/* * mpegtspacketizer.c - * Copyright (C) 2007, 2008 Alessandro Decina, Zaheer Merali * * Authors: * Zaheer Merali * Alessandro Decina * * 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. */ #include #include /* Skew calculation pameters */ #define MAX_TIME (2 * GST_SECOND) /* maximal PCR time */ #define PCR_MAX_VALUE (((((guint64)1)<<33) * 300) + 298) #define PCR_GST_MAX_VALUE (PCR_MAX_VALUE * GST_MSECOND / (27000)) #define PTS_DTS_MAX_VALUE (((guint64)1) << 33) #include "mpegtspacketizer.h" #include "gstmpegdesc.h" GST_DEBUG_CATEGORY_STATIC (mpegts_packetizer_debug); #define GST_CAT_DEFAULT mpegts_packetizer_debug #define MPEGTS_PACKETIZER_GET_PRIVATE(obj) \ (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_MPEGTS_PACKETIZER, MpegTSPacketizerPrivate)) static void _init_local (void); G_DEFINE_TYPE_EXTENDED (MpegTSPacketizer2, mpegts_packetizer, G_TYPE_OBJECT, 0, _init_local ()); /* Maximum number of MpegTSPcr * 256 should be sufficient for most multiplexes */ #define MAX_PCR_OBS_CHANNELS 256 typedef struct _MpegTSPCR { guint16 pid; /* Following variables are only active/used when * calculate_skew is TRUE */ GstClockTime base_time; GstClockTime base_pcrtime; GstClockTime prev_out_time; GstClockTime prev_in_time; GstClockTime last_pcrtime; gint64 window[MAX_WINDOW]; guint window_pos; guint window_size; gboolean window_filling; gint64 window_min; gint64 skew; gint64 prev_send_diff; /* Offset to apply to PCR to handle wraparounds */ guint64 pcroffset; /* Used for bitrate calculation */ /* FIXME : Replace this later on with a balanced tree or sequence */ guint64 first_offset; guint64 first_pcr; GstClockTime first_pcr_ts; guint64 last_offset; guint64 last_pcr; GstClockTime last_pcr_ts; } MpegTSPCR; struct _MpegTSPacketizerPrivate { /* Shortcuts for adapter usage */ guint available; guint8 *mapped; guint offset; guint mapped_size; /* Reference offset */ guint64 refoffset; guint nb_seen_offsets; /* Last inputted timestamp */ GstClockTime last_in_time; /* offset to observations table */ guint8 pcrtablelut[0x2000]; MpegTSPCR *observations[MAX_PCR_OBS_CHANNELS]; guint8 lastobsid; }; static void mpegts_packetizer_dispose (GObject * object); static void mpegts_packetizer_finalize (GObject * object); static GstClockTime calculate_skew (MpegTSPCR * pcr, guint64 pcrtime, GstClockTime time); static void record_pcr (MpegTSPacketizer2 * packetizer, MpegTSPCR * pcrtable, guint64 pcr, guint64 offset); #define CONTINUITY_UNSET 255 #define VERSION_NUMBER_UNSET 255 #define TABLE_ID_UNSET 0xFF #define PACKET_SYNC_BYTE 0x47 static inline MpegTSPCR * get_pcr_table (MpegTSPacketizer2 * packetizer, guint16 pid) { MpegTSPacketizerPrivate *priv = packetizer->priv; MpegTSPCR *res; res = priv->observations[priv->pcrtablelut[pid]]; if (G_UNLIKELY (res == NULL)) { /* If we don't have a PCR table for the requested PID, create one .. */ res = g_new0 (MpegTSPCR, 1); /* Add it to the last table position */ priv->observations[priv->lastobsid] = res; /* Update the pcrtablelut */ priv->pcrtablelut[pid] = priv->lastobsid; /* And increment the last know slot */ priv->lastobsid++; /* Finally set the default values */ res->pid = pid; res->first_offset = -1; res->first_pcr = -1; res->first_pcr_ts = GST_CLOCK_TIME_NONE; res->last_offset = -1; res->last_pcr = -1; res->last_pcr_ts = GST_CLOCK_TIME_NONE; res->base_time = GST_CLOCK_TIME_NONE; res->base_pcrtime = GST_CLOCK_TIME_NONE; res->last_pcrtime = GST_CLOCK_TIME_NONE; res->window_pos = 0; res->window_filling = TRUE; res->window_min = 0; res->skew = 0; res->prev_send_diff = GST_CLOCK_TIME_NONE; res->prev_out_time = GST_CLOCK_TIME_NONE; res->pcroffset = 0; } return res; } static void flush_observations (MpegTSPacketizer2 * packetizer) { MpegTSPacketizerPrivate *priv = packetizer->priv; gint i; for (i = 0; i < priv->lastobsid; i++) { g_free (priv->observations[i]); priv->observations[i] = NULL; } memset (priv->pcrtablelut, 0xff, 0x2000); priv->lastobsid = 0; } static inline MpegTSPacketizerStreamSubtable * find_subtable (GSList * subtables, guint8 table_id, guint16 subtable_extension) { GSList *tmp; /* FIXME: Make this an array ! */ for (tmp = subtables; tmp; tmp = tmp->next) { MpegTSPacketizerStreamSubtable *sub = (MpegTSPacketizerStreamSubtable *) tmp->data; if (sub->table_id == table_id && sub->subtable_extension == subtable_extension) return sub; } return FALSE; } static gboolean seen_section_before (MpegTSPacketizerStream * stream, guint8 table_id, guint16 subtable_extension, guint8 version_number, guint8 section_number, guint8 last_section_number) { MpegTSPacketizerStreamSubtable *subtable; /* Check if we've seen this table_id/subtable_extension first */ subtable = find_subtable (stream->subtables, table_id, subtable_extension); if (!subtable) { GST_DEBUG ("Haven't seen subtale"); return FALSE; } /* If we have, check it has the same version_number */ if (subtable->version_number != version_number) { GST_DEBUG ("Different version number"); return FALSE; } /* Did the number of sections change ? */ if (subtable->last_section_number != last_section_number) { GST_DEBUG ("Different last_section_number"); return FALSE; } /* Finally return whether we saw that section or not */ return MPEGTS_BIT_IS_SET (subtable->seen_section, section_number); } static MpegTSPacketizerStreamSubtable * mpegts_packetizer_stream_subtable_new (guint8 table_id, guint16 subtable_extension, guint8 last_section_number) { MpegTSPacketizerStreamSubtable *subtable; subtable = g_new0 (MpegTSPacketizerStreamSubtable, 1); subtable->version_number = VERSION_NUMBER_UNSET; subtable->table_id = table_id; subtable->subtable_extension = subtable_extension; subtable->last_section_number = last_section_number; return subtable; } static MpegTSPacketizerStream * mpegts_packetizer_stream_new (guint16 pid) { MpegTSPacketizerStream *stream; stream = (MpegTSPacketizerStream *) g_new0 (MpegTSPacketizerStream, 