libavcodec/mpeg2_metadata_bsf.c:157: error: Uninitialized Value
  The value read from ext_n was never initialized.

libavcodec/mpeg2_metadata_bsf.c:157:9: 
155.     found_frame_rate:
156.         sh->frame_rate_code        = code;
157.         se->frame_rate_extension_n = ext_n - 1;
             ^
158.         se->frame_rate_extension_d = ext_d - 1;
159.     }
