Answers.Body: <p><code>29.97</code> is shorthand for 30000/1001. There is no <code>29.970000...</code> frame rate standard. FFmpeg will keep the native framerate (usually), so no need to specify an output <code>-r</code> value.</p>
  
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Answers.CreationDate: 2017-05-31T07:20:04.357Z
Answers.Text: Thanks! So I can understand that the Sony Pro camera, in fact, shot at 30000/1001 fps.
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Body: <p>According to this <a href="https://ffmpeg.org/ffmpeg-utils.html#Video-rate" rel="nofollow noreferrer">ffmpeg documentation</a>, it seems one of the 'native' frame rate for <code>ffmpeg</code> is</p>
  
  <blockquote>
    <p>'ntsc':   30000/1001</p>
  </blockquote>
  
  <p>while 30000/1001=29.9700... does not equal to 29.97, I wonder if a Sony Pro camera really means it shots in 29.97, not 30000/1001?</p>
  
  <p>If that Sony camera does shot in exact 29.97fps, I suppose we should keep the 29.97fps, should not change the fps of the video file to 30000/1001?</p>
  
Tags: <ffmpeg><framerate>
Title: A Sony Pro camera's spec shows it shots in 29.97fps, does it really mean it?
UserDisplayName: shintaroid
ThreadText: # A Sony Pro camera's spec shows it shots in 29.97fps, does it really mean it?
  
  (Asked by: username_0 on 2017-05-31)
  
  According to this [ffmpeg documentation](https://ffmpeg.org/ffmpeg-utils.html#Video-rate), it seems one of the 'native' frame rate for `ffmpeg` is
  
  > 'ntsc': 30000/1001
  
  while 30000/1001=29.9700... does not equal to 29.97, I wonder if a Sony Pro camera really means it shots in 29.97, not 30000/1001?
  
  If that Sony camera does shot in exact 29.97fps, I suppose we should keep the 29.97fps, should not change the fps of the video file to 30000/1001?
  
  **Tags:** ffmpeg, framerate
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2017-05-31. Score: 3 | Accepted answer
  
  `29.97` is shorthand for 30000/1001. There is no `29.970000...` frame rate standard. FFmpeg will keep the native framerate (usually), so no need to specify an output `-r` value.
  
  > **Comments:**
  > **username_0**: Thanks! So I can understand that the Sony Pro camera, in fact, shot at 30000/1001 fps.  
  
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