1); stream->continuity_counter = CONTINUITY_UNSET; stream->subtables = NULL; stream->table_id = TABLE_ID_UNSET; stream->pid = pid; return stream; } static void mpegts_packetizer_clear_section (MpegTSPacketizerStream * stream) { stream->continuity_counter = CONTINUITY_UNSET; stream->section_length = 0; stream->section_offset = 0; stream->table_id = TABLE_ID_UNSET; if (stream->section_data) g_free (stream->section_data); stream->section_data = NULL; } static void mpegts_packetizer_stream_subtable_free (MpegTSPacketizerStreamSubtable * subtable) { g_free (subtable); } static void mpegts_packetizer_stream_free (MpegTSPacketizerStream * stream) { mpegts_packetizer_clear_section (stream); if (stream->section_data) g_free (stream->section_data); g_slist_foreach (stream->subtables, (GFunc) mpegts_packetizer_stream_subtable_free, NULL); g_slist_free (stream->subtables); g_free (stream); } static void mpegts_packetizer_class_init (MpegTSPacketizer2Class * klass) { GObjectClass *gobject_class; g_type_class_add_private (klass, sizeof (MpegTSPacketizerPrivate)); gobject_class = G_OBJECT_CLASS (klass); gobject_class->dispose = mpegts_packetizer_dispose; gobject_class->finalize = mpegts_packetizer_finalize; } static void mpegts_packetizer_init (MpegTSPacketizer2 * packetizer) { MpegTSPacketizerPrivate *priv; priv = packetizer->priv = MPEGTS_PACKETIZER_GET_PRIVATE (packetizer); packetizer->adapter = gst_adapter_new (); packetizer->offset = 0; packetizer->empty = TRUE; packetizer->streams = g_new0 (MpegTSPacketizerStream *, 8192); packetizer->packet_size = 0; packetizer->calculate_skew = FALSE; packetizer->calculate_offset = FALSE; priv->available = 0; priv->mapped = NULL; priv->mapped_size = 0; priv->offset = 0; memset (priv->pcrtablelut, 0xff, 0x2000); memset (priv->observations, 0x0, sizeof (priv->observations)); priv->lastobsid = 0; priv->nb_seen_offsets = 0; priv->refoffset = -1; priv->last_in_time = GST_CLOCK_TIME_NONE; } static void mpegts_packetizer_dispose (GObject * object) { MpegTSPacketizer2 *packetizer = GST_MPEGTS_PACKETIZER (object); if (!packetizer->disposed) { if (packetizer->packet_size) packetizer->packet_size = 0; if (packetizer->streams) { int i; for (i = 0; i < 8192; i++) { if (packetizer->streams[i]) mpegts_packetizer_stream_free (packetizer->streams[i]); } g_free (packetizer->streams); } gst_adapter_clear (packetizer->adapter); g_object_unref (packetizer->adapter); packetizer->disposed = TRUE; packetizer->offset = 0; packetizer->empty = TRUE; flush_observations (packetizer); } if (G_OBJECT_CLASS (mpegts_packetizer_parent_class)->dispose) G_OBJECT_CLASS (mpegts_packetizer_parent_class)->dispose (object); } static void mpegts_packetizer_finalize (GObject * object) { if (G_OBJECT_CLASS (mpegts_packetizer_parent_class)->finalize) G_OBJECT_CLASS (mpegts_packetizer_parent_class)->finalize (object); } static inline guint64 mpegts_packetizer_compute_pcr (const guint8 * data) { guint32 pcr1; guint16 pcr2; guint64 pcr, pcr_ext; pcr1 = GST_READ_UINT32_BE (data); pcr2 = GST_READ_UINT16_BE (data + 4); pcr = ((guint64) pcr1) << 1; pcr |= (pcr2 & 0x8000) >> 15; pcr_ext = (pcr2 & 0x01ff); return pcr * 300 + pcr_ext % 300; } static gboolean mpegts_packetizer_parse_adaptation_field_control (MpegTSPacketizer2 * packetizer, MpegTSPacketizerPacket * packet) { guint8 length, afcflags; guint8 *data; length = *packet->data++; /* an adaptation field with length 0 is valid and * can be used to insert a single stuffing byte */ if (!length) { packet->afc_flags = 0; return TRUE; } if (FLAGS_HAS_AFC (packet->scram_afc_cc)) { /* no payload, adaptation field of 183 bytes */ if (length != 183) { GST_DEBUG ("PID %d afc == 0x%02x and length %d != 183", packet->pid, packet->scram_afc_cc & 0x30, length); } } else if (length > 182) { GST_DEBUG ("PID %d afc == 0x%02x and length %d > 182", packet->pid, packet->scram_afc_cc & 0x30, length); } if (packet->data + length > packet->data_end) { GST_DEBUG ("PID %d afc length %d overflows the buffer current %d max %d", packet->pid, length, (gint) (packet->data - packet->data_start), (gint) (packet->data_end - packet->data_start)); return FALSE; } data = packet->data; packet->data += length; afcflags = packet->afc_flags = *data++; GST_DEBUG ("flags: %s%s%s%s%s%s%s%s%s", afcflags & 0x80 ? "discontinuity " : "", afcflags & 0x40 ? "random_access " : "", afcflags & 0x20 ? "elementary_stream_priority " : "", afcflags & 0x10 ? "PCR " : "", afcflags & 0x08 ? "OPCR " : "", afcflags & 0x04 ? "splicing_point " : "", afcflags & 0x02 ? "transport_private_data " : "", afcflags & 0x01 ? "extension " : "", afcflags == 0x00 ? "" : ""); /* PCR */ if (afcflags & MPEGTS_AFC_PCR_FLAG) { MpegTSPCR *pcrtable = NULL; packet->pcr = mpegts_packetizer_compute_pcr (data); data += 6; GST_DEBUG ("pcr 0x%04x %" G_GUINT64_FORMAT " (%" GST_TIME_FORMAT ") offset:%" G_GUINT64_FORMAT, packet->pid, packet->pcr, GST_TIME_ARGS (PCRTIME_TO_GSTTIME (packet->pcr)), packet->offset); if (packetizer->calculate_skew && GST_CLOCK_TIME_IS_VALID (packetizer->priv->last_in_time)) { pcrtable = get_pcr_table (packetizer, packet->pid); calculate_skew (pcrtable, packet->pcr, packetizer->priv->last_in_time); } if (packetizer->calculate_offset) { if (!pcrtable) pcrtable = get_pcr_table (packetizer, packet->pid); record_pcr (packetizer, pcrtable, packet->pcr, packet->offset); } } #ifndef GST_DISABLE_GST_DEBUG /* OPCR */ if (afcflags & MPEGTS_AFC_OPCR_FLAG) { /* Note: We don't use/need opcr for the time being */ guint64 opcr = mpegts_packetizer_compute_pcr (data); data += 6; GST_DEBUG ("opcr %" G_GUINT64_FORMAT " (%" GST_TIME_FORMAT ")", opcr, GST_TIME_ARGS (PCRTIME_TO_GSTTIME (opcr))); } if (afcflags & MPEGTS_AFC_SPLICING_POINT_FLAG) { GST_DEBUG ("splice_countdown: %u", *data++); } if (afcflags & MPEGTS_AFC_TRANSPORT_PRIVATE_DATA_FLAG) { guint8 len = *data++; GST_MEMDUMP ("private data", data, len); data += len; } if (afcflags & MPEGTS_AFC_EXTENSION_FLAG) { guint8 extlen = *data++; guint8 flags = *data++; GST_DEBUG ("extension size:%d flags : %s%s%s", extlen, flags & 0x80 ? "ltw " : "", flags & 0x40 ? "piecewise_rate " : "", flags & 0x20 ? "seamless_splice " : ""); if (flags & 0x80) { GST_DEBUG ("legal time window: valid_flag:%d offset:%d", *data >> 7, GST_READ_UINT16_BE (data) & 0x7fff); data += 2; } } #endif return TRUE; } static MpegTSPacketizerPacketReturn mpegts_packetizer_parse_packet (MpegTSPacketizer2 * packetizer, MpegTSPacketizerPacket * packet) { guint8 *data; guint8 tmp; data = packet->data_start; data += 1; tmp = *data; /* transport_error_indicator 1 */ if (G_UNLIKELY (tmp & 0x80)) return PACKET_BAD; /* payload_unit_start_indicator 1 */ packet->payload_unit_start_indicator = tmp & 0x40; /* transport_priority 1 */ /* PID 13 */ packet->pid = GST_READ_UINT16_BE (data) & 0x1FFF; data += 2; packet->scram_afc_cc = tmp = *data++; /* transport_scrambling_control 2 */ if (G_UNLIKELY (tmp & 0xc0)) return PACKET_BAD; packet->data = data; if (FLAGS_HAS_AFC (tmp)) if (!mpegts_packetizer_parse_adaptation_field_control (packetizer, packet)) return FALSE; if (FLAGS_HAS_PAYLOAD (tmp)) packet->payload = packet->data; else packet->payload = NULL; return PACKET_OK; } static GstMpegTsSection * mpegts_packetizer_parse_section_header (MpegTSPacketizer2 * packetizer, MpegTSPacketizerStream * stream) { MpegTSPacketizerStreamSubtable *subtable; GstMpegTsSection *res; subtable = find_subtable (stream->subtables, stream->table_id, stream->subtable_extension); if (subtable) { GST_DEBUG ("Found previous subtable_extension:0x%04x", stream->subtable_extension); if (G_UNLIKELY (stream->version_number != subtable->version_number)) { /* If the version number changed, reset the subtable */ subtable->version_number = stream->version_number; subtable->last_section_number = stream->last_section_number; memset (subtable->seen_section, 0, 32); } } else { GST_DEBUG ("Appending new subtable_extension: 0x%04x", stream->subtable_extension); subtable = mpegts_packetizer_stream_subtable_new (stream->table_id, stream->subtable_extension, stream->last_section_number); subtable->version_number = stream->version_number; stream->subtables = g_slist_prepend (stream->subtables, subtable); } GST_MEMDUMP ("Full section data", stream->section_data, stream->section_length); /* TODO ? : Replace this by an efficient version (where we provide all * pre-parsed header data) */ res = gst_mpegts_section_new (stream->pid, stream->section_data, stream->section_length); stream->section_data = NULL; mpegts_packetizer_clear_section (stream); if (res) { /* NOTE : Due to the new mpegts-si system, There is a insanely low probability * that we might have gotten a section that was corrupted (i.e. wrong crc) * and that we consider it as seen. * * The reason why we consider this as acceptable is because all the previous * checks were already done: * * transport layer checks (DVB) * * 0x47 validation * * continuity counter validation * * subtable validation * * section_number validation * * section_length validation * * The probability of this happening vs the overhead of doing CRC checks * on all sections (including those we would not use) is just not worth it. * */ MPEGTS_BIT_SET (subtable->seen_section, stream->section_number); res->offset = stream->offset; } return res; } void mpegts_packetizer_clear (MpegTSPacketizer2 * packetizer) { if (packetizer->packet_size) packetizer->packet_size = 0; if (packetizer->streams) { int i; for (i = 0; i < 8192; i++) { if (packetizer->streams[i]) { mpegts_packetizer_stream_free (packetizer->streams[i]); } } memset (packetizer->streams, 0, 8192 * sizeof (MpegTSPacketizerStream *)); } gst_adapter_clear (packetizer->adapter); packetizer->offset = 0; packetizer->empty = TRUE; packetizer->priv->available = 0; packetizer->priv->mapped = NULL; packetizer->priv->mapped_size = 0; packetizer->priv->offset = 0; packetizer->priv->last_in_time = GST_CLOCK_TIME_NONE; } void mpegts_packetizer_flush (MpegTSPacketizer2 * packetizer, gboolean hard) { GST_DEBUG ("Flushing"); if (packetizer->streams) { int i; for (i = 0; i < 8192; i++) { if (packetizer->streams[i]) { mpegts_packetizer_clear_section (packetizer->streams[i]); } } } gst_adapter_clear (packetizer->adapter); packetizer->offset = 0; packetizer->empty = TRUE; packetizer->priv->available = 0; packetizer->priv->mapped = NULL; packetizer->priv->offset = 0; packetizer->priv->mapped_size = 0; packetizer->priv->last_in_time = GST_CLOCK_TIME_NONE; if (hard) { /* For pull mode seeks in tsdemux the observation must be preserved */ flush_observations (packetizer); } } void mpegts_packetizer_remove_stream (MpegTSPacketizer2 * packetizer, gint16 pid) { MpegTSPacketizerStream *stream = packetizer->streams[pid]; if (stream) { GST_INFO ("Removing stream for PID %d", pid); mpegts_packetizer_stream_free (stream); packetizer->streams[pid] = NULL; } } MpegTSPacketizer2 * mpegts_packetizer_new (void) { MpegTSPacketizer2 *packetizer; packetizer = GST_MPEGTS_PACKETIZER (g_object_new (GST_TYPE_MPEGTS_PACKETIZER, NULL)); return packetizer; } void mpegts_packetizer_push (MpegTSPacketizer2 * packetizer, GstBuffer * buffer) { if (G_UNLIKELY (packetizer->empty)) { packetizer->empty = FALSE; packetizer->offset = GST_BUFFER_OFFSET (buffer); } GST_DEBUG ("Pushing %" G_GSIZE_FORMAT " byte from offset %" G_GUINT64_FORMAT, gst_buffer_get_size (buffer), GST_BUFFER_OFFSET (buffer)); gst_adapter_push (packetizer->adapter, buffer); packetizer->priv->available += gst_buffer_get_size (buffer); /* If buffer timestamp is valid, store it */ if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buffer))) packetizer->priv->last_in_time = GST_BUFFER_TIMESTAMP (buffer); } static gboolean mpegts_try_discover_packet_size (MpegTSPacketizer2 * packetizer) { guint8 *dest; int i, pos = -1, j; static const guint