libswscale/swscale.c:1066: error: Uninitialized Value
  The value read from A was never initialized.

libswscale/swscale.c:1066:21: 
1064.             if (CONFIG_SWSCALE_ALPHA && c->alpPixBuf){
1065.                 YSCALE_YUV_2_RGBX_FULL_C(1<<21, 1)
1066.                     dest[aidx]= A;
                          ^
1067.                     dest[0]= B>>22;
1068.                     dest[1]= G>>22;
