (priv->ts_offset_random)
+        basertppayload->ts_base = g_random_int ();
+      else
+        basertppayload->ts_base = basertppayload->ts_offset;
+      basertppayload->timestamp = basertppayload->ts_base;
+      g_atomic_int_set (&basertppayload->priv->notified_first_timestamp, 1);
+      break;
+    default:
+      break;
+  }
+
+  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
+      g_atomic_int_set (&basertppayload->priv->notified_first_timestamp, 1);
+      break;
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      break;
+    default:
+      break;
+  }
+  return ret;
+}