libswscale/output.c:1219: error: Uninitialized Value
  The value read from A was never initialized.

libswscale/output.c:1219:23: 
1217.             dest[1] = G >> 22;
1218.             dest[2] = B >> 22;
1219.             dest[3] = hasAlpha ? A : 255;
                            ^
1220.             break;
1221.         case AV_PIX_FMT_ABGR:
