aic: Fix decoding files with odd dimensions

Normally the aic decoder finds the proper slice combination (multiple of
some number less than 32) but in case of odd width, it resorts to the
default values, which were actually swapped.
The number of slices is modified to account for such odd width cases.

CC: libav-stable@libav.org

libavcodec/aic.c

@@ -434,8 +434,8 @@ static av_cold int aic_decode_init(AVCodecContext *avctx)
     ctx->mb_width  = FFALIGN(avctx->width,  16) >> 4;
     ctx->mb_height = FFALIGN(avctx->height, 16) >> 4;
 
-    ctx->num_x_slices = 16;
-    ctx->slice_width  = ctx->mb_width / 16;
+    ctx->num_x_slices = (ctx->mb_width + 15) >> 4;
+    ctx->slice_width  = 16;
     for (i = 1; i < 32; i++) {
         if (!(ctx->mb_width % i) && (ctx->mb_width / i < 32)) {
             ctx->slice_width  = ctx->mb_width / i;