gstreamer/gst/rtp/gstrtpulpfecdec.c

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/* 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 <misha@pexip.com>
*/
/**
* SECTION:element-rtpulpfecdec
* @short_description: Generic RTP Forward Error Correction (FEC) decoder
* @title: rtpulpfecdec
*
* Generic Forward Error Correction (FEC) decoder for Uneven Level
* Protection (ULP) as described in RFC 5109.
*
* This element will work in combination with an upstream #GstRtpStorage
* element and attempt to recover packets declared lost through custom
* 'GstRTPPacketLost' events, usually emitted by #GstRtpJitterBuffer.
*
* As such, this element cannot be usefully used from the command line,
* because a reference to the upstream storage object needs to be
* provided to it through its #GstRtpUlpFecDec:storage property, example
* programs are available at
* <https://github.com/sdroege/gstreamer-rs/blob/master/examples/src/bin/rtpfecserver.rs>
* and
* <https://github.com/sdroege/gstreamer-rs/blob/master/examples/src/bin/rtpfecclient.rs>.
*
* Additionally, the payload types of the protection packets *must* be
* provided to this element via its #GstRtpUlpFecDec:pt property.
*
* When using #GstRtpBin, this element should be inserted through the
* #GstRtpBin::request-fec-decoder signal.
*
* See also: #GstRtpUlpFecEnc, #GstRtpBin, #GstRtpStorage
* Since: 1.14
*/
#include <gst/rtp/gstrtpbuffer.h>
#include <gst/rtp/gstrtp-enumtypes.h>
#include "rtpulpfeccommon.h"
#include "gstrtpulpfecdec.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_PT,
PROP_STORAGE,
PROP_RECOVERED,
PROP_UNRECOVERED,
N_PROPERTIES
};
#define DEFAULT_FEC_PT 0
static GParamSpec *klass_properties[N_PROPERTIES] = { NULL, };
GST_DEBUG_CATEGORY (gst_rtp_ulpfec_dec_debug);
#define GST_CAT_DEFAULT (gst_rtp_ulpfec_dec_debug)
G_DEFINE_TYPE (GstRtpUlpFecDec, gst_rtp_ulpfec_dec, GST_TYPE_ELEMENT);
#define RTP_FEC_MAP_INFO_NTH(dec, data) (&g_array_index (\
((GstRtpUlpFecDec *)dec)->info_arr, \
RtpUlpFecMapInfo, \
GPOINTER_TO_UINT(data)))
static gint
_compare_fec_map_info (gconstpointer a, gconstpointer b, gpointer userdata)
{
guint16 aseq =
gst_rtp_buffer_get_seq (&RTP_FEC_MAP_INFO_NTH (userdata, a)->rtp);
guint16 bseq =
gst_rtp_buffer_get_seq (&RTP_FEC_MAP_INFO_NTH (userdata, b)->rtp);
return gst_rtp_buffer_compare_seqnum (bseq, aseq);
}
static void
gst_rtp_ulpfec_dec_start (GstRtpUlpFecDec * self, GstBufferList * buflist,
guint8 fec_pt, guint16 lost_seq)
{
guint fec_packets = 0;
gsize i;
g_assert (NULL == self->info_media);
g_assert (0 == self->info_fec->len);
g_assert (0 == self->info_arr->len);
g_array_set_size (self->info_arr, gst_buffer_list_length (buflist));
for (i = 0;
i < gst_buffer_list_length (buflist) && !self->lost_packet_from_storage;
++i) {
GstBuffer *buffer = gst_buffer_list_get (buflist, i);
RtpUlpFecMapInfo *info = RTP_FEC_MAP_INFO_NTH (self, i);
if (!rtp_ulpfec_map_info_map (gst_buffer_ref (buffer), info))
g_assert_not_reached ();
