/* GStreamer plugin for forward error correction * Copyright (C) 2017 Pexip * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Author: Mikhail Fludkov */ /** * SECTION:element-rtpstorage * @short_description: RTP storage for forward error correction (FEC) in rtpbin * @title: rtpstorage * * Helper element for storing packets to aid later packet recovery from packet * loss using RED/FEC (Forward Error Correction). * * The purpose of this element is to store a moving window of packets which * downstream elements such as #GstRtpUlpFecDec can request in order to perform * recovery of lost packets upon receiving custom GstRtpPacketLost events, * usually from #GstRtpJitterBuffer. * * As such, when building a pipeline manually, it should have the form: * * ``` * rtpstorage ! rtpjitterbuffer ! rtpulpfecdec * ``` * * where rtpulpfecdec get passed a reference to the object pointed to by * the #GstRtpStorage:internal-storage property. * * The #GstRtpStorage:size-time property should be configured with a value * equal to the #GstRtpJitterBuffer latency, plus some tolerance, in the order * of milliseconds, for example in the example found at * , * `size-time` is configured as 200 + 50 milliseconds (latency + tolerance). * * When using #GstRtpBin, a storage element is created automatically, and * can be configured upon receiving the #GstRtpBin::new-storage signal. * * See also: #GstRtpBin, #GstRtpUlpFecDec * Since: 1.14 */ #include "gstrtpstorage.h" static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("application/x-rtp") ); static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS ("application/x-rtp") ); enum { PROP_0, PROP_SIZE_TIME, PROP_INTERNAL_STORAGE, N_PROPERTIES }; static GParamSpec *klass_properties[N_PROPERTIES] = { NULL, }; #define DEFAULT_SIZE_TIME (0) GST_DEBUG_CATEGORY (gst_rtp_storage_debug); #define GST_CAT_DEFAULT (gst_rtp_storage_debug) G_DEFINE_TYPE (GstRtpStorage, gst_rtp_storage, GST_TYPE_ELEMENT); static GstFlowReturn gst_rtp_storage_chain (GstPad * pad, GstObject * parent, GstBuffer * buf) { GstRtpStorage *self = GST_RTP_STORAGE (parent);; if (rtp_storage_append_buffer (self->storage, buf)) return gst_pad_push (self->srcpad, buf); return GST_FLOW_OK; } static void gst_rtp_storage_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstRtpStorage *self = GST_RTP_STORAGE (object); switch (prop_id) { case PROP_SIZE_TIME: GST_DEBUG_OBJECT (self, "RTP storage size set to %" GST_TIME_FORMAT, GST_TIME_ARGS (g_value_get_uint64 (value))); rtp_storage_set_size (self->storage, g_value_get_uint64 (value)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_rtp_storage_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstRtpStorage *self = GST_RTP_STORAGE (object); switch (prop_id) { case PROP_SIZE_TIME: g_value_set_uint64 (value, rtp_storage_get_size (self->storage)); break; case PROP_INTERNAL_STORAGE: { g_value_set_object (value, self->storage); break; } default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_rtp_storage_init (GstRtpStorage * self) { self->srcpad = gst_pad_new_from_static_template (&srctemplate, "src"); self->sinkpad = gst_pad_new_from_static_template (&sinktemplate, "sink"); GST_PAD_SET_PROXY_CAPS (self->sinkpad); GST_PAD_SET_PROXY_ALLOCATION (self->sinkpad); gst_pad_set_chain_function (self->sinkpad, gst_rtp_storage_chain); gst_element_add_pad (GST_ELEMENT (self), self->srcpad); gst_element_add_pad (GST_ELEMENT (self), self->sinkpad); self->storage = rtp_storage_new (); } static void gst_rtp_storage_dispose (GObject * obj) { GstRtpStorage *self = GST_RTP_STORAGE (obj); g_object_unref (self->storage); G_OBJECT_CLASS (gst_rtp_storage_parent_class)->dispose (obj); } static void gst_rtp_storage_class_init (GstRtpStorageClass * klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); GstElementClass *element_class = GST_ELEMENT_CLASS (klass); GST_DEBUG_CATEGORY_INIT (gst_rtp_storage_debug, "rtpstorage", 0, "RTP Storage"); GST_DEBUG_REGISTER_FUNCPTR (gst_rtp_storage_chain); gst_element_class_add_pad_template (element_class, gst_static_pad_template_get (&srctemplate)); gst_element_class_add_pad_template (element_class, gst_static_pad_template_get (&sinktemplate)); gst_element_class_set_static_metadata (element_class, "RTP storage", "Analyzer/RTP", "Helper element for various purposes " "(ex. recovering from packet loss using RED/FEC). " "Saves given number of RTP packets. " "Should be instantiated before jitterbuffer", "Mikhail Fludkov "); gobject_class->set_property = gst_rtp_storage_set_property; gobject_class->get_property = gst_rtp_storage_get_property; gobject_class->dispose = gst_rtp_storage_dispose; klass_properties[PROP_SIZE_TIME] = g_param_spec_uint64 ("size-time", "Storage size (in ns)", "The amount of data to keep in the storage (in ns, 0-disable)", 0, G_MAXUINT64, DEFAULT_SIZE_TIME, G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS); klass_properties[PROP_INTERNAL_STORAGE] = g_param_spec_object ("internal-storage", "Internal storage", "Internal RtpStorage object", G_TYPE_OBJECT, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS); g_object_class_install_properties (gobject_class, N_PROPERTIES, klass_properties); }