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8c60e42070
Helps with debugging issues. And also remove unused variable (opcr) This will also allow us in the future to properly detect: * random-access location (to enable keyframe observation and potentially seeking * discont location (to properly handle resets) * splice location (to properly handle new stream changes)
1628 lines
52 KiB
C
1628 lines
52 KiB
C
/*
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* mpegtspacketizer.c -
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* Copyright (C) 2007, 2008 Alessandro Decina, Zaheer Merali
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*
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* Authors:
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* Zaheer Merali <zaheerabbas at merali dot org>
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* Alessandro Decina <alessandro@nnva.org>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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* Boston, MA 02110-1301, USA.
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*/
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#include <string.h>
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#include <stdlib.h>
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/* Skew calculation pameters */
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#define MAX_TIME (2 * GST_SECOND)
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/* maximal PCR time */
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#define PCR_MAX_VALUE (((((guint64)1)<<33) * 300) + 298)
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#define PCR_GST_MAX_VALUE (PCR_MAX_VALUE * GST_MSECOND / (27000))
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#define PTS_DTS_MAX_VALUE (((guint64)1) << 33)
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#include "mpegtspacketizer.h"
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#include "gstmpegdesc.h"
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GST_DEBUG_CATEGORY_STATIC (mpegts_packetizer_debug);
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#define GST_CAT_DEFAULT mpegts_packetizer_debug
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#define MPEGTS_PACKETIZER_GET_PRIVATE(obj) \
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(G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_MPEGTS_PACKETIZER, MpegTSPacketizerPrivate))
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static void _init_local (void);
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G_DEFINE_TYPE_EXTENDED (MpegTSPacketizer2, mpegts_packetizer, G_TYPE_OBJECT, 0,
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_init_local ());
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/* Maximum number of MpegTSPcr
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* 256 should be sufficient for most multiplexes */
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#define MAX_PCR_OBS_CHANNELS 256
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typedef struct _MpegTSPCR
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{
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guint16 pid;
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/* Following variables are only active/used when
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* calculate_skew is TRUE */
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GstClockTime base_time;
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GstClockTime base_pcrtime;
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GstClockTime prev_out_time;
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GstClockTime prev_in_time;
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GstClockTime last_pcrtime;
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gint64 window[MAX_WINDOW];
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guint window_pos;
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guint window_size;
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gboolean window_filling;
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gint64 window_min;
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gint64 skew;
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gint64 prev_send_diff;
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/* Offset to apply to PCR to handle wraparounds */
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guint64 pcroffset;
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/* Used for bitrate calculation */
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/* FIXME : Replace this later on with a balanced tree or sequence */
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guint64 first_offset;
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guint64 first_pcr;
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GstClockTime first_pcr_ts;
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guint64 last_offset;
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guint64 last_pcr;
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GstClockTime last_pcr_ts;
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} MpegTSPCR;
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struct _MpegTSPacketizerPrivate
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{
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/* Shortcuts for adapter usage */
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guint available;
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guint8 *mapped;
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guint offset;
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guint mapped_size;
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/* Reference offset */
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guint64 refoffset;
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guint nb_seen_offsets;
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/* Last inputted timestamp */
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GstClockTime last_in_time;
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/* offset to observations table */
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guint8 pcrtablelut[0x2000];
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MpegTSPCR *observations[MAX_PCR_OBS_CHANNELS];
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guint8 lastobsid;
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};
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static void mpegts_packetizer_dispose (GObject * object);
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static void mpegts_packetizer_finalize (GObject * object);
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static GstClockTime calculate_skew (MpegTSPCR * pcr, guint64 pcrtime,
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GstClockTime time);
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static void record_pcr (MpegTSPacketizer2 * packetizer, MpegTSPCR * pcrtable,
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guint64 pcr, guint64 offset);
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#define CONTINUITY_UNSET 255
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#define VERSION_NUMBER_UNSET 255
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#define TABLE_ID_UNSET 0xFF
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#define PACKET_SYNC_BYTE 0x47
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static inline MpegTSPCR *
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get_pcr_table (MpegTSPacketizer2 * packetizer, guint16 pid)
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{
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MpegTSPacketizerPrivate *priv = packetizer->priv;
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MpegTSPCR *res;
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res = priv->observations[priv->pcrtablelut[pid]];
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if (G_UNLIKELY (res == NULL)) {
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/* If we don't have a PCR table for the requested PID, create one .. */
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res = g_new0 (MpegTSPCR, 1);
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/* Add it to the last table position */
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priv->observations[priv->lastobsid] = res;
