Answers.Body: <p>By default, ffmpeg treats image sequence and raw video inputs as having a native rate of 25 fps unless told otherwise. So, the <code>-r 50</code> duplicates each frame.</p>
  
  <p>Use</p>
  
  <pre><code>ffmpeg -framerate 50 -i imageSeq-%06d.png -vcodec png -pix_fmt rgb32 -y video.mov
  </code></pre>
  
  <p>You can skip the <code>-r 50</code> since ffmpeg will use the input's framerate.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-11-23T16:08:24.670Z
Answers.LastActivityDate: 2017-11-23T16:08:24.670Z
Answers.UserDisplayName: Gyan
Body: <p>I'm using ffmpeg to convert a <code>PNG</code> image sequence into a <code>.mov</code> file with alpha channel for use in my NLE.</p>
  <p>The <code>PNG</code> sequence was rendered out of DashWare where it was generated in sync with a 4m35s (approx) 1080p50 video clip.</p>
  <p>As expected the image sequence consisted of just over 13,750 images.</p>
  <p>I used the following command to convert these into the required <code>PNG</code> encoded, uncompressed <code>RGBA</code> (rgb32) <code>.mov</code> file.</p>
  <pre><code>ffmpeg -i imageSeq-%06d.png -vcodec png -r 50 -pix_fmt rgb32 -y video.mov
  </code></pre>
  <p>And the file converted OK <em>but</em> it's duration came out at 9m10s - exactly double what it should have been.</p>
  <p>By my reckoning 4m35s at 50fps is: <code>((4x60)+35)x50</code> which is 13750 frames/images. So why did the duration double in conversion with the above command?</p>
  
Tags: <ffmpeg><quicktime>
Title: ffmpeg **doubled** my duration
UserDisplayName: Fat Monk
ThreadText: # ffmpeg **doubled** my duration
  
  (Asked by: username_0 on 2017-11-23)
  
  I'm using ffmpeg to convert a `PNG` image sequence into a `.mov` file with alpha channel for use in my NLE.
  
  The `PNG` sequence was rendered out of DashWare where it was generated in sync with a 4m35s (approx) 1080p50 video clip.
  
  As expected the image sequence consisted of just over 13,750 images.
  
  I used the following command to convert these into the required `PNG` encoded, uncompressed `RGBA` (rgb32) `.mov` file.
  
  ```
  ffmpeg -i imageSeq-%06d.png -vcodec png -r 50 -pix_fmt rgb32 -y video.mov
  
  ```
  
  And the file converted OK *but* it's duration came out at 9m10s - exactly double what it should have been.
  
  By my reckoning 4m35s at 50fps is: `((4x60)+35)x50` which is 13750 frames/images. So why did the duration double in conversion with the above command?
  
  **Tags:** ffmpeg, quicktime
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2017-11-23. Score: 5 | Accepted answer
  
  By default, ffmpeg treats image sequence and raw video inputs as having a native rate of 25 fps unless told otherwise. So, the `-r 50` duplicates each frame.
  
  Use
  
  ```
  ffmpeg -framerate 50 -i imageSeq-%06d.png -vcodec png -pix_fmt rgb32 -y video.mov
  
  ```
  
  You can skip the `-r 50` since ffmpeg will use the input's framerate.
  
  
  ---
  
  