psizes[] = { MPEGTS_NORMAL_PACKETSIZE, MPEGTS_M2TS_PACKETSIZE, MPEGTS_DVB_ASI_PACKETSIZE, MPEGTS_ATSC_PACKETSIZE }; dest = g_malloc (MPEGTS_MAX_PACKETSIZE * 4); /* wait for 3 sync bytes */ while (packetizer->priv->available >= MPEGTS_MAX_PACKETSIZE * 4) { /* check for sync bytes */ gst_adapter_copy (packetizer->adapter, dest, 0, MPEGTS_MAX_PACKETSIZE * 4); /* find first sync byte */ pos = -1; for (i = 0; i < MPEGTS_MAX_PACKETSIZE; i++) { if (dest[i] == PACKET_SYNC_BYTE) { for (j = 0; j < 4; j++) { guint packetsize = psizes[j]; /* check each of the packet size possibilities in turn */ if (dest[i] == PACKET_SYNC_BYTE && dest[i + packetsize] == PACKET_SYNC_BYTE && dest[i + packetsize * 2] == PACKET_SYNC_BYTE && dest[i + packetsize * 3] == PACKET_SYNC_BYTE) { packetizer->packet_size = packetsize; if (packetsize == MPEGTS_M2TS_PACKETSIZE) pos = i - 4; else pos = i; break; } } break; } } if (packetizer->packet_size) break; /* Skip MPEGTS_MAX_PACKETSIZE */ gst_adapter_flush (packetizer->adapter, MPEGTS_MAX_PACKETSIZE); packetizer->priv->available -= MPEGTS_MAX_PACKETSIZE; packetizer->offset += MPEGTS_MAX_PACKETSIZE; } g_free (dest); if (packetizer->packet_size) { GST_DEBUG ("have packetsize detected: %d of %u bytes", packetizer->packet_size, packetizer->packet_size); /* flush to sync byte */ if (pos > 0) { GST_DEBUG ("Flushing out %d bytes", pos); gst_adapter_flush (packetizer->adapter, pos); packetizer->offset += pos; packetizer->priv->available -= MPEGTS_MAX_PACKETSIZE; } } else { /* drop invalid data and move to the next possible packets */ GST_DEBUG ("Could not determine packet size"); } return packetizer->packet_size; } gboolean mpegts_packetizer_has_packets (MpegTSPacketizer2 * packetizer) { if (G_UNLIKELY (!packetizer->packet_size)) { if (!mpegts_try_discover_packet_size (packetizer)) return FALSE; } return packetizer->priv->available >= packetizer->packet_size; } MpegTSPacketizerPacketReturn mpegts_packetizer_next_packet (MpegTSPacketizer2 * packetizer, MpegTSPacketizerPacket * packet) { MpegTSPacketizerPrivate *priv = packetizer->priv; guint skip; guint sync_offset; guint packet_size; packet_size = packetizer->packet_size; if (G_UNLIKELY (!packet_size)) { if (!mpegts_try_discover_packet_size (packetizer)) return PACKET_NEED_MORE; packet_size = packetizer->packet_size; } while (priv->available >= packet_size) { if (priv->mapped == NULL) { priv->mapped_size = priv->available; priv->mapped = (guint8 *) gst_adapter_map (packetizer->adapter, priv->mapped_size); priv->offset = 0; } /* M2TS packets don't start with the sync byte, all other variants do */ sync_offset = priv->offset; if (packet_size == MPEGTS_M2TS_PACKETSIZE) sync_offset += 4; /* Check sync byte */ if (G_LIKELY (priv->mapped[sync_offset] == 0x47)) { /* ALL mpeg-ts variants contain 188 bytes of data. Those with bigger * packet sizes contain either extra data (timesync, FEC, ..) either * before or after the data */ packet->data_start = priv->mapped + sync_offset; packet->data_end = packet->data_start + 188; packet->offset = packetizer->offset; GST_LOG ("offset %" G_GUINT64_FORMAT, packet->offset); packetizer->offset += packet_size; GST_MEMDUMP ("data_start", packet->data_start, 16); goto got_valid_packet; } GST_LOG ("Lost sync %d", packet_size); /* Find the 0x47 in the buffer (and require at least 2 checks) */ for (; sync_offset + 2 * packet_size < priv->mapped_size; sync_offset++) if (priv->mapped[sync_offset] == 0x47 && priv->mapped[sync_offset + packet_size] == 0x47 && priv->mapped[sync_offset + 2 * packet_size] == 0x47) break; /* Pop out the remaining data... */ skip = sync_offset - priv->offset; if (packet_size == MPEGTS_M2TS_PACKETSIZE) skip -= 4; priv->available -= skip; priv->offset += skip; packetizer->offset += skip; if (G_UNLIKELY (priv->available < packet_size)) { GST_DEBUG ("Flushing %d bytes out", priv->offset); gst_adapter_flush (packetizer->adapter, priv->offset); priv->mapped = NULL; } } return PACKET_NEED_MORE; got_valid_packet: return mpegts_packetizer_parse_packet (packetizer, packet); } MpegTSPacketizerPacketReturn mpegts_packetizer_process_next_packet (MpegTSPacketizer2 * packetizer) { MpegTSPacketizerPacket packet; MpegTSPacketizerPacketReturn ret; ret = mpegts_packetizer_next_packet (packetizer, &packet); if (ret != PACKET_NEED_MORE) { packetizer->priv->offset += packetizer->packet_size; packetizer->priv->available -= packetizer->packet_size; if (G_UNLIKELY (packetizer->priv->available < packetizer->packet_size)) { gst_adapter_flush (packetizer->adapter, packetizer->priv->offset); packetizer->priv->mapped = NULL; } } return ret; } void mpegts_packetizer_clear_packet (MpegTSPacketizer2 * packetizer, MpegTSPacketizerPacket * packet) { guint8 packet_size = packetizer->packet_size; MpegTSPacketizerPrivate *priv = packetizer->priv; priv->offset += packet_size; priv->available -= packet_size; if (G_UNLIKELY (priv->mapped && priv->available < packet_size)) { gst_adapter_flush (packetizer->adapter, priv->offset); priv->mapped = NULL; } } /* * Ideally it should just return a section if: * * The section is complete * * The section is valid (sanity checks for length for example) * * The section applies now (current_next_indicator) * * The section is an update or was never seen * * The section should be a new GstMpegTsSection: * * properly initialized * * With pid, table_id AND section_type set (move logic from mpegtsbase) * * With data copied into it (yes, minor overhead) * * In all other cases it should just return NULL * * If more than one section is available, the 'remaining' field will * be set to the beginning of a valid GList containing other sections. * */ GstMpegTsSection * mpegts_packetizer_push_section (MpegTSPacketizer2 * packetizer, MpegTSPacketizerPacket * packet, GList ** remaining) { GstMpegTsSection *section; GstMpegTsSection *res = NULL; MpegTSPacketizerStream *stream; gboolean long_packet; guint8 pointer = 0, table_id; guint16 subtable_extension = 