/* GStreamer * Copyright (C) <2020> Mathieu Duponchelle * * 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., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, USA. */ /** * SECTION:element-rtpst2022-1-fecdec * @see_also: #element-rtpst2022-1-fecenc * * This element takes as input a media stream and up to two FEC * streams as described in SMPTE 2022-1: Forward Error Correction * for Real-Time Video/Audio Transport Over IP Networks, and makes * use of the FEC packets to recover media packets that may have * gotten lost. * * ## Design * * The approach picked for this element is to proactively reconstruct missing * packets as soon as possible. When a FEC packet arrives, the element * immediately checks whether a media packet in the row / column it protects * can be reconstructed. * * Similarly, when a media packet comes in, the element checks whether it has * already received a corresponding packet in both the column and row the packet * belongs to, and if so goes through the first step listed above. * * This process is repeated recursively, allowing for recoveries over one * dimension to unblock recoveries over the other. * * In perfect networking conditions, this incurs next to no overhead as FEC * packets will arrive after the media packets, causing no reconstruction to * take place, just a few checks upon chaining. * * ## sender / receiver example * * ``` shell * gst-launch-1.0 \ * rtpbin name=rtp fec-encoders='fec,0="rtpst2022-1-fecenc\ rows\=5\ columns\=5";' \ * uridecodebin uri=file:///path/to/video/file ! x264enc key-int-max=60 tune=zerolatency ! \ * queue ! mpegtsmux ! rtpmp2tpay ssrc=0 ! rtp.send_rtp_sink_0 \ * rtp.send_rtp_src_0 ! udpsink host=127.0.0.1 port=5000 \ * rtp.send_fec_src_0_0 ! udpsink host=127.0.0.1 port=5002 async=false \ * rtp.send_fec_src_0_1 ! udpsink host=127.0.0.1 port=5004 async=false * ``` * * ``` shell * gst-launch-1.0 \ * rtpbin latency=500 fec-decoders='fec,0="rtpst2022-1-fecdec\ size-time\=1000000000";' name=rtp \ * udpsrc address=127.0.0.1 port=5002 caps="application/x-rtp, payload=96" ! queue ! rtp.recv_fec_sink_0_0 \ * udpsrc address=127.0.0.1 port=5004 caps="application/x-rtp, payload=96" ! queue ! rtp.recv_fec_sink_0_1 \ * udpsrc address=127.0.0.1 port=5000 caps="application/x-rtp, media=video, clock-rate=90000, encoding-name=mp2t, payload=33" ! \ * queue ! netsim drop-probability=0.05 ! rtp.recv_rtp_sink_0 \ * rtp. ! decodebin ! videoconvert ! queue ! autovideosink * ``` * * With the above command line, as the media packet size is constant, * the fec overhead can be approximated to the number of fec packets * per 2-d matrix of media packet, here 10 fec packets for each 25 * media packets. * * Increasing the number of rows and columns will decrease the overhead, * but obviously increase the likelihood of recovery failure for lost * packets on the receiver side. * * Since: 1.20 */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include "gstrtpst2022-1-fecdec.h" GST_DEBUG_CATEGORY_STATIC (gst_rtpst_2022_1_fecdec_debug); #define GST_CAT_DEFAULT gst_rtpst_2022_1_fecdec_debug #define DEFAULT_SIZE_TIME (GST_SECOND) typedef struct { guint16 seq; GstBuffer *buffer; } Item; static GstFlowReturn store_media_item (GstRTPST_2022_1_FecDec * dec, GstRTPBuffer * rtp, Item * item); static void free_item (Item * item) { gst_buffer_unref (item->buffer); item->buffer = NULL; g_free (item); } static gint cmp_items (Item * a, Item * b, gpointer unused) { return gst_rtp_buffer_compare_seqnum (b->seq, a->seq); } enum { PROP_0, PROP_SIZE_TIME, }; struct _GstRTPST_2022_1_FecDecClass { GstElementClass class; }; struct _GstRTPST_2022_1_FecDec { GstElement element; GstPad *srcpad; GstPad *sinkpad; GList *fec_sinkpads; /* All the following field are protected by the OBJECT_LOCK */ GSequence *packets; GHashTable *column_fec_packets; GSequence *fec_packets[2]; /* N columns */ guint l; /* N rows */ guint d; GstClockTime size_time; GstClockTime max_arrival_time; GstClockTime max_fec_arrival_time[2]; }; #define RTP_CAPS "application/x-rtp" typedef struct { guint16 seq; guint16 len; guint8 E; guint8 pt; guint32 mask; guint32 timestamp; guint8 N; guint8 D; guint8 type; guint8 index; guint8 offset; guint8 NA; guint8 seq_ext; guint8 *payload; guint payload_len; gboolean marker; gboolean padding; gboolean extension; } Rtp2DFecHeader; static GstStaticPadTemplate fec_sink_template = GST_STATIC_PAD_TEMPLATE ("fec_%u", GST_PAD_SINK, GST_PAD_REQUEST, GST_STATIC_CAPS (RTP_CAPS)); static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS (RTP_CAPS)); static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS (RTP_CAPS)); #define gst_rtpst_2022_1_fecdec_parent_class parent_class G_DEFINE_TYPE (GstRTPST_2022_1_FecDec, gst_rtpst_2022_1_fecdec, GST_TYPE_ELEMENT); static void trim_items (GstRTPST_2022_1_FecDec * dec) { GSequenceIter *tmp_iter, *iter = NULL; for (tmp_iter = g_sequence_get_begin_iter (dec->packets); tmp_iter; tmp_iter = g_sequence_iter_next (tmp_iter)) { Item *item; if (g_sequence_iter_is_end (tmp_iter)) break; item = g_sequence_get (tmp_iter); if (dec->max_arrival_time - GST_BUFFER_DTS_OR_PTS (item->buffer) < dec->size_time) break; iter = tmp_iter; } if (iter) { Item *item = g_sequence_get (iter); GST_TRACE_OBJECT (dec, "Trimming packets up to %" GST_TIME_FORMAT " (seq: %u)", GST_TIME_ARGS (GST_BUFFER_DTS_OR_PTS (item->buffer)), item->seq); g_sequence_remove_range (g_sequence_get_begin_iter (dec->packets), iter); } } static void trim_fec_items (GstRTPST_2022_1_FecDec * dec, guint D) { GSequenceIter *tmp_iter, *iter = NULL; for (tmp_iter = g_sequence_get_begin_iter (dec->fec_packets[D]); tmp_iter; tmp_iter = g_sequence_iter_next (tmp_iter)) { Item *item; if (g_sequence_iter_is_end (tmp_iter)) break; item = g_sequence_get (tmp_iter); if (dec->max_fec_arrival_time[D] - GST_BUFFER_DTS_OR_PTS (item->buffer) < dec->size_time) break; if (!D) { guint i; guint16 seq; for (i = 0; i < dec->d; i++) { seq = item->seq + i * dec->l; g_hash_table_remove (dec->column_fec_packets, GUINT_TO_POINTER (seq)); } } iter = tmp_iter; } if (iter) { Item *item = g_sequence_get (iter); GST_TRACE_OBJECT (dec, "Trimming %s FEC packets up to %" GST_TIME_FORMAT " (seq: %u)", D ? "row" : "column", GST_TIME_ARGS (GST_BUFFER_DTS_OR_PTS (item->buffer)), item->seq); g_sequence_remove_range (g_sequence_get_begin_iter (dec->fec_packets[D]), iter); } } static Item * lookup_media_packet (GstRTPST_2022_1_FecDec * dec, guint16 seqnum) { GSequenceIter *iter; Item *ret = NULL; Item dummy = { seqnum, NULL }; iter = g_sequence_lookup (dec->packets, &dummy, (GCompareDataFunc) cmp_items, NULL); if (iter) ret = g_sequence_get (iter); return ret; } static gboolean parse_header (GstRTPBuffer * rtp, Rtp2DFecHeader * fec) { gboolean ret = FALSE; GstBitReader bits; guint8 *data = gst_rtp_buffer_get_payload (rtp); guint len = gst_rtp_buffer_get_payload_len (rtp); if (len < 16) goto done; gst_bit_reader_init (&bits, data, len); fec->marker = gst_rtp_buffer_get_marker (rtp); fec->padding = gst_rtp_buffer_get_padding (rtp); fec->extension = gst_rtp_buffer_get_extension (rtp); fec->seq = gst_bit_reader_get_bits_uint16_unchecked (&bits, 16); fec->len = gst_bit_reader_get_bits_uint16_unchecked (&bits, 16); fec->E = gst_bit_reader_get_bits_uint8_unchecked (&bits, 1); fec->pt = gst_bit_reader_get_bits_uint8_unchecked (&bits, 7); fec->mask = gst_bit_reader_get_bits_uint32_unchecked (&bits, 24); fec->timestamp = gst_bit_reader_get_bits_uint32_unchecked (&bits, 32); fec->N = gst_bit_reader_get_bits_uint8_unchecked (&bits, 1); fec->D = gst_bit_reader_get_bits_uint8_unchecked (&bits, 1); fec->type = gst_bit_reader_get_bits_uint8_unchecked (&bits, 3); fec->index = gst_bit_reader_get_bits_uint8_unchecked (&bits, 3); fec->offset = gst_bit_reader_get_bits_uint8_unchecked (&bits, 8); fec->NA = gst_bit_reader_get_bits_uint8_unchecked (&bits, 8); fec->seq_ext = gst_bit_reader_get_bits_uint8_unchecked (&bits, 8); fec->payload = data + 16; fec->payload_len = len - 16; ret = TRUE; done: return ret; } static Item * get_row_fec (GstRTPST_2022_1_FecDec * dec, guint16 seqnum) { GSequenceIter *iter; Item *ret = NULL; Item dummy = { 0, }; if (dec->l == G_MAXUINT) goto done; /* Potential underflow is intended */ dummy.seq = seqnum - dec->l; iter = g_sequence_search (dec->fec_packets[1], &dummy, (GCompareDataFunc) cmp_items, NULL); if (!g_sequence_iter_is_end (iter)) { gint seqdiff; ret = g_sequence_get (iter); seqdiff = gst_rtp_buffer_compare_seqnum (ret->seq, seqnum); /* Now check whether the fec packet does apply */ if (seqdiff < 0 || seqdiff >= dec->l) ret = NULL; } done: return ret; } static Item * get_column_fec (GstRTPST_2022_1_FecDec * dec, guint16 seqnum) { Item *ret = NULL; if (dec->l == G_MAXUINT || dec->d == G_MAXUINT) goto done; ret = g_hash_table_lookup (dec->column_fec_packets, GUINT_TO_POINTER (seqnum)); done: return ret; } static void _xor_mem (guint8 * restrict dst, const guint8 * restrict src, gsize length) { guint i; for (i = 0; i < (length / sizeof (guint64)); ++i) { #if G_BYTE_ORDER == G_LITTLE_ENDIAN GST_WRITE_UINT64_LE (dst, GST_READ_UINT64_LE (dst) ^ GST_READ_UINT64_LE (src)); #else GST_WRITE_UINT64_BE (dst, GST_READ_UINT64_BE (dst) ^ GST_READ_UINT64_BE (src)); #endif dst += sizeof (guint64); src += sizeof (guint64); } for (i = 0; i < (length % sizeof (guint64)); ++i) dst[i] ^= src[i]; } static GstFlowReturn xor_items (GstRTPST_2022_1_FecDec * dec, Rtp2DFecHeader * fec, GList * packets, guint16 seqnum) { guint8 *xored; guint32 xored_timestamp; guint8 xored_pt; guint16 xored_payload_len; Item *item; GstRTPBuffer rtp = GST_RTP_BUFFER_INIT; GList *tmp; GstFlowReturn ret = GST_FLOW_OK; GstBuffer *buffer; gboolean xored_marker; gboolean xored_padding; gboolean xored_extension; /* Figure out the recovered packet length first */ xored_payload_len = fec->len; for (tmp = packets; tmp; tmp = tmp->next) { GstRTPBuffer media_rtp = GST_RTP_BUFFER_INIT; Item *item = (Item *) tmp->data; gst_rtp_buffer_map (item->buffer, GST_MAP_READ, &media_rtp); xored_payload_len ^= gst_rtp_buffer_get_payload_len (&media_rtp); gst_rtp_buffer_unmap (&media_rtp); } if (xored_payload_len > fec->payload_len) { GST_WARNING_OBJECT (dec, "FEC payload len %u < length recovery %u", fec->payload_len, xored_payload_len); goto done; } item = g_malloc0 (sizeof (Item)); item->seq = seqnum; item->buffer = gst_rtp_buffer_new_allocate (xored_payload_len, 0, 0); gst_rtp_buffer_map (item->buffer, GST_MAP_WRITE, &rtp); xored = gst_rtp_buffer_get_payload (&rtp); memcpy (xored, fec->payload, xored_payload_len); xored_timestamp = fec->timestamp; xored_pt = fec->pt; xored_marker = fec->marker; xored_padding = fec->padding; xored_extension = fec->extension; for (tmp = packets; tmp; tmp = tmp->next) { GstRTPBuffer media_rtp = GST_RTP_BUFFER_INIT; Item *item = (Item *) tmp->data; gst_rtp_buffer_map (item->buffer, GST_MAP_READ, &media_rtp); _xor_mem (xored, gst_rtp_buffer_get_payload (&media_rtp), MIN (gst_rtp_buffer_get_payload_len (&media_rtp), xored_payload_len)); xored_timestamp ^= gst_rtp_buffer_get_timestamp (&media_rtp); xored_pt ^= gst_rtp_buffer_get_payload_type (&media_rtp); xored_marker ^= gst_rtp_buffer_get_marker (&media_rtp); xored_padding ^= gst_rtp_buffer_get_padding (&media_rtp); xored_extension ^= gst_rtp_buffer_get_extension (&media_rtp); gst_rtp_buffer_unmap (&media_rtp); } GST_DEBUG_OBJECT (dec, "Recovered buffer through %s FEC with seqnum %u, payload len %u and timestamp %u", fec->D ? "row" : "column", seqnum, xored_payload_len, xored_timestamp); GST_BUFFER_DTS (item->buffer) = dec->max_arrival_time; gst_rtp_buffer_set_timestamp (&rtp, xored_timestamp); gst_rtp_buffer_set_seq (&rtp, seqnum); gst_rtp_buffer_set_payload_type (&rtp, xored_pt); gst_rtp_buffer_set_marker (&rtp, xored_marker); gst_rtp_buffer_set_padding (&rtp, xored_padding); gst_rtp_buffer_set_extension (&rtp, xored_extension); gst_rtp_buffer_unmap (&rtp); /* Store a ref on item->buffer as store_media_item may * recurse and call this method again, potentially releasing * the object lock and leaving our item unprotected in * dec->packets */ buffer = gst_buffer_ref (item->buffer); /* It is right that we should celebrate, * for your brother was dead, and is alive again */ gst_rtp_buffer_map (item->buffer, GST_MAP_READ, &rtp); ret = store_media_item (dec, &rtp, item); gst_rtp_buffer_unmap (&rtp); if (ret == GST_FLOW_OK) { /* Unlocking here is safe */ GST_OBJECT_UNLOCK (dec); ret = gst_pad_push (dec->srcpad, buffer); GST_OBJECT_LOCK (dec); } else { gst_buffer_unref (buffer); } done: return ret; } /* Returns a flow value if we should discard the packet, GST_FLOW_CUSTOM_SUCCESS otherwise */ static GstFlowReturn check_fec (GstRTPST_2022_1_FecDec * dec, Rtp2DFecHeader * fec) { GList *packets = NULL; gint missing_seq = -1; guint n_packets = 0; guint required_n_packets; GstFlowReturn ret = GST_FLOW_OK; if (fec->D) { guint i = 0; required_n_packets = dec->l; for (i = 0; i < dec->l; i++) { Item *item = lookup_media_packet (dec, fec->seq + i); if (item) { packets = g_list_prepend (packets, item); n_packets += 1; } else { missing_seq = fec->seq + i; } } } else { guint i = 0; required_n_packets = dec->d; for (i = 0; i < dec->d; i++) { Item *item = lookup_media_packet (dec, fec->seq + i * dec->l); if (item) { packets = g_list_prepend (packets, item); n_packets += 1; } else { missing_seq = fec->seq + i * dec->l; } } } if (n_packets == required_n_packets) { g_assert (missing_seq == -1); GST_LOG_OBJECT (dec, "All media packets present, we can discard that FEC packet"); } else if (n_packets + 1 == required_n_packets) { g_assert (missing_seq != -1); ret = xor_items (dec, fec, packets, missing_seq); GST_LOG_OBJECT (dec, "We have enough info to reconstruct %u", missing_seq); } else { ret = GST_FLOW_CUSTOM_SUCCESS; GST_LOG_OBJECT (dec, "Too many media packets missing, storing FEC packet"); } g_list_free (packets); return ret; } static GstFlowReturn check_fec_item (GstRTPST_2022_1_FecDec * dec, Item * item) { Rtp2DFecHeader fec; GstRTPBuffer rtp = GST_RTP_BUFFER_INIT; GstFlowReturn ret; gst_rtp_buffer_map (item->buffer, GST_MAP_READ, &rtp); parse_header (&rtp, &fec); ret = check_fec (dec, &fec); gst_rtp_buffer_unmap (&rtp); return ret; } static GstFlowReturn store_media_item (GstRTPST_2022_1_FecDec * dec, GstRTPBuffer * rtp, Item * item) { GstFlowReturn ret = GST_FLOW_OK; Item *fec_item; guint16 seq; seq = gst_rtp_buffer_get_seq (rtp); g_sequence_insert_sorted (dec->packets, item, (GCompareDataFunc) cmp_items, NULL); if ((fec_item = get_row_fec (dec, seq))) { ret = check_fec_item (dec, fec_item); if (ret == GST_FLOW_CUSTOM_SUCCESS) ret = GST_FLOW_OK; } if (ret == GST_FLOW_OK && (fec_item = get_column_fec (dec, seq))) { ret = check_fec_item (dec, fec_item); if (ret == GST_FLOW_CUSTOM_SUCCESS) ret = GST_FLOW_OK; } return ret; } static GstFlowReturn store_media (GstRTPST_2022_1_FecDec * dec, GstRTPBuffer * rtp, GstBuffer * buffer) { Item *item; guint16 seq; seq = gst_rtp_buffer_get_seq (rtp); item = g_malloc0 (sizeof (Item)); item->buffer = gst_buffer_ref (buffer); item->seq = seq; return store_media_item (dec, rtp, item); } static GstFlowReturn gst_rtpst_2022_1_fecdec_sink_chain_fec (GstPad * pad, GstObject * parent, GstBuffer * buffer) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (parent); Rtp2DFecHeader fec = { 0, }; guint payload_len; guint8 *payload; GstFlowReturn ret = GST_FLOW_OK; Item *item; GstRTPBuffer rtp = GST_RTP_BUFFER_INIT; GST_OBJECT_LOCK (dec); if (!gst_rtp_buffer_map (buffer, GST_MAP_READ, &rtp)) { GST_WARNING_OBJECT (pad, "Chained FEC buffer isn't valid RTP"); goto discard; } payload_len = gst_rtp_buffer_get_payload_len (&rtp); payload = gst_rtp_buffer_get_payload (&rtp); if (!parse_header (&rtp, &fec)) { GST_WARNING_OBJECT (pad, "Failed to parse FEC header (payload len: %d)", payload_len); GST_MEMDUMP_OBJECT (pad, "Invalid payload", payload, payload_len); goto discard; } GST_TRACE_OBJECT (pad, "Handling FEC buffer with SNBase / N / D / NA / offset %u / %u / %u / %u / %u", fec.seq, fec.N, fec.D, fec.NA, fec.offset); if (fec.D) { if (dec->l == G_MAXUINT) { dec->l = fec.NA; } else if (fec.NA != dec->l) { GST_WARNING_OBJECT (dec, "2D FEC dimensionality cannot change"); goto discard; } if (fec.offset != 1) { GST_WARNING_OBJECT (pad, "offset must be 1 for row FEC packets"); goto discard; } } else { if (dec->d == G_MAXUINT) { dec->d = fec.NA; } else if (fec.NA != dec->d) { GST_WARNING_OBJECT (dec, "2D FEC dimensionality cannot change"); goto discard; } if (dec->l == G_MAXUINT) { dec->l = fec.offset; } else if (fec.offset != dec->l) { GST_WARNING_OBJECT (dec, "2D FEC dimensionality cannot change"); goto discard; } } dec->max_fec_arrival_time[fec.D] = GST_BUFFER_DTS_OR_PTS (buffer); trim_fec_items (dec, fec.D); ret = check_fec (dec, &fec); if (ret == GST_FLOW_CUSTOM_SUCCESS) { item = g_malloc0 (sizeof (Item)); item->buffer = buffer; item->seq = fec.seq; if (!fec.D) { guint i; guint16 seq; for (i = 0; i < dec->d; i++) { seq = fec.seq + i * dec->l; g_hash_table_insert (dec->column_fec_packets, GUINT_TO_POINTER (seq), item); } } g_sequence_insert_sorted (dec->fec_packets[fec.D], item, (GCompareDataFunc) cmp_items, NULL); ret = GST_FLOW_OK; } else { goto discard; } gst_rtp_buffer_unmap (&rtp); done: GST_OBJECT_UNLOCK (dec); return ret; discard: if (rtp.buffer != NULL) gst_rtp_buffer_unmap (&rtp); gst_buffer_unref (buffer); goto done; } static GstFlowReturn gst_rtpst_2022_1_fecdec_sink_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (parent); GstFlowReturn ret = GST_FLOW_OK; GstRTPBuffer rtp = GST_RTP_BUFFER_INIT; if (!gst_rtp_buffer_map (buffer, GST_MAP_READ, &rtp)) { GST_WARNING_OBJECT (pad, "Chained buffer isn't valid RTP"); goto