/* 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-rtpulpfecenc * @short_description: Generic RTP Forward Error Correction (FEC) encoder * @title: rtpulpfecenc * * Generic Forward Error Correction (FEC) encoder using Uneven Level * Protection (ULP) as described in RFC 5109. * * It differs from the RFC in one important way, it multiplexes the * FEC packets in the same sequence number as media packets. This is to be * compatible with libwebrtc as using in Google Chrome and with Microsoft * Lync / Skype for Business. * * Be warned that after using this element, it is no longer possible to know if * there is a gap in the media stream based on the sequence numbers as the FEC * packets become interleaved with the media packets. * * This element will insert protection packets in any RTP stream, which * can then be used on the receiving side to recover lost packets. * * This element rewrites packets' seqnums, which means that when combined * with retransmission elements such as #GstRtpRtxSend, it *must* be * placed upstream of those, otherwise retransmission requests will request * incorrect seqnums. * * A payload type for the protection packets *must* be specified, different * from the payload type of the protected packets, with the GstRtpUlpFecEnc:pt * property. * * The marker bit of RTP packets is used to determine sets of packets to * protect as a unit, in order to modulate the level of protection, this * behaviour can be disabled with GstRtpUlpFecEnc:multipacket, but should * be left enabled for video streams. * * The level of protection can be configured with two properties, * #GstRtpUlpFecEnc:percentage and #GstRtpUlpFecEnc:percentage-important, * the element will determine which percentage to use for a given set of * packets based on the presence of the #GST_BUFFER_FLAG_NON_DROPPABLE * flag, upstream payloaders are expected to set this flag on "important" * packets such as those making up a keyframe. * * The percentage is expressed not in terms of bytes, but in terms of * packets, this for implementation convenience. The drawback with this * approach is that when using a percentage different from 100 %, and a * low bitrate, entire frames may be contained in a single packet, leading * to some packets not being protected, thus lowering the overall recovery * rate on the receiving side. * * When using #GstRtpBin, this element should be inserted through the * #GstRtpBin::request-fec-encoder signal. * * * * Example pipeline * |[ * gst-launch-1.0 videotestsrc ! x264enc ! video/x-h264, profile=baseline ! rtph264pay pt=96 ! rtpulpfecenc percentage=100 pt=122 ! udpsink port=8888 * ]| This example will receive a stream with FEC and try to reconstruct the packets. * * Example programs are available at * rtpfecserver.rs * and * rtpfecclient.rs * * * See also: #GstRtpUlpFecDec, #GstRtpBin * Since: 1.14 */ #include #include #include #include "rtpulpfeccommon.h" #include "gstrtpulpfecenc.