0; gsize to_read; guint section_length; /* data points to the current read location * data_start points to the beginning of the data to accumulate */ guint8 *data, *data_start; guint8 packet_cc; GList *others = NULL; guint8 version_number, section_number, last_section_number; data = packet->data; packet_cc = FLAGS_CONTINUITY_COUNTER (packet->scram_afc_cc); /* Get our filter */ stream = packetizer->streams[packet->pid]; if (G_UNLIKELY (stream == NULL)) { if (!packet->payload_unit_start_indicator) { /* Early exit (we need to start with a section start) */ GST_DEBUG ("PID 0x%04x waiting for section start", packet->pid); goto out; } stream = mpegts_packetizer_stream_new (packet->pid); packetizer->streams[packet->pid] = stream; } GST_MEMDUMP ("Full packet data", packet->data, packet->data_end - packet->data); /* This function is split into several parts: * * Pre checks (packet-wide). Determines where we go next * accumulate_data: store data and check if section is complete * section_start: handle beginning of a section, if needed loop back to * accumulate_data * * The trigger that makes the loop stop and return is if: * 1) We do not have enough data for the current packet * 2) There is remaining data after a packet which is only made * of stuffing bytes (0xff). * * Pre-loop checks, related to the whole incoming packet: * * If there is a CC-discont: * If it is a PUSI, skip the pointer and handle section_start * If not a PUSI, reset and return nothing * If there is not a CC-discont: * If it is a PUSI * If pointer, accumulate that data and check for complete section * (loop) * If it is not a PUSI * Accumulate the expected data and check for complete section * (loop) * **/ if (packet->payload_unit_start_indicator) { pointer = *data++; /* If the pointer is zero, we're guaranteed to be able to handle it */ if (pointer == 0) { GST_LOG ("PID 0x%04x PUSI and pointer == 0, skipping straight to section_start parsing", packet->pid); goto section_start; } } if (stream->continuity_counter == CONTINUITY_UNSET || (stream->continuity_counter + 1) % 16 != packet_cc) { if (stream->continuity_counter != CONTINUITY_UNSET) GST_WARNING ("PID 0x%04x section discontinuity (%d vs %d)", packet->pid, stream->continuity_counter, packet_cc); mpegts_packetizer_clear_section (stream); /* If not a PUSI, not much we can do */ if (!packet->payload_unit_start_indicator) { GST_LOG ("PID 0x%04x continuity discont/unset and not PUSI, bailing out", packet->pid); goto out; } /* If PUSI, skip pointer data and carry on to section start */ data += pointer; pointer = 0; GST_LOG ("discont, but PUSI, skipped %d bytes and doing section start", pointer); goto section_start; } GST_LOG ("Accumulating data from beginning of packet"); data_start = data; accumulate_data: /* If not the beginning of a new section, accumulate what we have */ stream->continuity_counter = packet_cc; to_read = MIN (stream->section_length - stream->section_offset, packet->data_end - data_start); memcpy (stream->section_data + stream->section_offset, data_start, to_read); stream->section_offset += to_read; /* Point data to after the data we accumulated */ data = data_start + to_read; GST_DEBUG ("Appending data (need %d, have %d)", stream->section_length, stream->section_offset); /* Check if we have enough */ if (stream->section_offset < stream->section_length) { GST_DEBUG ("PID 0x%04x, section not complete (Got %d, need %d)", stream->pid, stream->section_offset, stream->section_length); goto out; } /* Small sanity check. We should have collected *exactly* the right amount */ if (G_UNLIKELY (stream->section_offset != stream->section_length)) GST_WARNING ("PID 0x%04x Accumulated too much data (%d vs %d) !", stream->pid, stream->section_offset, stream->section_length); GST_DEBUG ("PID 0x%04x Section complete", stream->pid); if ((section = mpegts_packetizer_parse_section_header (packetizer, stream))) { if (res) others = g_list_append (others, section); else res = section; } /* FIXME : We need at least 8 bytes with current algorithm :( * We might end up losing sections that start across two packets (srsl...) */ if (data > packet->data_end - 8 || *data == 0xff) { /* flush stuffing bytes and leave */ mpegts_packetizer_clear_section (stream); goto out; } /* We have more data to process ... */ GST_DEBUG ("PID 0x%04x, More section present in packet (remaining bytes:%" G_GSIZE_FORMAT ")", stream->pid, packet->data_end - data); section_start: GST_MEMDUMP ("section_start", data, packet->data_end - data); data_start = data; /* Beginning of a new section */ /* * section_syntax_indicator means that the header is of the following format: * * table_id (8bit) * * section_syntax_indicator (1bit) == 0 * * reserved/private fields (3bit) * * section_length (12bit) * * data (of size section_length) * * NO CRC ! */ long_packet = data[1] & 0x80; /* Fast path for short packets */ if (!long_packet) { /* We can create the section now (function will check for size) */ GST_DEBUG ("Short packet"); section_length = (GST_READ_UINT16_BE (data + 1) & 0xfff) + 3; /* Only do fast-path if we have enough byte */ if (section_length < packet->data_end - data) { if ((section = gst_mpegts_section_new (packet->pid, g_memdup (data, section_length), section_length))) { GST_DEBUG ("PID 0x%04x Short section complete !", packet->pid); section->offset = packet->offset; if (res) others = g_list_append (others, section); else res = section; } /* Advance reader and potentially read another section */ data += section_length; if (data < packet->data_end && *data != 0xff) goto section_start; /* If not, exit */ goto out; } /* We don't have enough bytes to do short section shortcut */ } /* Beginning of a new section, do as much pre-parsing as possible */ /* table_id : 8 bit */ table_id = *data++; /* section_syntax_indicator : 1 bit * other_fields (reserved) : 3 bit * section_length : 12 bit */ section_length = (GST_READ_UINT16_BE (data) & 0x0FFF) + 3; data += 2; if (long_packet) { /* subtable_extension (always present, we are in a long section) */ /* subtable extension : 16 bit */ subtable_extension = GST_READ_UINT16_BE (data); data += 2; /* reserved : 2 bit * version_number : 5 bit * current_next_indicator : 1 bit */ /* Bail out now if current_next_indicator == 0 */ if (G_UNLIKELY (!