video: ensure sign in scale function

diff --git a/gst-libs/gst/video/video.h b/gst-libs/gst/video/video.h
index 6701aa1..dfad7b6 100644 (file)
--- a/gst-libs/gst/video/video.h
+++ b/gst-libs/gst/video/video.h
@@ -272,7 +272,7 @@ struct _GstVideoFormatInfo {
 #define GST_VIDEO_FORMAT_INFO_W_SUB(info,c)      ((info)->w_sub[c])
 #define GST_VIDEO_FORMAT_INFO_H_SUB(info,c)      ((info)->h_sub[c])
 
-#define GST_VIDEO_SUB_SCALE(scale,val)   (-((-(val))>>(scale)))
+#define GST_VIDEO_SUB_SCALE(scale,val)   (-((-((gint)val))>>(scale)))
 
 #define GST_VIDEO_FORMAT_INFO_SCALE_WIDTH(info,c,w)  GST_VIDEO_SUB_SCALE ((info)->w_sub[(c)],(w))
 #define GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT(info,c,h) GST_VIDEO_SUB_SCALE ((info)->h_sub[(c)],(h))