this bitrate viewer calculate vfr videos in cfr way

[Tf-cheiya]

bitrate mbps should be based on seconds, not frames. get the current_second from pkt_pts_time or pkt_dts_time instead of (frame_count/fps)

def __calculate_bitrate_per_sec(self, bitrates):
    seconds = []
    bitrates_per_sec = []
    current_second = 0
    current_bitrate = 0
    frame_count = 0

    for bitrate in bitrates:
        current_bitrate += bitrate
        frame_count += 1  <===================================

        if frame_count == self.__fps: <===================================
            seconds.append(current_second)
            bitrates_per_sec.append(current_bitrate / 1_000_000)  # megabit
            current_bitrate = 0
            frame_count = 0
            current_second += 1

    return seconds, bitrates_per_sec