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/* Update the pcrtablelut */
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priv->pcrtablelut[pid] = priv->lastobsid;
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/* And increment the last know slot */
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priv->lastobsid++;
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/* Finally set the default values */
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res->pid = pid;
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res->first_offset = -1;
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res->first_pcr = -1;
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res->first_pcr_ts = GST_CLOCK_TIME_NONE;
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res->last_offset = -1;
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res->last_pcr = -1;
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res->last_pcr_ts = GST_CLOCK_TIME_NONE;
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res->base_time = GST_CLOCK_TIME_NONE;
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res->base_pcrtime = GST_CLOCK_TIME_NONE;
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res->last_pcrtime = GST_CLOCK_TIME_NONE;
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res->window_pos = 0;
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res->window_filling = TRUE;
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res->window_min = 0;
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res->skew = 0;
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res->prev_send_diff = GST_CLOCK_TIME_NONE;
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res->prev_out_time = GST_CLOCK_TIME_NONE;
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res->pcroffset = 0;
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}
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return res;
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}
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static void
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flush_observations (MpegTSPacketizer2 * packetizer)
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{
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MpegTSPacketizerPrivate *priv = packetizer->priv;
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gint i;
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for (i = 0; i < priv->lastobsid; i++) {
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g_free (priv->observations[i]);
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priv->observations[i] = NULL;
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}
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memset (priv->pcrtablelut, 0xff, 0x200);
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priv->lastobsid = 0;
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}
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static inline MpegTSPacketizerStreamSubtable *
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find_subtable (GSList * subtables, guint8 table_id, guint16 subtable_extension)
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{
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GSList *tmp;
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/* FIXME: Make this an array ! */
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for (tmp = subtables; tmp; tmp = tmp->next) {
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MpegTSPacketizerStreamSubtable *sub =
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(MpegTSPacketizerStreamSubtable *) tmp->data;
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if (sub->table_id == table_id
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&& sub->subtable_extension == subtable_extension)
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return sub;
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}
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return FALSE;
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}
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static gboolean
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seen_section_before (MpegTSPacketizerStream * stream, guint8 table_id,
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guint16 subtable_extension, guint8 version_number, guint8 section_number,
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guint8 last_section_number)
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{
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MpegTSPacketizerStreamSubtable *subtable;
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/* Check if we've seen this table_id/subtable_extension first */
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subtable = find_subtable (stream->subtables, table_id, subtable_extension);
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if (!subtable) {
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GST_DEBUG ("Haven't seen subtale");
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return FALSE;
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}
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/* If we have, check it has the same version_number */
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if (subtable->version_number != version_number) {
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GST_DEBUG ("Different version number");
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return FALSE;
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}
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/* Did the number of sections change ? */
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if (subtable->last_section_number != last_section_number) {
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GST_DEBUG ("Different last_section_number");
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return FALSE;
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}
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/* Finally return whether we saw that section or not */
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return MPEGTS_BIT_IS_SET (subtable->seen_section, section_number);
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}
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static MpegTSPacketizerStreamSubtable *
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mpegts_packetizer_stream_subtable_new (guint8 table_id,
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guint16 subtable_extension, guint8 last_section_number)
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{
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MpegTSPacketizerStreamSubtable *subtable;
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subtable = g_new0 (MpegTSPacketizerStreamSubtable, 1);
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subtable->version_number = VERSION_NUMBER_UNSET;
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subtable->table_id = table_id;
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subtable->subtable_extension = subtable_extension;
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subtable->last_section_number = last_section_number;
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return subtable;
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}
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static MpegTSPacketizerStream *
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mpegts_packetizer_stream_new (guint16 pid)
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{
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MpegTSPacketizerStream *stream;
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stream = (MpegTSPacketizerStream *) g_new0 (MpegTSPacketizerStream, 1);
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stream->continuity_counter = CONTINUITY_UNSET;
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stream->subtables = NULL;
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stream->table_id = TABLE_ID_UNSET;
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stream->pid = pid;
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return stream;
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}
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static void
