gstreamer/ext/dash/gstdashdemux.h
Alex Ashley c8ef39cac7 dashdemux: provide a default suggestedPresentationDelay
If MPD@suggestedPresentationDelay is not present in the manifest,
dashdemux selects the fragment closest to the most recently generated
fragment. This causes a playback issue because this choice does not allow
the DASH client to build up any buffer of downloaded fragments without
pausing playback. This is because by definition new fragments appear on
the server in real-time (e.g. if segment duration is 4 seconds, a new
fragment will appear on the server every 4 seconds). If the starting
playback position was n*segmentDuration seconds behind "now", the DASH
client could download up to 'n' fragments faster than realtime before it
reached the point where it needed to wait for fragments to appear on the
server.

The MPD@suggestedPresentationDelay attribute allows a content publisher
to provide a suggested starting position that is behind the current
"live" position.

If the MPD@suggestedPresentationDelay attribute is not present, provide
a suitable default value as a property of the dashdemux element. To
allow the default presentation delay to be specified either using
fragments or seconds, the property is a string that contains a number
and a unit (e.g. "10 seconds", "4 fragments", "2500ms").
2015-10-29 13:26:46 +00:00

115 lines
3.3 KiB
C

/*
* DASH demux plugin for GStreamer
*
* gstdashdemux.h
*
* Copyright (C) 2012 Orange
* Authors:
* David Corvoysier <david.corvoysier@orange.com>
* Hamid Zakari <hamid.zakari@gmail.com>
*
* Copyright (C) 2013 Smart TV Alliance
* Author: Thiago Sousa Santos <thiago.sousa.santos@collabora.com>, Collabora Ltd.
*
* 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 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library (COPYING); if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __GST_DASH_DEMUX_H__
#define __GST_DASH_DEMUX_H__
#include <gst/gst.h>
#include <gst/adaptivedemux/gstadaptivedemux.h>
#include <gst/base/gstadapter.h>
#include <gst/base/gstdataqueue.h>
#include "gstmpdparser.h"
#include "gstisoff.h"
#include <gst/uridownloader/gsturidownloader.h>
G_BEGIN_DECLS
#define GST_TYPE_DASH_DEMUX \
(gst_dash_demux_get_type())
#define GST_DASH_DEMUX(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_DASH_DEMUX,GstDashDemux))
#define GST_DASH_DEMUX_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_DASH_DEMUX,GstDashDemuxClass))
#define GST_IS_DASH_DEMUX(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_DASH_DEMUX))
#define GST_IS_DASH_DEMUX_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_DASH_DEMUX))
#define GST_DASH_DEMUX_CAST(obj) \
((GstDashDemux *)obj)
typedef struct _GstDashDemuxClockDrift GstDashDemuxClockDrift;
typedef struct _GstDashDemuxStream GstDashDemuxStream;
typedef struct _GstDashDemux GstDashDemux;
typedef struct _GstDashDemuxClass GstDashDemuxClass;
struct _GstDashDemuxStream
{
GstAdaptiveDemuxStream parent;
gint index;
GstActiveStream *active_stream;
GstMediaFragmentInfo current_fragment;
/* index parsing */
GstSidxParser sidx_parser;
gsize sidx_current_remaining;
gint sidx_index;
gint64 sidx_base_offset;
GstClockTime pending_seek_ts;
};
/**
* GstDashDemux:
*
* Opaque #GstDashDemux data structure.
*/
struct _GstDashDemux
{
GstAdaptiveDemux parent;
GSList *next_periods;
GstMpdClient *client; /* MPD client */
GMutex client_lock;
GstDashDemuxClockDrift *clock_drift;
gboolean end_of_period;
gboolean end_of_manifest;
/* Properties */
GstClockTime max_buffering_time; /* Maximum buffering time accumulated during playback */
guint64 max_bitrate; /* max of bitrate supported by target decoder */
gchar* default_presentation_delay; /* presentation time delay if MPD@suggestedPresentationDelay is not present */
gint n_audio_streams;
gint n_video_streams;
gint n_subtitle_streams;
};
struct _GstDashDemuxClass
{
GstAdaptiveDemuxClass parent_class;
};
GType gst_dash_demux_get_type (void);
G_END_DECLS
#endif /* __GST_DASH_DEMUX_H__ */