matroskamux: correctly handle negative relative timestamps

... rather than scaling these as unsigned.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=712744

Based on patch by Krzysztof Kotlenga <pocek@users.sf.net>

diff --git a/gst/matroska/matroska-mux.c b/gst/matroska/matroska-mux.c
index e8b64f6480cf48d40de93f3e50330411d966e5a5..e1cf9ea27f4b3f0033e1d5ee12818e3b677d2f75 100644 (file)
--- a/gst/matroska/matroska-mux.c
+++ b/gst/matroska/matroska-mux.c
@@ -3381,12 +3381,15 @@ gst_matroska_mux_write_data (GstMatroskaMux * mux, GstMatroskaPad * collect_pad,
   if (relative_timestamp64 >= 0) {
     /* round the timestamp */
     relative_timestamp64 += gst_util_uint64_scale (mux->time_scale, 1, 2);
+    relative_timestamp = gst_util_uint64_scale (relative_timestamp64, 1,
+        mux->time_scale);
   } else {
     /* round the timestamp */
     relative_timestamp64 -= gst_util_uint64_scale (mux->time_scale, 1, 2);
+    relative_timestamp =
+        -((gint16) gst_util_uint64_scale (-relative_timestamp64, 1,
+            mux->time_scale));
   }
-  relative_timestamp = gst_util_uint64_scale (relative_timestamp64, 1,
-      mux->time_scale);
 
   if (is_video_invisible)
     flags |= 0x08;