lavc,lavfi: fix calculating the plane size in the AVBufferRef wrappers

It is supposed to be height * linesize, not width * linesize.
Thanks to Hendrik Leppkes for pointing out the bug.

libavcodec/utils.c

@@ -667,8 +667,8 @@ do {                                                                    \
             planes = (desc->flags & PIX_FMT_PLANAR) ? desc->nb_components : 1;
 
             for (i = 0; i < planes; i++) {
-                int h_shift    = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
-                int plane_size = (frame->width >> h_shift) * frame->linesize[i];
+                int v_shift    = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
+                int plane_size = (frame->height >> v_shift) * frame->linesize[i];
 
                 WRAP_PLANE(frame->buf[i], frame->data[i], plane_size);
             }

libavfilter/buffersrc.c

@@ -193,8 +193,8 @@ do {                                                                    \
         planes = (desc->flags & PIX_FMT_PLANAR) ? desc->nb_components : 1;
 
         for (i = 0; i < planes; i++) {
-            int h_shift    = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
-            int plane_size = (frame->width >> h_shift) * frame->linesize[i];
+            int v_shift    = (i == 1 || i == 2) ? desc->log2_chroma_w : 0;
+            int plane_size = (frame->height >> v_shift) * frame->linesize[i];
 
             WRAP_PLANE(frame->buf[i], frame->data[i], plane_size);
         }