if (fec_pt == gst_rtp_buffer_get_payload_type (&info->rtp)) {
GST_DEBUG_RTP_PACKET (self, "rtp header (fec)", &info->rtp);
++fec_packets;
if (rtp_ulpfec_buffer_is_valid (&info->rtp)) {
GST_DEBUG_FEC_PACKET (self, &info->rtp);
g_ptr_array_add (self->info_fec, GUINT_TO_POINTER (i));
}
} else {
GST_LOG_RTP_PACKET (self, "rtp header (incoming)", &info->rtp);
if (lost_seq == gst_rtp_buffer_get_seq (&info->rtp)) {
GST_DEBUG_OBJECT (self, "Received lost packet from from the storage");
g_list_free (self->info_media);
self->info_media = NULL;
self->lost_packet_from_storage = TRUE;
}
self->info_media =
g_list_insert_sorted_with_data (self->info_media,
GUINT_TO_POINTER (i), _compare_fec_map_info, self);
}
}
if (!self->lost_packet_from_storage) {
self->fec_packets_received += fec_packets;
self->fec_packets_rejected += fec_packets - self->info_fec->len;
}
}
static void
gst_rtp_ulpfec_dec_stop (GstRtpUlpFecDec * self)
{
g_array_set_size (self->info_arr, 0);
g_ptr_array_set_size (self->info_fec, 0);
g_list_free (self->info_media);
self->info_media = NULL;
self->lost_packet_from_storage = FALSE;
self->lost_packet_returned = FALSE;
}
static guint64
gst_rtp_ulpfec_dec_get_media_buffers_mask (GstRtpUlpFecDec * self,
guint16 fec_seq_base)
{
guint64 mask = 0;
GList *it;
for (it = self->info_media; it; it = it->next) {
RtpUlpFecMapInfo *info = RTP_FEC_MAP_INFO_NTH (self, it->data);
mask |=
rtp_ulpfec_packet_mask_from_seqnum (gst_rtp_buffer_get_seq (&info->rtp),
fec_seq_base, TRUE);
}
return mask;
}
static gboolean
gst_rtp_ulpfec_dec_is_recovered_pt_valid (GstRtpUlpFecDec * self, gint media_pt,
guint8 recovered_pt)
{
GList *it;
if (media_pt == recovered_pt)
return TRUE;
for (it = self->info_media; it; it = it->next) {
RtpUlpFecMapInfo *info = RTP_FEC_MAP_INFO_NTH (self, it->data);
if (gst_rtp_buffer_get_payload_type (&info->rtp) == recovered_pt)
return TRUE;
}
return FALSE;
}
static GstBuffer *
gst_rtp_ulpfec_dec_recover_from_fec (GstRtpUlpFecDec * self,
RtpUlpFecMapInfo * info_fec, guint32 ssrc, gint media_pt, guint16 seq,
guint8 * dst_pt)
{
guint64 fec_mask = rtp_ulpfec_buffer_get_mask (&info_fec->rtp);
gboolean fec_mask_long = rtp_ulpfec_buffer_get_fechdr (&info_fec->rtp)->L;
guint16 fec_seq_base = rtp_ulpfec_buffer_get_seq_base (&info_fec->rtp);
GstBuffer *ret;
GList *it;
g_array_set_size (self->scratch_buf, 0);
rtp_buffer_to_ulpfec_bitstring (&info_fec->rtp, self->scratch_buf, TRUE,
fec_mask_long);
for (it = self->info_media; it; it = it->next) {
RtpUlpFecMapInfo *info = RTP_FEC_MAP_INFO_NTH (self, it->data);
guint64 packet_mask =
rtp_ulpfec_packet_mask_from_seqnum (gst_rtp_buffer_get_seq (&info->rtp),
fec_seq_base, TRUE);
if (fec_mask & packet_mask) {
fec_mask ^= packet_mask;
rtp_buffer_to_ulpfec_bitstring (&info->rtp, self->scratch_buf, FALSE,
fec_mask_long);
}
}
ret =
rtp_ulpfec_bitstring_to_media_rtp_buffer (self->scratch_buf,
fec_mask_long, ssrc, seq);
if (ret) {
/* We are about to put recovered packet back in self->info_media to be able