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")); #define UNDEF_PT 255 #define DEFAULT_PT UNDEF_PT #define DEFAULT_PCT 0 #define DEFAULT_PCT_IMPORTANT 0 #define DEFAULT_MULTIPACKET TRUE #define PACKETS_BUF_MAX_LENGTH (RTP_ULPFEC_PROTECTED_PACKETS_MAX(TRUE)) GST_DEBUG_CATEGORY (gst_rtp_ulpfec_enc_debug); #define GST_CAT_DEFAULT (gst_rtp_ulpfec_enc_debug) G_DEFINE_TYPE (GstRtpUlpFecEnc, gst_rtp_ulpfec_enc, GST_TYPE_ELEMENT); enum { PROP_0, PROP_PT, PROP_MULTIPACKET, PROP_PROTECTED, PROP_PERCENTAGE, PROP_PERCENTAGE_IMPORTANT, }; #define RTP_FEC_MAP_INFO_NTH(ctx, data) (&g_array_index (\ ((GstRtpUlpFecEncStreamCtx *)ctx)->info_arr, \ RtpUlpFecMapInfo, \ GPOINTER_TO_UINT(data))) static void gst_rtp_ulpfec_enc_stream_ctx_start (GstRtpUlpFecEncStreamCtx * ctx, GQueue * packets, guint fec_packets) { GList *it = packets->tail; guint i; g_array_set_size (ctx->info_arr, packets->length); for (i = 0; i < packets->length; ++i) { GstBuffer *buffer = it->data; RtpUlpFecMapInfo *info = RTP_FEC_MAP_INFO_NTH (ctx, i); if (!rtp_ulpfec_map_info_map (gst_buffer_ref (buffer), info)) g_assert_not_reached (); GST_LOG_RTP_PACKET (ctx->parent, "rtp header (incoming)", &info->rtp); it = g_list_previous (it); } ctx->fec_packets = fec_packets; ctx->fec_packet_idx = 0; } static void gst_rtp_ulpfec_enc_stream_ctx_stop (GstRtpUlpFecEncStreamCtx * ctx) { g_array_set_size (ctx->info_arr, 0); g_array_set_size (ctx->scratch_buf, 0); ctx->fec_packets = 0; ctx->fec_packet_idx = 0; } static void gst_rtp_ulpfec_enc_stream_ctx_get_protection_parameters (GstRtpUlpFecEncStreamCtx * ctx, guint16 * dst_seq_base, guint64 * dst_mask, guint * dst_start, guint * dst_end) { guint media_packets = ctx->info_arr->len; guint start = ctx->fec_packet_idx * media_packets / ctx->fec_packets; guint end = ((ctx->fec_packet_idx + 1) * media_packets + ctx->fec_packets - 1) / ctx->fec_packets - 1; guint len = end - start + 1; guint64 mask = 0; guint16 seq_base = 0; guint i; len = MIN (len, RTP_ULPFEC_PROTECTED_PACKETS_MAX (TRUE)); end = start + len - 1; for (i = start; i <= end; ++i) { RtpUlpFecMapInfo *info = RTP_FEC_MAP_INFO_NTH (ctx, i); guint16 seq = gst_rtp_buffer_get_seq (&info->rtp); if (mask) { gint diff = gst_rtp_buffer_compare_seqnum (seq_base, seq); if (diff < 0) { seq_base = seq; mask = mask >> (-diff); } mask |= rtp_ulpfec_packet_mask_from_seqnum (seq, seq_base, TRUE); } else { seq_base = seq; mask = rtp_ulpfec_packet_mask_from_seqnum (seq, seq_base, TRUE); } } *dst_start = start; *dst_end = end; *dst_mask = mask; *dst_seq_base = seq_base; } static GstBuffer * gst_rtp_ulpfec_enc_stream_ctx_protect (GstRtpUlpFecEncStreamCtx * ctx, guint8 pt, guint16 seq, guint32 timestamp, guint32 ssrc) { guint end = 0; guint start = 0; guint64 fec_mask = 0; guint16 seq_base = 0; GstBuffer *ret; guint64 tmp_mask; gboolean fec_mask_long; guint i; if (ctx->fec_packet_idx >= ctx->fec_packets) return NULL; g_array_set_size (ctx->scratch_buf, 0); gst_rtp_ulpfec_enc_stream_ctx_get_protection_parameters (ctx, &seq_base, &fec_mask, &start, &end); tmp_mask = fec_mask; fec_mask_long = rtp_ulpfec_mask_is_long (fec_mask); for (i = start; i <= end; ++i) { RtpUlpFecMapInfo *info = RTP_FEC_MAP_INFO_NTH (ctx, i); guint64 packet_mask = rtp_ulpfec_packet_mask_from_seqnum (gst_rtp_buffer_get_seq (&info->rtp), seq_base, TRUE); if (tmp_mask & packet_mask) { tmp_mask ^= packet_mask; rtp_buffer_to_ulpfec_bitstring (&info->rtp, ctx->scratch_buf, FALSE, fec_mask_long); } } g_assert (tmp_mask == 0); ret = rtp_ulpfec_bitstring_to_fec_rtp_buffer (ctx->scratch_buf, seq_base, fec_mask_long, fec_mask, FALSE, pt, seq, timestamp, ssrc); ++ctx->fec_packet_idx; return ret; } static void gst_rtp_ulpfec_enc_stream_ctx_report_budget (GstRtpUlpFecEncStreamCtx * ctx) { GST_TRACE_OBJECT (ctx->parent, "budget = %f budget_important = %f", ctx->budget, ctx->budget_important); } static void gst_rtp_ulpfec_enc_stream_ctx_increment_budget (GstRtpUlpFecEncStreamCtx * ctx, GstBuffer * buffer) { if (ctx->percentage == 0 && ctx->percentage_important == 0) { if (ctx->budget > 0) { ctx->budget = 0; ctx->budget_important = 0; } if (ctx->budget < 0) ctx->budget += ctx->budget_inc; return; } ctx->budget += ctx->budget_inc; if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_NON_DROPPABLE)) { ctx->budget_important += ctx->budget_inc_important; } gst_rtp_ulpfec_enc_stream_ctx_report_budget (ctx); } static void gst_rtp_ulpfec_enc_stream_ctx_decrement_budget (GstRtpUlpFecEncStreamCtx * ctx, guint fec_packets_num) { if (ctx->budget_important >= 1.) ctx->budget_important -= fec_packets_num; ctx->budget -= fec_packets_num; gst_rtp_ulpfec_enc_stream_ctx_report_budget (ctx); } static guint gst_rtp_ulpfec_enc_stream_ctx_get_fec_packets_num (GstRtpUlpFecEncStreamCtx * ctx) { g_assert_cmpfloat (ctx->budget_important, >=, 0.); if (ctx->budget_important >= 1.) return ctx->budget_important; return ctx->budget > 0. ? (guint) ctx->budget : 0; } static void gst_rtp_ulpfec_enc_stream_ctx_free_packets_buf (GstRtpUlpFecEncStreamCtx * ctx) { while (ctx->packets_buf.length) gst_buffer_unref (g_queue_pop_tail (&ctx->packets_buf)); } static void gst_rtp_ulpfec_enc_stream_ctx_prepend_to_fec_buffer (GstRtpUlpFecEncStreamCtx * ctx, GstRTPBuffer * rtp, guint buf_max_size) { GList *new_head; if (ctx->packets_buf.length == buf_max_size) { new_head = g_queue_pop_tail_link (&ctx->packets_buf); } else { new_head = g_list_alloc (); } gst_buffer_replace ((GstBuffer **) & new_head->data, rtp->buffer); g_queue_push_head_link (&ctx->packets_buf, new_head); g_assert_cmpint (ctx->packets_buf.length, <=, buf_max_size); } static GstFlowReturn gst_rtp_ulpfec_enc_stream_ctx_push_fec_packets (GstRtpUlpFecEncStreamCtx * ctx, guint8 pt, guint16 seq, guint32 timestamp, guint32 ssrc) { GstFlowReturn ret = GST_FLOW_OK; guint fec_packets_num = gst_rtp_ulpfec_enc_stream_ctx_get_fec_packets_num (ctx); if (fec_packets_num) { guint fec_packets_pushed = 0; GstBuffer *latest_packet = ctx->packets_buf.head->data; GstBuffer *fec = NULL; gst_rtp_ulpfec_enc_stream_ctx_start (ctx, &ctx->packets_buf, fec_packets_num); while (NULL != (fec = gst_rtp_ulpfec_enc_stream_ctx_protect (ctx, pt, seq + fec_packets_pushed, timestamp, ssrc))) { gst_buffer_copy_into (fec, latest_packet, GST_BUFFER_COPY_TIMESTAMPS, 0, -1); ret = gst_pad_push (ctx->srcpad, fec); if (GST_FLOW_OK == ret) ++fec_packets_pushed; else break; } gst_rtp_ulpfec_enc_stream_ctx_stop (ctx); g_assert_cmpint (fec_packets_pushed, <=, fec_packets_num); ctx->num_packets_protected += ctx->packets_buf.length; ctx->num_packets_fec += fec_packets_pushed; ctx->seqnum_offset += fec_packets_pushed; ctx->seqnum += fec_packets_pushed; } gst_rtp_ulpfec_enc_stream_ctx_decrement_budget (ctx, fec_packets_num); return ret; } static void gst_rtp_ulpfec_enc_stream_ctx_cache_packet (GstRtpUlpFecEncStreamCtx * ctx, GstRTPBuffer * rtp, gboolean * dst_empty_packet_buffer, gboolean * dst_push_fec) { if (ctx->multipacket) { gst_rtp_ulpfec_enc_stream_ctx_prepend_to_fec_buffer (ctx, rtp, PACKETS_BUF_MAX_LENGTH); gst_rtp_ulpfec_enc_stream_ctx_increment_budget (ctx, rtp->buffer); *dst_empty_packet_buffer = gst_rtp_buffer_get_marker (rtp); *dst_push_fec = *dst_empty_packet_buffer; } else { gboolean push_fec; gst_rtp_ulpfec_enc_stream_ctx_prepend_to_fec_buffer (ctx, rtp, 1); push_fec = ctx->fec_nth == 0 ? FALSE : 0 == (ctx->num_packets_received % ctx->fec_nth); ctx->budget = push_fec ? 1 : 0; ctx->budget_important = 0; *dst_push_fec = push_fec; *dst_empty_packet_buffer = FALSE; } } static void gst_rtp_ulpfec_enc_stream_ctx_configure (GstRtpUlpFecEncStreamCtx * ctx, guint pt, guint percentage, guint percentage_important, gboolean multipacket) { ctx->pt = pt; ctx->percentage = percentage; ctx->percentage_important = percentage_important; ctx->multipacket = multipacket; ctx->fec_nth = percentage ? 100 / percentage : 0; if (percentage) { ctx->budget_inc = percentage / 100.; ctx->budget_inc_important = percentage > percentage_important ? ctx->budget_inc : percentage_important / 100.; } /* else { ctx->budget_inc = 0.0; } */ ctx->budget_inc_important = percentage > percentage_important ? ctx->budget_inc : percentage_important / 100.; } static GstRtpUlpFecEncStreamCtx * gst_rtp_ulpfec_enc_stream_ctx_new (guint ssrc, GstElement * parent, GstPad * srcpad, guint pt, guint percentage, guint percentage_important, gboolean multipacket) { GstRtpUlpFecEncStreamCtx *ctx = g_new0 (GstRtpUlpFecEncStreamCtx, 1); ctx->ssrc = ssrc; ctx->parent = parent; ctx->srcpad = srcpad; ctx->seqnum = g_random_int_range (0, G_MAXUINT16 / 2); ctx->info_arr = g_array_new (FALSE, TRUE, sizeof (RtpUlpFecMapInfo)); g_array_set_clear_func (ctx->info_arr, (GDestroyNotify) rtp_ulpfec_map_info_unmap); ctx->parent = parent; ctx->scratch_buf = g_array_new (FALSE, TRUE, sizeof (guint8)); gst_rtp_ulpfec_enc_stream_ctx_configure (ctx, pt, percentage, percentage_important, multipacket); return ctx; } static void gst_rtp_ulpfec_enc_stream_ctx_free (GstRtpUlpFecEncStreamCtx * ctx) { if (ctx->num_packets_received) { GST_INFO_OBJECT (ctx->parent, "Actual FEC overhead is %4.2f%% (%u/%u)\n", ctx->num_packets_fec * (double) 100. / ctx->num_packets_received, ctx->num_packets_fec, ctx->num_packets_received); } gst_rtp_ulpfec_enc_stream_ctx_free_packets_buf (ctx); g_assert (0 == ctx->info_arr->len); g_array_free (ctx->info_arr, TRUE); g_array_free (ctx->scratch_buf, TRUE); g_slice_free1 (sizeof (GstRtpUlpFecEncStreamCtx), ctx); } static GstFlowReturn gst_rtp_ulpfec_enc_stream_ctx_process (GstRtpUlpFecEncStreamCtx * ctx, GstBuffer * buffer) { GstRTPBuffer rtp = GST_RTP_BUFFER_INIT; GstFlowReturn ret; gboolean push_fec = FALSE; gboolean empty_packet_buffer = FALSE; ctx->num_packets_received++; if (ctx->seqnum_offset > 0) { buffer = gst_buffer_make_writable (buffer); if (!gst_rtp_buffer_map (buffer, GST_MAP_READWRITE | GST_RTP_BUFFER_MAP_FLAG_SKIP_PADDING, &rtp)) g_assert_not_reached (); gst_rtp_buffer_set_seq (&rtp, gst_rtp_buffer_get_seq (&rtp) + ctx->seqnum_offset); } else { if (!gst_rtp_buffer_map (buffer, GST_MAP_READ | GST_RTP_BUFFER_MAP_FLAG_SKIP_PADDING, &rtp)) g_assert_not_reached (); } gst_rtp_ulpfec_enc_stream_ctx_cache_packet (ctx, &rtp, &empty_packet_buffer, &push_fec); if (push_fec) { guint32 fec_timestamp = gst_rtp_buffer_get_timestamp (&rtp); guint32 fec_ssrc = gst_rtp_buffer_get_ssrc (&rtp); guint16 fec_seq = gst_rtp_buffer_get_seq (&rtp) + 1; gst_rtp_buffer_unmap (&rtp); ret = gst_pad_push (ctx->srcpad, buffer); if (GST_FLOW_OK == ret) ret = gst_rtp_ulpfec_enc_stream_ctx_push_fec_packets (ctx, ctx->pt, fec_seq, fec_timestamp, fec_ssrc); } else { gst_rtp_buffer_unmap (&rtp); ret = gst_pad_push (ctx->srcpad, buffer); } if (empty_packet_buffer) gst_rtp_ulpfec_enc_stream_ctx_free_packets_buf (ctx); return ret; } static GstRtpUlpFecEncStreamCtx * gst_rtp_ulpfec_enc_aquire_ctx (GstRtpUlpFecEnc * fec, guint ssrc) { GstRtpUlpFecEncStreamCtx *ctx; GST_OBJECT_LOCK (fec); ctx = g_hash_table_lookup (fec->ssrc_to_ctx, GUINT_TO_POINTER (ssrc)); if (ctx == NULL) { ctx = gst_rtp_ulpfec_enc_stream_ctx_new (ssrc, GST_ELEMENT_CAST (fec), fec->srcpad, fec->pt, fec->percentage, fec->percentage_important, fec->multipacket); g_hash_table_insert (fec->ssrc_to_ctx, GUINT_TO_POINTER (ssrc), ctx); } GST_OBJECT_UNLOCK (fec); return ctx; } static GstFlowReturn gst_rtp_ulpfec_enc_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer) { GstRtpUlpFecEnc *fec = GST_RTP_ULPFEC_ENC (parent); GstRTPBuffer rtp = GST_RTP_BUFFER_INIT; GstFlowReturn ret; guint ssrc = 0; GstRtpUlpFecEncStreamCtx *ctx; if (fec->pt == UNDEF_PT) return gst_pad_push (fec->srcpad, buffer); /* FIXME: avoid this additional mapping of the buffer to get the ssrc! */ if (!gst_rtp_buffer_map (buffer, GST_MAP_READ | GST_RTP_BUFFER_MAP_FLAG_SKIP_PADDING, &rtp)) { g_assert_not_reached (); } ssrc = gst_rtp_buffer_get_ssrc (&rtp); gst_rtp_buffer_unmap (&rtp); ctx = gst_rtp_ulpfec_enc_aquire_ctx (fec, ssrc); ret = gst_rtp_ulpfec_enc_stream_ctx_process (ctx, buffer); /* FIXME: does not work for mulitple ssrcs */ fec->num_packets_protected = ctx->num_packets_protected; return ret; } static void gst_rtp_ulpfec_enc_configure_ctx (gpointer key, gpointer value, gpointer user_data) { GstRtpUlpFecEnc *fec = user_data; GstRtpUlpFecEncStreamCtx *ctx = value; gst_rtp_ulpfec_enc_stream_ctx_configure (ctx, fec->pt, fec->percentage, fec->percentage_important, fec->multipacket); } static void gst_rtp_ulpfec_enc_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstRtpUlpFecEnc *fec = GST_RTP_ULPFEC_ENC (object); switch (prop_id) { case PROP_PT: fec->pt = g_value_get_uint (value); break; case PROP_MULTIPACKET: fec->multipacket = g_value_get_boolean (value); break; case PROP_PERCENTAGE: fec->percentage = g_value_get_uint (value); break; case PROP_PERCENTAGE_IMPORTANT: fec->percentage_important = g_value_get_uint (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } GST_OBJECT_LOCK (fec); g_hash_table_foreach (fec->ssrc_to_ctx, gst_rtp_ulpfec_enc_configure_ctx, fec); GST_OBJECT_UNLOCK (fec); } static void gst_rtp_ulpfec_enc_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstRtpUlpFecEnc *fec = GST_RTP_ULPFEC_ENC (object); switch (prop_id) { case PROP_PT: g_value_set_uint (value, fec->pt); break; case PROP_PROTECTED: g_value_set_uint (value, fec->num_packets_protected); break; case PROP_PERCENTAGE: g_value_set_uint (value, fec->percentage); break; case PROP_PERCENTAGE_IMPORTANT: g_value_set_uint (value, fec->percentage_important); break; case PROP_MULTIPACKET: g_value_set_boolean (value, fec->multipacket); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_rtp_ulpfec_enc_dispose (GObject * obj) { GstRtpUlpFecEnc *fec = GST_RTP_ULPFEC_ENC (obj); g_hash_table_destroy (fec->ssrc_to_ctx); G_OBJECT_CLASS (gst_rtp_ulpfec_enc_parent_class)->dispose (obj); } static void gst_rtp_ulpfec_enc_init (GstRtpUlpFecEnc * fec) { fec->srcpad = gst_pad_new_from_static_template (&srctemplate, "src"); gst_element_add_pad (GST_ELEMENT (fec), fec->srcpad); fec->sinkpad = gst_pad_new_from_static_template (&sinktemplate, "sink"); GST_PAD_SET_PROXY_CAPS (fec->sinkpad); GST_PAD_SET_PROXY_ALLOCATION (fec->sinkpad); gst_pad_set_chain_function (fec->sinkpad, GST_DEBUG_FUNCPTR (gst_rtp_ulpfec_enc_chain)); gst_element_add_pad (GST_ELEMENT (fec), fec->sinkpad); fec->ssrc_to_ctx = g_hash_table_new_full (NULL, NULL, NULL, (GDestroyNotify) gst_rtp_ulpfec_enc_stream_ctx_free); } static void gst_rtp_ulpfec_enc_class_init (GstRtpUlpFecEncClass * klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); GstElementClass *element_class = GST_ELEMENT_CLASS (klass); GST_DEBUG_CATEGORY_INIT (gst_rtp_ulpfec_enc_debug, "rtpulpfecenc", 0, "FEC encoder element"); 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 Encoder", "Codec/Payloader/Network/RTP", "Encodes RTP FEC (RFC5109)", "Mikhail Fludkov "); gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_rtp_ulpfec_enc_set_property); gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_rtp_ulpfec_enc_get_property); gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_rtp_ulpfec_enc_dispose); g_object_class_install_property (gobject_class, PROP_PT, g_param_spec_uint ("pt", "payload type", "The payload type of FEC packets", 0, 255, DEFAULT_PT, G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_MULTIPACKET, g_param_spec_boolean ("multipacket", "Multipacket", "Apply FEC on multiple packets", DEFAULT_MULTIPACKET, G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_PERCENTAGE, g_param_spec_uint ("percentage", "Percentage", "FEC overhead percentage for the whole stream", 0, 100, DEFAULT_PCT, G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_PERCENTAGE_IMPORTANT, g_param_spec_uint ("percentage-important", "Percentage important", "FEC overhead percentage for important packets", 0, 100, DEFAULT_PCT_IMPORTANT, G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_PROTECTED, g_param_spec_uint ("protected", "Protected", "Count of protected packets", 0, G_MAXUINT32, 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS)); }