dca: replace some memcpy by AV_COPY128

Signed-off-by: Janne Grunau <janne-libav@jannau.net>

libavcodec/dcadec.c

@@ -1241,9 +1241,7 @@ static int dca_subsubframe(DCAContext *s, int base_channel, int block_index)
     /* Backup predictor history for adpcm */
     for (k = base_channel; k < s->prim_channels; k++)
         for (l = 0; l < s->vq_start_subband[k]; l++)
-            memcpy(s->subband_samples_hist[k][l],
-                   &subband_samples[k][l][4],
-                   4 * sizeof(subband_samples[0][0][0]));
+            AV_COPY128(s->subband_samples_hist[k][l], &subband_samples[k][l][4]);
 
     return 0;
 }