dnxhddec: check that the indicated bit depth matches the tables.

Fixes crash

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/dnxhddec.c

@@ -82,6 +82,10 @@ static int dnxhd_init_vlc(DNXHDContext *ctx, int cid)
             av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %d\n", cid);
             return -1;
         }
+        if (ff_dnxhd_cid_table[index].bit_depth != ctx->bit_depth) {
+            av_log(ctx->avctx, AV_LOG_ERROR, "bit depth mismatches %d %d\n", ff_dnxhd_cid_table[index].bit_depth, ctx->bit_depth);
+            return AVERROR_INVALIDDATA;
+        }
         ctx->cid_table = &ff_dnxhd_cid_table[index];
 
         ff_free_vlc(&ctx->ac_vlc);