libavcodec/vorbis_dec.c:1615: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned64 by call to `vorbis_parse_audio_packet`.

libavcodec/vorbis_dec.c:1615:11: Call
1613.     init_get_bits(gb, buf, buf_size*8);
1614. 
1615.     len = vorbis_parse_audio_packet(vc);
                ^
1616. 
1617.     if (len <= 0) {

libavcodec/vorbis_dec.c:1451:1: <LHS trace>
1449. // Decode the audio packet using the functions above
1450. 
1451. static int vorbis_parse_audio_packet(vorbis_context *vc)
      ^
1452. {
1453.     GetBitContext *gb = &vc->gb;

libavcodec/vorbis_dec.c:1451:1: Parameter `vc->mappings->coupling_steps`
  1449. // Decode the audio packet using the functions above
  1450. 
  1451. static int vorbis_parse_audio_packet(vorbis_context *vc)
        ^
  1452. {
  1453.     GetBitContext *gb = &vc->gb;

libavcodec/vorbis_dec.c:1548:10: Binary operation: ([0, +oo] - 1):unsigned64 by call to `vorbis_parse_audio_packet` 
  1546. // Inverse coupling
  1547. 
  1548.     for (i = mapping->coupling_steps - 1; i >= 0; --i) { //warning: i has to be signed
                 ^
  1549.         float *mag, *ang;
  1550. 
