rem: g_return_if_fail (GST_IS_VIDEO_WIDGET (bvw->priv->vw));
context: bacon_video_widget_set_scale_ratio (BaconVideoWidget * bvw, gfloat ratio){  g_return_if_fail (bvw != NULL);  g_return_if_fail (BACON_IS_VIDEO_WIDGET (bvw));  g_return_if_fail (GST_IS_ELEMENT (bvw->priv->play));  g_return_if_fail (GST_IS_VIDEO_WIDGET (bvw->priv->vw));  gst_video_widget_set_scale (bvw->priv->vw, ratio);  gst_video_widget_set_scale_override (bvw->priv->vw, TRUE);  shrink_toplevel (bvw);}