Replace sizeof(short) by the more robust sizeof(*s->pblocks[i]) in memset and

memcpy calls.  s->pblocks is the element actually being handled.

Originally committed as revision 17404 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mpegvideo_xvmc.c

@@ -281,7 +281,7 @@ void ff_xvmc_decode_mb(MpegEncContext *s)
     if (s->flags & CODEC_FLAG_GRAY) {
         if (s->mb_intra) {                                   // intra frames are always full chroma blocks
             for (i = 4; i < blocks_per_mb; i++) {
-                memset(s->pblocks[i], 0, sizeof(short)*64);  // so we need to clear them
+                memset(s->pblocks[i], 0, sizeof(*s->pblocks[i])*64);  // so we need to clear them
                 if (!render->unsigned_intra)
                     s->pblocks[i][0] = 1 << 10;
             }
@@ -309,7 +309,7 @@ void ff_xvmc_decode_mb(MpegEncContext *s)
             // copy blocks only if the codec doesn't support pblocks reordering
             if (s->avctx->xvmc_acceleration == 1) {
                 memcpy(&render->data_blocks[render->next_free_data_block_num*64],
-                       s->pblocks[i], sizeof(short)*64);
+                       s->pblocks[i], sizeof(*s->pblocks[i])*64);
             }
             render->next_free_data_block_num++;
         }