error; } GST_OBJECT_LOCK (dec); dec->max_arrival_time = MAX (dec->max_arrival_time, GST_BUFFER_DTS_OR_PTS (buffer)); trim_items (dec); ret = store_media (dec, &rtp, buffer); GST_OBJECT_UNLOCK (dec); gst_rtp_buffer_unmap (&rtp); if (ret == GST_FLOW_OK) ret = gst_pad_push (dec->srcpad, buffer); done: return ret; error: gst_buffer_unref (buffer); goto done; } static gboolean gst_rtpst_2022_1_fecdec_src_event (GstPad * pad, GstObject * parent, GstEvent * event) { gboolean handled = FALSE; gboolean ret = TRUE; if (!handled) { gst_pad_event_default (pad, parent, event); } return ret; } /* Takes the object lock */ static void gst_rtpst_2022_1_fecdec_reset (GstRTPST_2022_1_FecDec * dec, gboolean allocate) { guint i; GST_OBJECT_LOCK (dec); if (dec->packets) { g_sequence_free (dec->packets); dec->packets = NULL; } if (dec->column_fec_packets) { g_hash_table_unref (dec->column_fec_packets); dec->column_fec_packets = NULL; } if (allocate) { dec->packets = g_sequence_new ((GDestroyNotify) free_item); dec->column_fec_packets = g_hash_table_new (g_direct_hash, g_direct_equal); } for (i = 0; i < 2; i++) { if (dec->fec_packets[i]) { g_sequence_free (dec->fec_packets[i]); dec->fec_packets[i] = NULL; } if (allocate) dec->fec_packets[i] = g_sequence_new ((GDestroyNotify) free_item); } dec->d = G_MAXUINT; dec->l = G_MAXUINT; GST_OBJECT_UNLOCK (dec); } static GstStateChangeReturn gst_rtpst_2022_1_fecdec_change_state (GstElement * element, GstStateChange transition) { GstStateChangeReturn ret; GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (element); switch (transition) { case GST_STATE_CHANGE_READY_TO_PAUSED: gst_rtpst_2022_1_fecdec_reset (dec, TRUE); break; case GST_STATE_CHANGE_PAUSED_TO_READY: gst_rtpst_2022_1_fecdec_reset (dec, FALSE); break; default: break; } ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition); return ret; } static void gst_rtpst_2022_1_fecdec_finalize (GObject * object) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (object); gst_rtpst_2022_1_fecdec_reset (dec, FALSE); G_OBJECT_CLASS (parent_class)->finalize (object); } static void gst_rtpst_2022_1_fecdec_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (object); switch (prop_id) { case PROP_SIZE_TIME: dec->size_time = g_value_get_uint64 (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_rtpst_2022_1_fecdec_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (object); switch (prop_id) { case PROP_SIZE_TIME: g_value_set_uint64 (value, dec->size_time); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static gboolean gst_2d_fec_sink_event (GstPad * pad, GstObject * parent, GstEvent * event) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (parent); gboolean ret; if (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP) gst_rtpst_2022_1_fecdec_reset (dec, TRUE); ret = gst_pad_event_default (pad, parent, event); return ret; } static GstIterator * gst_rtpst_2022_1_fecdec_iterate_linked_pads (GstPad * pad, GstObject * parent) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (parent); GstPad *otherpad = NULL; GstIterator *it = NULL; GValue val = { 0, }; if (pad == dec->srcpad) otherpad = dec->sinkpad; else if (pad == dec->sinkpad) otherpad = dec->srcpad; if (otherpad) { g_value_init (&val, GST_TYPE_PAD); g_value_set_object (&val, otherpad); it = gst_iterator_new_single (GST_TYPE_PAD, &val); g_value_unset (&val); } return it; } static GstPad * gst_rtpst_2022_1_fecdec_request_new_pad (GstElement * element, GstPadTemplate * templ, const gchar * name, const GstCaps * caps) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (element); GstPad *sinkpad = NULL; GST_DEBUG_OBJECT (element, "requesting pad"); if (g_list_length (dec->fec_sinkpads) > 1) { GST_ERROR_OBJECT (dec, "not accepting more than two fec streams"); goto done; } sinkpad = gst_pad_new_from_template (templ, name); gst_pad_set_chain_function (sinkpad, gst_rtpst_2022_1_fecdec_sink_chain_fec); gst_element_add_pad (GST_ELEMENT (dec), sinkpad); gst_pad_set_iterate_internal_links_function (sinkpad, GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_iterate_linked_pads)); gst_pad_set_active (sinkpad, TRUE); GST_DEBUG_OBJECT (element, "requested pad %s:%s", GST_DEBUG_PAD_NAME (sinkpad)); done: return sinkpad; } static void gst_rtpst_2022_1_fecdec_release_pad (GstElement * element, GstPad * pad) { GstRTPST_2022_1_FecDec *dec = GST_RTPST_2022_1_FECDEC_CAST (element); GST_DEBUG_OBJECT (element, "releasing pad %s:%s", GST_DEBUG_PAD_NAME (pad)); dec->fec_sinkpads = g_list_remove (dec->fec_sinkpads, pad); gst_pad_set_active (pad, FALSE); gst_element_remove_pad (GST_ELEMENT_CAST (dec), pad); } static void gst_rtpst_2022_1_fecdec_class_init (GstRTPST_2022_1_FecDecClass * klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass); gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_set_property); gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_get_property); gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_finalize); g_object_class_install_property (gobject_class, PROP_SIZE_TIME, g_param_spec_uint64 ("size-time", "Storage size (in ns)", "The amount of data to store (in ns, 0-disable)", 0, G_MAXUINT64, DEFAULT_SIZE_TIME, G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS)); gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_change_state); gstelement_class->request_new_pad = GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_request_new_pad); gstelement_class->release_pad = GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_release_pad); gst_element_class_set_static_metadata (gstelement_class, "SMPTE 2022-1 FEC decoder", "SMPTE 2022-1 FEC decoding", "performs FEC as described by SMPTE 2022-1", "Mathieu Duponchelle "); gst_element_class_add_static_pad_template (gstelement_class, &sink_template); gst_element_class_add_static_pad_template (gstelement_class, &fec_sink_template); gst_element_class_add_static_pad_template (gstelement_class, &src_template); GST_DEBUG_CATEGORY_INIT (gst_rtpst_2022_1_fecdec_debug, "rtpst2022-1-fecdec", 0, "SMPTE 2022-1 FEC decoder element"); } static void gst_rtpst_2022_1_fecdec_init (GstRTPST_2022_1_FecDec * dec) { dec->srcpad = gst_pad_new_from_static_template (&src_template, "src"); GST_PAD_SET_PROXY_CAPS (dec->srcpad); gst_pad_use_fixed_caps (dec->srcpad); gst_pad_set_event_function (dec->srcpad, GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_src_event)); gst_pad_set_iterate_internal_links_function (dec->srcpad, GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_iterate_linked_pads)); gst_element_add_pad (GST_ELEMENT (dec), dec->srcpad); dec->sinkpad = gst_pad_new_from_static_template (&sink_template, "sink"); GST_PAD_SET_PROXY_CAPS (dec->sinkpad); gst_pad_set_chain_function (dec->sinkpad, gst_rtpst_2022_1_fecdec_sink_chain); gst_pad_set_event_function (dec->sinkpad, GST_DEBUG_FUNCPTR (gst_2d_fec_sink_event)); gst_pad_set_iterate_internal_links_function (dec->sinkpad, GST_DEBUG_FUNCPTR (gst_rtpst_2022_1_fecdec_iterate_linked_pads)); gst_element_add_pad (GST_ELEMENT (dec), dec->sinkpad); dec->d = G_MAXUINT; dec->l = G_MAXUINT; }