函数 av_vorbis_parse_frame 

pub unsafe extern "C" fn av_vorbis_parse_frame(
    s: *mut AVVorbisParseContext,
    buf: *const u8,
    buf_size: c_int,
) -> c_int

Get the duration for a Vorbis packet.

@param s Vorbis parser context @param buf buffer containing a Vorbis frame @param buf_size size of the buffer