(*data & 0x01))) { GST_DEBUG ("PID 0x%04x table_id 0x%02x section does not apply (current_next_indicator == 0)", packet->pid, table_id); goto out; } version_number = *data++ >> 1 & 0x1f; /* section_number : 8 bit */ section_number = *data++; /* last_section_number : 8 bit */ last_section_number = *data++; } else { subtable_extension = 0; version_number = 0; section_number = 0; last_section_number = 0; } GST_DEBUG ("PID 0x%04x length:%d table_id:0x%02x subtable_extension:0x%04x version_number:%d section_number:%d(last:%d)", packet->pid, section_length, table_id, subtable_extension, version_number, section_number, last_section_number); to_read = MIN (section_length, packet->data_end - data_start); /* Check as early as possible whether we already saw this section * i.e. that we saw a subtable with: * * same subtable_extension (might be zero) * * same version_number * * same last_section_number * * same section_number was seen */ if (seen_section_before (stream, table_id, subtable_extension, version_number, section_number, last_section_number)) { GST_DEBUG ("PID 0x%04x Already processed table_id:0x%02x subtable_extension:0x%04x, version_number:%d, section_number:%d", packet->pid, table_id, subtable_extension, version_number, section_number); /* skip data and see if we have more sections after */ data = data_start + to_read; if (data == packet->data_end || *data == 0xff) goto out; goto section_start; } if (G_UNLIKELY (section_number > last_section_number)) { GST_WARNING ("PID 0x%04x corrupted packet (section_number:%d > last_section_number:%d)", packet->pid, section_number, last_section_number); goto out; } /* Copy over already parsed values */ stream->table_id = table_id; stream->section_length = section_length; stream->version_number = version_number; stream->subtable_extension = subtable_extension; stream->section_number = section_number; stream->last_section_number = last_section_number; stream->offset = packet->offset; /* Create enough room to store chunks of sections */ stream->section_data = g_malloc (stream->section_length); stream->section_offset = 0; /* Finally, accumulate and check if we parsed enough */ goto accumulate_data; out: packet->data = data; *remaining = others; GST_DEBUG ("result: %p", res); return res; } static void _init_local (void) { GST_DEBUG_CATEGORY_INIT (mpegts_packetizer_debug, "mpegtspacketizer", 0, "MPEG transport stream parser"); } static void mpegts_packetizer_resync (MpegTSPCR * pcr, GstClockTime time, GstClockTime gstpcrtime, gboolean reset_skew) { pcr->base_time = time; pcr->base_pcrtime = gstpcrtime; pcr->prev_out_time = GST_CLOCK_TIME_NONE; pcr->prev_send_diff = GST_CLOCK_TIME_NONE; if (reset_skew) { pcr->window_filling = TRUE; pcr->window_pos = 0; pcr->window_min = 0; pcr->window_size = 0; pcr->skew = 0; } } /* Code mostly copied from -good/gst/rtpmanager/rtpjitterbuffer.c */ /* For the clock skew we use a windowed low point averaging algorithm as can be * found in Fober, Orlarey and Letz, 2005, "Real Time Clock Skew Estimation * over Network Delays": * http://www.grame.fr/Ressources/pub/TR-050601.pdf * http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.102.1546 * * The idea is that the jitter is composed of: * * J = N + n * * N : a constant network delay. * n : random added noise. The noise is concentrated around 0 * * In the receiver we can track the elapsed time at the sender with: * * send_diff(i) = (Tsi - Ts0); * * Tsi : The time at the sender at packet i * Ts0 : The time at the sender at the first packet * * This is the difference between the RTP timestamp in the first received packet * and the current packet. * * At the receiver we have to deal with the jitter introduced by the network. * * recv_diff(i) = (Tri - Tr0) * * Tri : The time at the receiver at packet i * Tr0 : The time at the receiver at the first packet * * Both of these values contain a jitter Ji, a jitter for packet i, so we can * write: * * recv_diff(i) = (Cri + D + ni) - (Cr0 + D + n0)) * * Cri : The time of the clock at the receiver for packet i * D + ni : The jitter when receiving packet i * * We see that the network delay is irrelevant here as we can elliminate D: * * recv_diff(i) = (Cri + ni) - (Cr0 + n0)) * * The drift is now expressed as: * * Drift(i) = recv_diff(i) - send_diff(i); * * We now keep the W latest values of Drift and find the minimum (this is the * one with the lowest network jitter and thus the one which is least affected * by it). We average this lowest value to smooth out the resulting network skew. * * Both the window and the weighting used for averaging influence the accuracy * of the drift estimation. Finding the correct parameters turns out to be a * compromise between accuracy and inertia. * * We use a 2 second window or up to 512 data points, which is statistically big * enough to catch spikes (FIXME, detect spikes). * We also use a rather large weighting factor (125) to smoothly adapt. During * startup, when filling the window, we use a parabolic weighting factor, the * more the window is filled, the faster we move to the detected possible skew. * * Returns: @time adjusted with the clock skew. */ static GstClockTime calculate_skew (MpegTSPCR * pcr, guint64 pcrtime, GstClockTime time) { guint64 send_diff, recv_diff; gint64 delta; gint64 old; gint pos, i; GstClockTime gstpcrtime, out_time; #ifndef GST_DISABLE_GST_DEBUG guint64 slope; #endif gstpcrtime = PCRTIME_TO_GSTTIME (pcrtime) + pcr->pcroffset; /* first time, lock on to time and gstpcrtime */ if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (pcr->base_time))) { pcr->base_time = time; pcr->prev_out_time = GST_CLOCK_TIME_NONE; GST_DEBUG ("Taking new base time %" GST_TIME_FORMAT, GST_TIME_ARGS (time)); } if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (pcr->base_pcrtime))) { pcr->base_pcrtime = gstpcrtime; pcr->prev_send_diff = -1; GST_DEBUG ("Taking new base pcrtime %" GST_TIME_FORMAT, GST_TIME_ARGS (gstpcrtime)); } /* Handle PCR wraparound and resets */ if (GST_CLOCK_TIME_IS_VALID (pcr->last_pcrtime) && gstpcrtime < pcr->last_pcrtime) { if (pcr->last_pcrtime - gstpcrtime > PCR_GST_MAX_VALUE / 2) { /* PCR wraparound */ GST_DEBUG ("PCR wrap"); pcr->pcroffset += PCR_GST_MAX_VALUE; gstpcrtime = PCRTIME_TO_GSTTIME (pcrtime) + pcr->pcroffset; send_diff = gstpcrtime - pcr->base_pcrtime; } else if (GST_CLOCK_TIME_IS_VALID (time) && pcr->last_pcrtime - gstpcrtime > 15 * GST_SECOND) { /* Assume a reset */ GST_DEBUG ("PCR reset"); /* Calculate PCR we would have expected for the given input time, * essentially applying the reverse correction process * * We want to find the PCR offset to apply * pcroffset = (corrected) gstpcrtime - (received) gstpcrtime * * send_diff = (corrected) gstpcrtime - pcr->base_pcrtime * recv_diff = time - pcr->base_time * out_time = pcr->base_time + send_diff * * We are assuming that send_diff == recv_diff * (corrected) gstpcrtime - pcr->base_pcrtime = time - pcr->base_time * Giving us: * (corrected) gstpcrtime = time - pcr->base_time + pcr->base_pcrtime * * And therefore: * pcroffset = time - pcr->base_time + pcr->base_pcrtime - (received) gstpcrtime **/ pcr->pcroffset += time - pcr->base_time + pcr->base_pcrtime - gstpcrtime; gstpcrtime = PCRTIME_TO_GSTTIME (pcrtime) + pcr->pcroffset; send_diff = gstpcrtime - pcr->base_pcrtime; GST_DEBUG ("Introduced offset is now %" GST_TIME_FORMAT " corrected pcr time %" GST_TIME_FORMAT, GST_TIME_ARGS (pcr->pcroffset), GST_TIME_ARGS (gstpcrtime)); } else { GST_WARNING ("backward timestamps at server but no timestamps"); send_diff = 0; /* at least try to get a new timestamp.. */ pcr->base_time = GST_CLOCK_TIME_NONE; } } else send_diff = gstpcrtime - pcr->base_pcrtime; GST_DEBUG ("gstpcr %" GST_TIME_FORMAT ", buftime %" GST_TIME_FORMAT ", base %" GST_TIME_FORMAT ", send_diff %" GST_TIME_FORMAT, GST_TIME_ARGS (gstpcrtime), GST_TIME_ARGS (time), GST_TIME_ARGS (pcr->base_pcrtime), GST_TIME_ARGS (send_diff)); /* keep track of the last extended pcrtime */ pcr->last_pcrtime = gstpcrtime; /* we don't have an arrival timestamp so we can't do skew detection. we * should still apply a timestamp based on RTP timestamp and base_time */ if (!GST_CLOCK_TIME_IS_VALID (time) || !GST_CLOCK_TIME_IS_VALID (pcr->base_time)) goto no_skew; /* elapsed time at receiver, includes the jitter */ recv_diff = time - pcr->base_time; /* Ignore packets received at 100% the same time (i.e. from the same input buffer) */ if (G_UNLIKELY (time == pcr->prev_in_time && GST_CLOCK_TIME_IS_VALID (pcr->prev_in_time))) goto no_skew; /* measure the diff */ delta = ((gint64) recv_diff) - ((gint64) send_diff); #ifndef GST_DISABLE_GST_DEBUG /* measure the slope, this gives a rought estimate between the sender speed * and the receiver speed. This should be approximately 8, higher values * indicate a burst (especially when the connection starts) */ slope = recv_diff > 0 ? (send_diff * 8) / recv_diff : 8; #endif GST_DEBUG ("time %" GST_TIME_FORMAT ", base %" GST_TIME_FORMAT ", recv_diff %" GST_TIME_FORMAT ", slope %" G_GUINT64_FORMAT, GST_TIME_ARGS (time), GST_TIME_ARGS (pcr->base_time), GST_TIME_ARGS (recv_diff), slope); /* if the difference between the sender timeline and the receiver timeline * changed too quickly we have to resync because the server likely restarted * its timestamps. */ if (ABS (delta - pcr->skew) > GST_SECOND) { GST_WARNING ("delta - skew: %" GST_TIME_FORMAT " too big, reset skew", GST_TIME_ARGS (delta - pcr->skew)); mpegts_packetizer_resync (pcr, time, gstpcrtime, TRUE); send_diff = 0; delta = 0; } pos = pcr->window_pos; if (G_UNLIKELY (pcr->window_filling)) { /* we are filling the window */ GST_DEBUG ("filling %d, delta %" G_GINT64_FORMAT, pos, delta); pcr->window[pos++] = delta; /* calc the min delta we observed */ if (G_UNLIKELY (pos == 1 || delta < pcr->window_min)) pcr->window_min = delta; if (G_UNLIKELY (send_diff >= MAX_TIME || pos >= MAX_WINDOW)) { pcr->window_size = pos; /* window filled */ GST_DEBUG ("min %" G_GINT64_FORMAT, pcr->window_min); /* the skew is now the min */ pcr->skew = pcr->window_min; pcr->window_filling = FALSE; } else { gint perc_time, perc_window, perc; /* figure out how much we filled the window, this depends on the amount of * time we have or the max number of points we keep. */ perc_time = send_diff * 100 / MAX_TIME; perc_window = pos * 100 / MAX_WINDOW; perc = MAX (perc_time, perc_window); /* make a parabolic function, the closer we get to the MAX, the more value * we give to the scaling factor of the new value */ perc = perc * perc; /* quickly go to the min value when we are filling up, slowly when we are * just starting because we're not sure it's a good value yet. */ pcr->skew = (perc * pcr->window_min + ((10000 - perc) * pcr->skew)) / 10000; pcr->window_size = pos + 1; } } else { /* pick old value and store new value. We keep the previous value in order * to quickly check if the min of the window changed */ old = pcr->window[pos]; pcr->window[pos++] = delta; if (G_UNLIKELY (delta <= pcr->window_min)) { /* if the new value we inserted is smaller or equal to the current min, * it becomes the new min */ pcr->window_min = delta; } else if (G_UNLIKELY (old == pcr->window_min)) { gint64 min = G_MAXINT64; /* if we removed the old min, we have to find a new min */ for (i = 0; i < pcr->window_size; i++) { /* we found another value equal to the old min, we can stop searching now */ if (pcr->window[i] == old) { min = old; break; } if (pcr->window[i] < min) min = pcr->window[i]; } pcr->window_min = min; } /* average the min values */ pcr->skew = (pcr->window_min + (124 * pcr->skew)) / 125; GST_DEBUG ("delta %" G_GINT64_FORMAT ", new min: %" G_GINT64_FORMAT, delta, pcr->window_min); } /* wrap around in the window */ if (G_UNLIKELY (pos >= pcr->window_size)) pos = 0; pcr->window_pos = pos; no_skew: /* the output time is defined as the base timestamp plus the PCR time * adjusted for the clock skew .