* to reuse it later for recovery of other packets
**/
gint i = self->info_arr->len;
RtpUlpFecMapInfo *info;
guint8 recovered_pt;
g_array_set_size (self->info_arr, self->info_arr->len + 1);
info = RTP_FEC_MAP_INFO_NTH (self, i);
if (!rtp_ulpfec_map_info_map (gst_buffer_ref (ret), info)) {
GST_WARNING_OBJECT (self, "Invalid recovered packet");
goto recovered_packet_invalid;
}
recovered_pt = gst_rtp_buffer_get_payload_type (&info->rtp);
if (!gst_rtp_ulpfec_dec_is_recovered_pt_valid (self, media_pt,
recovered_pt)) {
GST_WARNING_OBJECT (self,
"Recovered packet has unexpected payload type (%u)", recovered_pt);
goto recovered_packet_invalid;
}
GST_DEBUG_RTP_PACKET (self, "rtp header (recovered)", &info->rtp);
self->info_media =
g_list_insert_sorted_with_data (self->info_media, GUINT_TO_POINTER (i),
_compare_fec_map_info, self);
*dst_pt = recovered_pt;
}
return ret;
recovered_packet_invalid:
g_array_set_size (self->info_arr, self->info_arr->len - 1);
gst_buffer_unref (ret);
return NULL;
}
static GstBuffer *
gst_rtp_ulpfec_dec_recover_from_storage (GstRtpUlpFecDec * self,
guint8 * dst_pt, guint16 * dst_seq)
{
RtpUlpFecMapInfo *info;
if (self->lost_packet_returned)
return NULL;
g_assert (g_list_length (self->info_media) == 1);
info = RTP_FEC_MAP_INFO_NTH (self, self->info_media->data);
*dst_seq = gst_rtp_buffer_get_seq (&info->rtp);
*dst_pt = gst_rtp_buffer_get_payload_type (&info->rtp);
self->lost_packet_returned = TRUE;
GST_DEBUG_RTP_PACKET (self, "rtp header (recovered)", &info->rtp);
return gst_buffer_ref (info->rtp.buffer);
}
/* __has_builtin only works with clang, so test compiler version for gcc */
/* Intel compiler and MSVC probably have their own things as well */
/* TODO: make sure we use builtin for clang as well */
#if defined(__GNUC__) && __GNUC__ >= 4
#define rtp_ulpfec_ctz64 __builtin_ctzll
#else
static inline gint
rtp_ulpfec_ctz64_inline (guint64 mask)
{
gint nth_bit = 0;
do {
if ((mask & 1))
return nth_bit;
mask = mask >> 1;
} while (++nth_bit < 64);
return -1; /* should not be reached, since mask must not be 0 */
}
#define rtp_ulpfec_ctz64 rtp_ulpfec_ctz64_inline
#endif
static GstBuffer *
gst_rtp_ulpfec_dec_recover (GstRtpUlpFecDec * self, guint32 ssrc, gint media_pt,
guint8 * dst_pt, guint16 * dst_seq)
{
guint64 media_mask = 0;
gint media_mask_seq_base = -1;
gsize i;
if (self->lost_packet_from_storage)
return gst_rtp_ulpfec_dec_recover_from_storage (self, dst_pt, dst_seq);
/* Looking for a FEC packet which can be used for recovery */
for (i = 0; i < self->info_fec->len; ++i) {
RtpUlpFecMapInfo *info = RTP_FEC_MAP_INFO_NTH (self,
g_ptr_array_index (self->info_fec, i));
guint16 seq_base = rtp_ulpfec_buffer_get_seq_base (&info->rtp);
guint64 fec_mask = rtp_ulpfec_buffer_get_mask (&info->rtp);
guint64 missing_packets_mask;
if (media_mask_seq_base != (gint) seq_base) {
media_mask_seq_base = seq_base;
media_mask = gst_rtp_ulpfec_dec_get_media_buffers_mask (self, seq_base);
}
/* media_mask has 1s if packet exist.
