lavf/wavdec: skip padding byte

WAV chunks must be even aligned. This patch skip the extra padding byte
if chunk size is odd.

Fixes ticket #2417.

Reviewed-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/wavdec.c

@@ -74,7 +74,7 @@ static int64_t find_tag(AVIOContext *pb, uint32_t tag1)
         size = next_tag(pb, &tag);
         if (tag == tag1)
             break;
-        avio_skip(pb, size);
+        avio_skip(pb, size + (size & 1));
     }
     return size;
 }
@@ -354,6 +354,9 @@ static int wav_read_header(AVFormatContext *s)
             break;
         }
 
+        /* skip padding byte */
+        next_tag_ofs += (next_tag_ofs < INT64_MAX && next_tag_ofs & 1);
+
         /* seek to next tag unless we know that we'll run into EOF */
         if ((avio_size(pb) > 0 && next_tag_ofs >= avio_size(pb)) ||
             avio_seek(pb, next_tag_ofs, SEEK_SET) < 0) {