Function ffmpeg_dev::sys::ff_compute_frame_duration

pub unsafe extern "C" fn ff_compute_frame_duration(
    s: *mut AVFormatContext, 
    pnum: *mut c_int, 
    pden: *mut c_int, 
    st: *mut AVStream, 
    pc: *mut AVCodecParserContext, 
    pkt: *mut AVPacket
)

Return the frame duration in seconds. Return 0 if not available.