libavcodec/ac3dec.c:1331: error: Buffer Overrun L1
  Offset: 4 Size: 2 by call to `ff_ac3dsp_downmix`.

libavcodec/ac3dec.c:977:1: Parameter `s->downmix_coeffs[*]`
975.  * Decode a single audio block from the AC-3 bitstream.
976.  */
977. static int decode_audio_block(AC3DecodeContext *s, int blk)
     ^
978. {
979.     int fbw_channels = s->fbw_channels;

libavcodec/ac3dec.c:1331:13: Call
1329. 
1330.         if (downmix_output) {
1331.             ff_ac3dsp_downmix(&s->ac3dsp, s->outptr, s->downmix_coeffs,
                  ^
1332.                               s->out_channels, s->fbw_channels, 256);
1333.         }

libavcodec/ac3dsp.c:253:1: <Length trace>
251. }
252. 
253. void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix,
     ^
254.                        int out_ch, int in_ch, int len)
255. {

libavcodec/ac3dsp.c:253:1: Parameter `**matrix`
  251. }
  252. 
  253. void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix,
       ^
  254.                        int out_ch, int in_ch, int len)
  255. {

libavcodec/ac3dsp.c:265:34: Array access: Offset: 4 Size: 2 by call to `ff_ac3dsp_downmix` 
  263.         if (in_ch == 5 && out_ch == 2 &&
  264.             !(matrix_cmp[1][0] | matrix_cmp[0][2]   |
  265.               matrix_cmp[1][3] | matrix_cmp[0][4]   |
                                        ^
  266.              (matrix_cmp[0][1] ^ matrix_cmp[1][1]) |
  267.              (matrix_cmp[0][0] ^ matrix_cmp[1][2]))) {
