ffmpeg流复制输出错误的帧速率

运行以下命令时,out.mp4的帧速率为30.10,即使video.mp4是30.00。我注意到out.mp4的持续时间应该是00:00:06.39,而不是00:00:06.38。我还看到,在out.mp4的ffprobe输出中,“start”参数是0.020000,而它应该(也许)是0.000000,我如何解决这个问题?我认为这种差异可能是由于我剪切的帧不是关键帧,但我真的不确定发生了什么:\

ffmpeg -i video.mp4 -ss 22 -c copy out.mp4

视频的ffprobe.mp4

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2mp41
    encoder         : Lavf59.20.100
  Duration: 00:00:28.39, start: 0.000000, bitrate: 2231 kb/s
  Stream #0:0[0x1](und): Video: hevc (Main) (hev1 / 0x31766568), yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 2100 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 125 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]

out.mp4的ffprobe

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'out.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2mp41
    encoder         : Lavf59.20.100
  Duration: 00:00:06.38, start: 0.020000, bitrate: 2307 kb/s
  Stream #0:0[0x1](und): Video: hevc (Main) (hev1 / 0x31766568), yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 2254 kb/s, 30.10 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]