+ * The @GST_SEEK_FLAG_SNAP_BEFORE flag can be used to snap to the previous
+ * relevant location, and the @GST_SEEK_FLAG_SNAP_AFTER flag can be used to
+ * select the next relevant location. If KEY_UNIT is specified, the relevant
+ * location is a keyframe. If both flags are specified, the nearest of these
+ * locations will be selected. If none are specified, the implementation is
+ * free to select whichever it wants.
+ * The before and after here are in running time, so when playing backwards,
+ * the next location refers to the one that will played in next, and not the
+ * one that is located after in the actual source stream.
+ *