theoradec: return GST_CLOCK_TIME_NONE for negative framecounts.

This fixes most seeking issues when used with gnonlin.
Fixes #543591

diff --git a/ext/theora/theoradec.c b/ext/theora/theoradec.c
index 60e2ef2..78b5e08 100644 (file)
--- a/ext/theora/theoradec.c
+++ b/ext/theora/theoradec.c
@@ -255,6 +255,8 @@ _theora_granule_start_time (GstTheoraDec * dec, gint64 granulepos)
   if ((framecount = _theora_granule_frame (dec, granulepos)) < 0)
     return GST_CLOCK_TIME_NONE;
 
+  if (framecount < 0)
+    return GST_CLOCK_TIME_NONE;
   return gst_util_uint64_scale_int (framecount * GST_SECOND,
       dec->info.fps_denominator, dec->info.fps_numerator);
 }