* fec_mask is the mask of protected packets
* The statement below excludes existing packets from the protected. So
* we are left with 1s only for missing packets which can be recovered
* by this FEC packet. */
missing_packets_mask = fec_mask & (~media_mask);
/* Do we have any 1s? Checking if current FEC packet can be used for recovery */
if (0 != missing_packets_mask) {
guint trailing_zeros = rtp_ulpfec_ctz64 (missing_packets_mask);
/* Is it the only 1 in the mask? Checking if we lacking single packet in
* that case FEC packet can be used for recovery */
if (missing_packets_mask == (G_GUINT64_CONSTANT (1) << trailing_zeros)) {
GstBuffer *ret;
*dst_seq =
seq_base + (RTP_ULPFEC_SEQ_BASE_OFFSET_MAX (TRUE) - trailing_zeros);
ret =
gst_rtp_ulpfec_dec_recover_from_fec (self, info, ssrc, media_pt,
*dst_seq, dst_pt);
if (ret)
return ret;
}
}
}
return NULL;
}
static GstFlowReturn
gst_rtp_ulpfec_dec_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
GstRtpUlpFecDec *self = GST_RTP_ULPFEC_DEC (parent);
if (G_LIKELY (GST_FLOW_OK == self->chain_return_val)) {
if (G_UNLIKELY (self->unset_discont_flag)) {
self->unset_discont_flag = FALSE;
buf = gst_buffer_make_writable (buf);
GST_BUFFER_FLAG_UNSET (buf, GST_BUFFER_FLAG_DISCONT);
}
return gst_pad_push (self->srcpad, buf);
}
gst_buffer_unref (buf);
return self->chain_return_val;
}
static gboolean
gst_rtp_ulpfec_dec_handle_packet_loss (GstRtpUlpFecDec * self, guint16 seqnum,
GstClockTime timestamp, GstClockTime duration)
{
gint caps_pt = self->have_caps_pt ? self->caps_pt : -1;
gboolean ret = TRUE;
GstBufferList *buflist =
rtp_storage_get_packets_for_recovery (self->storage, self->fec_pt,
self->caps_ssrc, seqnum);
if (buflist) {
GstBuffer *recovered_buffer = NULL;
guint16 recovered_seq = 0;
guint8 recovered_pt = 0;
gst_rtp_ulpfec_dec_start (self, buflist, self->fec_pt, seqnum);
while (NULL != (recovered_buffer =
gst_rtp_ulpfec_dec_recover (self, self->caps_ssrc, caps_pt,
&recovered_pt, &recovered_seq))) {
if (seqnum == recovered_seq) {
recovered_buffer = gst_buffer_make_writable (recovered_buffer);
GST_BUFFER_PTS (recovered_buffer) = timestamp;
/* GST_BUFFER_DURATION (recovered_buffer) = duration;
* JB does not set the duration, so we will not too */
if (!self->lost_packet_from_storage)
rtp_storage_put_recovered_packet (self->storage,
gst_buffer_ref (recovered_buffer), recovered_pt, self->caps_ssrc,
recovered_seq);
GST_DEBUG_OBJECT (self,
"Pushing recovered packet ssrc=0x%08x seq=%u %" GST_PTR_FORMAT,
self->caps_ssrc, seqnum, recovered_buffer);
ret = FALSE;
self->unset_discont_flag = TRUE;
self->chain_return_val = gst_pad_push (self->srcpad, recovered_buffer);
break;
}
rtp_storage_put_recovered_packet (self->storage,
recovered_buffer, recovered_pt, self->caps_ssrc, recovered_seq);
}
gst_rtp_ulpfec_dec_stop (self);
gst_buffer_list_unref (buflist);
}
GST_DEBUG_OBJECT (self, "Packet lost ssrc=0x%08x seq=%u", self->caps_ssrc,
seqnum);
return ret;
}
static gboolean
gst_rtp_ulpfec_dec_handle_sink_event (GstPad * pad, GstObject * parent,
