dashdemux: Fix handling of live streams with timeshift buffers.

By implementing get_live_seek_range.

As shown by :

gst-validate-1.0 playbin \
uri=http://dev-iplatforms.kw.bbc.co.uk/dash/news24-avc3/news24.php

This patch handles live seeking, by setting a live seek range
comprised between now - timeShiftBufferDepth and now.

The inteersting thing with this stream is that one can actually
ask fragments up to availabilityStartTime, but it seems quite clear
in the spec that content is only guaranteed to exist up to
timeShiftBufferDepth.

One can test live seeking this way :

gst-validate-1.0 playbin \
uri=http://dev-iplatforms.kw.bbc.co.uk/dash/news24-avc3/news24.php \
--set-scenario seek_back.scenario

with scenario being:

description, seek=true
seek, playback-time=position+5.0, start="position-600.0",
flags=accurate+flush

This example will play the stream, wait for five seconds, then seek back
to a position 10 minutes earlier.

https://bugzilla.gnome.org/show_bug.cgi?id=744362
This commit is contained in:
Mathieu Duponchelle 2015-02-12 22:06:17 +01:00
parent 6b864813cc
commit 7ca6d9634a

View file

@ -262,6 +262,25 @@ gst_dash_demux_dispose (GObject * obj)
G_OBJECT_CLASS (parent_class)->dispose (obj);
}
static gboolean
gst_dash_demux_get_live_seek_range (GstAdaptiveDemux * demux, gint64 * start,
gint64 * stop)
{
GstDashDemux *self = GST_DASH_DEMUX (demux);
GDateTime *now = g_date_time_new_now_utc ();
GDateTime *mstart =
gst_date_time_to_g_date_time (self->client->mpd_node->availabilityStartTime);
GTimeSpan stream_now;
stream_now = g_date_time_difference (now, mstart);
g_date_time_unref (now);
g_date_time_unref (mstart);
*stop = stream_now * GST_USECOND;
*start = *stop - (self->client->mpd_node->timeShiftBufferDepth * GST_MSECOND);
return TRUE;
}
static void
gst_dash_demux_class_init (GstDashDemuxClass * klass)
{
@ -338,6 +357,7 @@ gst_dash_demux_class_init (GstDashDemuxClass * klass)
gstadaptivedemux_class->stream_update_fragment_info =
gst_dash_demux_stream_update_fragment_info;
gstadaptivedemux_class->stream_free = gst_dash_demux_stream_free;
gstadaptivedemux_class->get_live_seek_range = gst_dash_demux_get_live_seek_range;
}
static void