*/ if (pcr->base_time != -1) { out_time = pcr->base_time + send_diff; /* skew can be negative and we don't want to make invalid timestamps */ if (pcr->skew < 0 && out_time < -pcr->skew) { out_time = 0; } else { out_time += pcr->skew; } /* check if timestamps are not going backwards, we can only check this if we * have a previous out time and a previous send_diff */ if (G_LIKELY (pcr->prev_out_time != -1 && pcr->prev_send_diff != -1)) { /* now check for backwards timestamps */ if (G_UNLIKELY ( /* if the server timestamps went up and the out_time backwards */ (send_diff > pcr->prev_send_diff && out_time < pcr->prev_out_time) || /* if the server timestamps went backwards and the out_time forwards */ (send_diff < pcr->prev_send_diff && out_time > pcr->prev_out_time) || /* if the server timestamps did not change */ send_diff == pcr->prev_send_diff)) { GST_DEBUG ("backwards timestamps, using previous time"); out_time = GSTTIME_TO_MPEGTIME (out_time); } } } else { /* We simply use the pcrtime without applying any skew compensation */ out_time = time; } pcr->prev_out_time = out_time; pcr->prev_in_time = time; pcr->prev_send_diff = send_diff; GST_DEBUG ("skew %" G_GINT64_FORMAT ", out %" GST_TIME_FORMAT, pcr->skew, GST_TIME_ARGS (out_time)); return out_time; } static void record_pcr (MpegTSPacketizer2 * packetizer, MpegTSPCR * pcrtable, guint64 pcr, guint64 offset) { MpegTSPacketizerPrivate *priv = packetizer->priv; /* Check against first PCR */ if (pcrtable->first_pcr == -1 || pcrtable->first_offset > offset) { GST_DEBUG ("Recording first value. PCR:%" G_GUINT64_FORMAT " offset:%" G_GUINT64_FORMAT " pcr_pid:0x%04x", pcr, offset, pcrtable->pid); pcrtable->first_pcr = pcr; pcrtable->first_pcr_ts = PCRTIME_TO_GSTTIME (pcr); pcrtable->first_offset = offset; priv->nb_seen_offsets++; } else /* If we didn't update the first PCR, let's check against last PCR */ if (pcrtable->last_pcr == -1 || pcrtable->last_offset < offset) { GST_DEBUG ("Recording last value. PCR:%" G_GUINT64_FORMAT " offset:%" G_GUINT64_FORMAT " pcr_pid:0x%04x", pcr, offset, pcrtable->pid); if (G_UNLIKELY (pcrtable->first_pcr != -1 && pcr < pcrtable->first_pcr)) { GST_DEBUG ("rollover detected"); pcr += PCR_MAX_VALUE; } pcrtable->last_pcr = pcr; pcrtable->last_pcr_ts = PCRTIME_TO_GSTTIME (pcr); pcrtable->last_offset = offset; priv->nb_seen_offsets++; } } guint mpegts_packetizer_get_seen_pcr (MpegTSPacketizer2 * packetizer) { return packetizer->priv->nb_seen_offsets; } GstClockTime mpegts_packetizer_offset_to_ts (MpegTSPacketizer2 * packetizer, guint64 offset, guint16 pid) { MpegTSPacketizerPrivate *priv = packetizer->priv; MpegTSPCR *pcrtable; GstClockTime res; if (G_UNLIKELY (!packetizer->calculate_offset)) return GST_CLOCK_TIME_NONE; if (G_UNLIKELY (priv->refoffset == -1)) return GST_CLOCK_TIME_NONE; if (G_UNLIKELY (offset < priv->refoffset)) return GST_CLOCK_TIME_NONE; pcrtable = get_pcr_table (packetizer, pid); if (G_UNLIKELY (pcrtable->last_offset <= pcrtable->first_offset)) return GST_CLOCK_TIME_NONE; /* Convert byte difference into time difference */ res = PCRTIME_TO_GSTTIME (gst_util_uint64_scale (offset - priv->refoffset, pcrtable->last_pcr - pcrtable->first_pcr, pcrtable->last_offset - pcrtable->first_offset)); GST_DEBUG ("Returning timestamp %" GST_TIME_FORMAT " for offset %" G_GUINT64_FORMAT, GST_TIME_ARGS (res), offset); return res; } GstClockTime mpegts_packetizer_pts_to_ts (MpegTSPacketizer2 * packetizer, GstClockTime pts, guint16 pcr_pid) { GstClockTime res = GST_CLOCK_TIME_NONE; MpegTSPCR *pcrtable = get_pcr_table (packetizer, pcr_pid); /* Use clock skew if present */ if (packetizer->calculate_skew && GST_CLOCK_TIME_IS_VALID (pcrtable->base_time)) { GST_DEBUG ("pts %" G_GUINT64_FORMAT " base_pcrtime:%" G_GUINT64_FORMAT " base_time:%" GST_TIME_FORMAT, pts, pcrtable->base_pcrtime, GST_TIME_ARGS (pcrtable->base_time)); res = pts + pcrtable->pcroffset - pcrtable->base_pcrtime + pcrtable->base_time + pcrtable->skew; } else /* If not, use pcr observations */ if (packetizer->calculate_offset && pcrtable->first_pcr != -1) { /* Rollover */ if (G_UNLIKELY (pts < pcrtable->first_pcr_ts)) pts += MPEGTIME_TO_GSTTIME (PTS_DTS_MAX_VALUE); res = pts - pcrtable->first_pcr_ts; } else GST_WARNING ("Not enough information to calculate proper timestamp"); GST_DEBUG ("Returning timestamp %" GST_TIME_FORMAT " for pts %" GST_TIME_FORMAT " pcr_pid:0x%04x", GST_TIME_ARGS (res), GST_TIME_ARGS (pts), pcr_pid); return res; } guint64 mpegts_packetizer_ts_to_offset (MpegTSPacketizer2 * packetizer, GstClockTime ts, guint16 pcr_pid) { MpegTSPacketizerPrivate *priv = packetizer->priv; MpegTSPCR *pcrtable; guint64 res; if (!packetizer->calculate_offset) return -1; pcrtable = get_pcr_table (packetizer, pcr_pid); if (pcrtable->first_pcr == -1) return -1; GST_DEBUG ("ts(pcr) %" G_GUINT64_FORMAT " first_pcr:%" G_GUINT64_FORMAT, GSTTIME_TO_MPEGTIME (ts), pcrtable->first_pcr); /* Convert ts to PCRTIME */ res = gst_util_uint64_scale (GSTTIME_TO_PCRTIME (ts), pcrtable->last_offset - pcrtable->first_offset, pcrtable->last_pcr - pcrtable->first_pcr); res += pcrtable->first_offset + priv->refoffset; GST_DEBUG ("Returning offset %" G_GUINT64_FORMAT " for ts %" GST_TIME_FORMAT, res, GST_TIME_ARGS (ts)); return res; } void mpegts_packetizer_set_reference_offset (MpegTSPacketizer2 * packetizer, guint64 refoffset) { GST_DEBUG ("Setting reference offset to %" G_GUINT64_FORMAT, refoffset); packetizer->priv->refoffset = refoffset; }