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mpegts_packetizer_clear_section (MpegTSPacketizerStream * stream)
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{
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stream->continuity_counter = CONTINUITY_UNSET;
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stream->section_length = 0;
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stream->section_offset = 0;
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stream->table_id = TABLE_ID_UNSET;
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if (stream->section_data)
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g_free (stream->section_data);
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stream->section_data = NULL;
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}
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static void
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mpegts_packetizer_stream_subtable_free (MpegTSPacketizerStreamSubtable *
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subtable)
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{
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g_free (subtable);
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}
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static void
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mpegts_packetizer_stream_free (MpegTSPacketizerStream * stream)
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{
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mpegts_packetizer_clear_section (stream);
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if (stream->section_data)
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g_free (stream->section_data);
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g_slist_foreach (stream->subtables,
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(GFunc) mpegts_packetizer_stream_subtable_free, NULL);
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g_slist_free (stream->subtables);
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g_free (stream);
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}
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static void
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mpegts_packetizer_class_init (MpegTSPacketizer2Class * klass)
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{
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GObjectClass *gobject_class;
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g_type_class_add_private (klass, sizeof (MpegTSPacketizerPrivate));
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gobject_class = G_OBJECT_CLASS (klass);
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gobject_class->dispose = mpegts_packetizer_dispose;
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gobject_class->finalize = mpegts_packetizer_finalize;
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}
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static void
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mpegts_packetizer_init (MpegTSPacketizer2 * packetizer)
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{
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MpegTSPacketizerPrivate *priv;
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priv = packetizer->priv = MPEGTS_PACKETIZER_GET_PRIVATE (packetizer);
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packetizer->adapter = gst_adapter_new ();
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packetizer->offset = 0;
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packetizer->empty = TRUE;
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packetizer->streams = g_new0 (MpegTSPacketizerStream *, 8192);
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packetizer->packet_size = 0;
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packetizer->calculate_skew = FALSE;
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packetizer->calculate_offset = FALSE;
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priv->available = 0;
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priv->mapped = NULL;
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priv->mapped_size = 0;
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priv->offset = 0;
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memset (priv->pcrtablelut, 0xff, 0x200);
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memset (priv->observations, 0x0, sizeof (priv->observations));
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priv->lastobsid = 0;
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priv->nb_seen_offsets = 0;
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priv->refoffset = -1;
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priv->last_in_time = GST_CLOCK_TIME_NONE;
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}
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static void
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mpegts_packetizer_dispose (GObject * object)
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{
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MpegTSPacketizer2 *packetizer = GST_MPEGTS_PACKETIZER (object);
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if (!packetizer->disposed) {
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if (packetizer->packet_size)
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packetizer->packet_size = 0;
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if (packetizer->streams) {
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int i;
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for (i = 0; i < 8192; i++) {
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if (packetizer->streams[i])
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mpegts_packetizer_stream_free (packetizer->streams[i]);
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}
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g_free (packetizer->streams);
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}
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gst_adapter_clear (packetizer->adapter);
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g_object_unref (packetizer->adapter);
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packetizer->disposed = TRUE;
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packetizer->offset = 0;
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packetizer->empty = TRUE;
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flush_observations (packetizer);
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}
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if (G_OBJECT_CLASS (mpegts_packetizer_parent_class)->dispose)
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G_OBJECT_CLASS (mpegts_packetizer_parent_class)->dispose (object);
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}
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static void
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mpegts_packetizer_finalize (GObject * object)
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{
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if (G_OBJECT_CLASS (mpegts_packetizer_parent_class)->finalize)
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G_OBJECT_CLASS (mpegts_packetizer_parent_class)->finalize (object);
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}
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static inline guint64
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mpegts_packetizer_compute_pcr (const guint8 * data)
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{
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guint32 pcr1;
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guint16 pcr2;
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guint64 pcr, pcr_ext;
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pcr1 = GST_READ_UINT32_BE (data);
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pcr2 = GST_READ_UINT16_BE (data + 4);
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pcr = ((guint64) pcr1) << 1;
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pcr |= (pcr2 & 0x8000) >> 15;
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pcr_ext = (pcr2 & 0x01ff);
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return pcr * 300 + pcr_ext % 300;
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}