GstEvent * event)
{
GstRtpUlpFecDec *self = GST_RTP_ULPFEC_DEC (parent);
gboolean forward = TRUE;
GST_LOG_OBJECT (self, "Received event %" GST_PTR_FORMAT, event);
if (GST_FLOW_OK == self->chain_return_val &&
GST_EVENT_CUSTOM_DOWNSTREAM == GST_EVENT_TYPE (event) &&
gst_event_has_name (event, "GstRTPPacketLost")) {
guint seqnum;
GstClockTime timestamp, duration;
g_assert (self->have_caps_ssrc);
g_assert (self->storage);
if (!gst_structure_get (gst_event_get_structure (event),
"seqnum", G_TYPE_UINT, &seqnum,
"timestamp", G_TYPE_UINT64, &timestamp,
"duration", G_TYPE_UINT64, &duration, NULL))
g_assert_not_reached ();
forward =
gst_rtp_ulpfec_dec_handle_packet_loss (self, seqnum, timestamp,
duration);
if (forward)
++self->packets_unrecovered;
else
++self->packets_recovered;
GST_DEBUG_OBJECT (self, "Unrecovered / Recovered: %lu / %lu",
(gulong) self->packets_unrecovered, (gulong) self->packets_recovered);
} else if (GST_EVENT_CAPS == GST_EVENT_TYPE (event)) {
GstCaps *caps;
gboolean have_caps_pt = FALSE;
gboolean have_caps_ssrc = FALSE;
guint caps_ssrc = 0;
gint caps_pt = 0;
gst_event_parse_caps (event, &caps);
have_caps_ssrc =
gst_structure_get_uint (gst_caps_get_structure (caps, 0), "ssrc",
&caps_ssrc);
have_caps_pt =
gst_structure_get_int (gst_caps_get_structure (caps, 0), "payload",
&caps_pt);
if (self->have_caps_ssrc != have_caps_ssrc || self->caps_ssrc != caps_ssrc)
GST_DEBUG_OBJECT (self, "SSRC changed %u, 0x%08x -> %u, 0x%08x",
self->have_caps_ssrc, self->caps_ssrc, have_caps_ssrc, caps_ssrc);
if (self->have_caps_pt != have_caps_pt || self->caps_pt != caps_pt)
GST_DEBUG_OBJECT (self, "PT changed %u, %u -> %u, %u",
self->have_caps_pt, self->caps_pt, have_caps_pt, caps_pt);
self->have_caps_ssrc = have_caps_ssrc;
self->have_caps_pt = have_caps_pt;
self->caps_ssrc = caps_ssrc;
self->caps_pt = caps_pt;
}
if (forward)
return gst_pad_push_event (self->srcpad, event);
gst_event_unref (event);
return TRUE;
}
static void
gst_rtp_ulpfec_dec_init (GstRtpUlpFecDec * 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_DEBUG_FUNCPTR (gst_rtp_ulpfec_dec_chain));
gst_pad_set_event_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_rtp_ulpfec_dec_handle_sink_event));
gst_element_add_pad (GST_ELEMENT (self), self->srcpad);
gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
self->fec_pt = DEFAULT_FEC_PT;
self->chain_return_val = GST_FLOW_OK;
self->have_caps_ssrc = FALSE;
self->caps_ssrc = 0;
self->info_fec = g_ptr_array_new ();
self->info_arr = g_array_new (FALSE, TRUE, sizeof (RtpUlpFecMapInfo));
g_array_set_clear_func (self->info_arr,
(GDestroyNotify) rtp_ulpfec_map_info_unmap);
self->scratch_buf = g_array_new (FALSE, TRUE, sizeof (guint8));
}
static void
gst_rtp_ulpfec_dec_dispose (GObject * obj)
{
GstRtpUlpFecDec *self = GST_RTP_ULPFEC_DEC (obj);
GST_INFO_OBJECT (self,
" ssrc=0x%08x pt=%u"
" packets_recovered=%" G_GSIZE_FORMAT
" packets_unrecovered=%" G_GSIZE_FORMAT,
self->caps_ssrc, self->caps_pt,
self->packets_recovered, self->packets_unrecovered);
