bink: Bound check the quantization matrix.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit 9991298f2c)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/bink.c

@@ -677,6 +677,9 @@ static int read_dct_coeffs(GetBitContext *gb, int32_t block[64], const uint8_t *
         quant_idx = q;
     }
 
+    if (quant_idx >= 16)
+        return AVERROR_INVALIDDATA;
+
     quant = quant_matrices[quant_idx];
 
     block[0] = (block[0] * quant[0]) >> 11;