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static gboolean
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mpegts_packetizer_parse_adaptation_field_control (MpegTSPacketizer2 *
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packetizer, MpegTSPacketizerPacket * packet)
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{
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guint8 length, afcflags;
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guint8 *data;
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length = *packet->data++;
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/* an adaptation field with length 0 is valid and
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* can be used to insert a single stuffing byte */
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if (!length) {
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packet->afc_flags = 0;
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return TRUE;
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}
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if (FLAGS_HAS_AFC (packet->scram_afc_cc)) {
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/* no payload, adaptation field of 183 bytes */
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if (length != 183) {
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GST_DEBUG ("PID %d afc == 0x%02x and length %d != 183",
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packet->pid, packet->scram_afc_cc & 0x30, length);
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}
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} else if (length > 182) {
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GST_DEBUG ("PID %d afc == 0x%02x and length %d > 182",
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packet->pid, packet->scram_afc_cc & 0x30, length);
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}
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if (packet->data + length > packet->data_end) {
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GST_DEBUG ("PID %d afc length %d overflows the buffer current %d max %d",
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packet->pid, length, (gint) (packet->data - packet->data_start),
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(gint) (packet->data_end - packet->data_start));
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return FALSE;
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}
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data = packet->data;
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packet->data += length;
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afcflags = packet->afc_flags = *data++;
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GST_DEBUG ("flags: %s%s%s%s%s%s%s%s%s",
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afcflags & 0x80 ? "discontinuity " : "",
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afcflags & 0x40 ? "random_access " : "",
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afcflags & 0x20 ? "elementary_stream_priority " : "",
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afcflags & 0x10 ? "PCR " : "",
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afcflags & 0x08 ? "OPCR " : "",
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afcflags & 0x04 ? "splicing_point " : "",
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afcflags & 0x02 ? "transport_private_data " : "",
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afcflags & 0x01 ? "extension " : "", afcflags == 0x00 ? "<none>" : "");
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/* PCR */
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if (afcflags & MPEGTS_AFC_PCR_FLAG) {
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MpegTSPCR *pcrtable = NULL;
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packet->pcr = mpegts_packetizer_compute_pcr (data);
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data += 6;
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GST_DEBUG ("pcr 0x%04x %" G_GUINT64_FORMAT " (%" GST_TIME_FORMAT
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") offset:%" G_GUINT64_FORMAT, packet->pid, packet->pcr,
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GST_TIME_ARGS (PCRTIME_TO_GSTTIME (packet->pcr)), packet->offset);
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if (packetizer->calculate_skew
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&& GST_CLOCK_TIME_IS_VALID (packetizer->priv->last_in_time)) {
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pcrtable = get_pcr_table (packetizer, packet->pid);
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calculate_skew (pcrtable, packet->pcr, packetizer->priv->last_in_time);
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}
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if (packetizer->calculate_offset) {
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if (!pcrtable)
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pcrtable = get_pcr_table (packetizer, packet->pid);
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record_pcr (packetizer, pcrtable, packet->pcr, packet->offset);
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}
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}
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#ifndef GST_DISABLE_GST_DEBUG
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/* OPCR */
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if (afcflags & MPEGTS_AFC_OPCR_FLAG) {
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/* Note: We don't use/need opcr for the time being */
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guint64 opcr = mpegts_packetizer_compute_pcr (data);
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data += 6;
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GST_DEBUG ("opcr %" G_GUINT64_FORMAT " (%" GST_TIME_FORMAT ")",
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opcr, GST_TIME_ARGS (PCRTIME_TO_GSTTIME (opcr)));
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}
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if (afcflags & MPEGTS_AFC_SPLICING_POINT_FLAG) {
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GST_DEBUG ("splice_countdown: %u", *data++);
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}
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if (afcflags & MPEGTS_AFC_TRANSPORT_PRIVATE_DATA_FLAG) {
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guint8 len = *data++;
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GST_MEMDUMP ("private data", data, len);
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data += len;
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}
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if (afcflags & MPEGTS_AFC_EXTENSION_FLAG) {
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guint8 extlen = *data++;
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guint8 flags = *data++;
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GST_DEBUG ("extension size:%d flags : %s%s%s", extlen,
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flags & 0x80 ? "ltw " : "",
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flags & 0x40 ? "piecewise_rate " : "",
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flags & 0x20 ? "seamless_splice " : "");
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if (flags & 0x80) {
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GST_DEBUG ("legal time window: valid_flag:%d offset:%d", *data >> 7,
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GST_READ_UINT16_BE (data) & 0x7fff);
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data += 2;
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}
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}
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#endif
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return TRUE;
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}
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static MpegTSPacketizerPacketReturn
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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 */
|
|
for (; sync_offset < priv->mapped_size; sync_offset++)
|
|
if (priv->mapped[sync_offset] == 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;
|
|
}
|