if (self->storage)
g_object_unref (self->storage);
g_assert (NULL == self->info_media);
g_assert (0 == self->info_fec->len);
g_assert (0 == self->info_arr->len);
if (self->fec_packets_received) {
GST_INFO_OBJECT (self,
" fec_packets_received=%" G_GSIZE_FORMAT
" fec_packets_rejected=%" G_GSIZE_FORMAT
" packets_rejected=%" G_GSIZE_FORMAT,
self->fec_packets_received,
self->fec_packets_rejected, self->packets_rejected);
}
g_ptr_array_free (self->info_fec, TRUE);
g_array_free (self->info_arr, TRUE);
g_array_free (self->scratch_buf, TRUE);
G_OBJECT_CLASS (gst_rtp_ulpfec_dec_parent_class)->dispose (obj);
}
static void
gst_rtp_ulpfec_dec_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstRtpUlpFecDec *self = GST_RTP_ULPFEC_DEC (object);
switch (prop_id) {
case PROP_PT:
self->fec_pt = g_value_get_uint (value);
break;
case PROP_STORAGE:
if (self->storage)
g_object_unref (self->storage);
self->storage = g_value_get_object (value);
if (self->storage)
g_object_ref (self->storage);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_rtp_ulpfec_dec_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstRtpUlpFecDec *self = GST_RTP_ULPFEC_DEC (object);
switch (prop_id) {
case PROP_PT:
g_value_set_uint (value, self->fec_pt);
break;
case PROP_STORAGE:
g_value_set_object (value, self->storage);
break;
case PROP_RECOVERED:
g_value_set_uint (value, (guint) self->packets_recovered);
break;
case PROP_UNRECOVERED:
g_value_set_uint (value, (guint) self->packets_unrecovered);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_rtp_ulpfec_dec_class_init (GstRtpUlpFecDecClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
GST_DEBUG_CATEGORY_INIT (gst_rtp_ulpfec_dec_debug,
"rtpulpfecdec", 0, "RTP FEC Decoder");
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 FEC Decoder",
"Codec/Depayloader/Network/RTP",
"Decodes RTP FEC (RFC5109)", "Mikhail Fludkov <misha@pexip.com>");
gobject_class->set_property =
GST_DEBUG_FUNCPTR (gst_rtp_ulpfec_dec_set_property);
gobject_class->get_property =
GST_DEBUG_FUNCPTR (gst_rtp_ulpfec_dec_get_property);
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_rtp_ulpfec_dec_dispose);
klass_properties[PROP_PT] = g_param_spec_uint ("pt", "pt",
"FEC packets payload type", 0, 127,
DEFAULT_FEC_PT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
klass_properties[PROP_STORAGE] =
g_param_spec_object ("storage", "RTP storage", "RTP storage",
G_TYPE_OBJECT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
klass_properties[PROP_RECOVERED] =
g_param_spec_uint ("recovered", "recovered",
"The number of recovered packets", 0, G_MAXUINT, 0,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
klass_properties[PROP_UNRECOVERED] =
g_param_spec_uint ("unrecovered", "unrecovered",
"The number of unrecovered packets", 0, G_MAXUINT, 0,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (gobject_class, N_PROPERTIES,
klass_properties);
g_assert (rtp_ulpfec_ctz64 (G_GUINT64_CONSTANT (0x1)) == 0);
g_assert (rtp_ulpfec_ctz64 (G_GUINT64_CONSTANT (0x8000000000000000)) == 63);
}