matroskademux: Better calculation of framerate

https://bugzilla.gnome.org/show_bug.cgi?id=647833
This commit is contained in:
David Schleef 2011-04-14 23:24:56 -07:00 committed by Tim-Philipp Müller
parent c8b5014892
commit 41f3b30010

View file

@ -6317,6 +6317,31 @@ gst_matroska_demux_sink_activate_pull (GstPad * sinkpad, gboolean active)
return TRUE;
}
static void
gst_duration_to_fraction (guint64 duration, gint * dest_n, gint * dest_d)
{
static const int common_den[] = { 1, 2, 3, 4, 1001 };
int n, d;
int i;
guint64 a;
for (i = 0; i < G_N_ELEMENTS (common_den); i++) {
d = common_den[i];
n = floor (0.5 + (d * 1e9) / duration);
a = gst_util_uint64_scale_int (1000000000, d, n);
if (duration >= a - 1 && duration <= a + 1) {
goto out;
}
}
gst_util_double_to_fraction (1e9 / duration, &n, &d);
out:
/* set results */
*dest_n = n;
*dest_d = d;
}
static GstCaps *
gst_matroska_demux_video_caps (GstMatroskaTrackVideoContext *
videocontext, const gchar * codec_id, guint8 * data, guint size,
@ -6612,21 +6637,15 @@ gst_matroska_demux_video_caps (GstMatroskaTrackVideoContext *
g_value_unset (&fps_double);
g_value_unset (&fps_fraction);
} else if (context->default_duration > 0) {
GValue fps_double = { 0, };
GValue fps_fraction = { 0, };
int fps_n, fps_d;
g_value_init (&fps_double, G_TYPE_DOUBLE);
g_value_init (&fps_fraction, GST_TYPE_FRACTION);
g_value_set_double (&fps_double, (gdouble) GST_SECOND /
gst_guint64_to_gdouble (context->default_duration));
g_value_transform (&fps_double, &fps_fraction);
gst_duration_to_fraction (context->default_duration, &fps_n, &fps_d);
GST_DEBUG ("using default duration %" G_GUINT64_FORMAT,
context->default_duration);
GST_INFO ("using default duration %" G_GUINT64_FORMAT
" framerate %d/%d", context->default_duration, fps_n, fps_d);
gst_structure_set_value (structure, "framerate", &fps_fraction);
g_value_unset (&fps_double);
g_value_unset (&fps_fraction);
gst_structure_set (structure, "framerate", GST_TYPE_FRACTION,
fps_n, fps_d, NULL);
} else {
/* sort of a hack to get most codecs to support,
* even if the default_duration is missing */