Answers.Body: <p>Simply insert crop after the select filter.</p>
  <pre><code>-vf &quot;select=not(mod(n\,$N)),crop=1440:1080,tile=${COLS}x${ROWS}&quot;
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-06-23T23:50:22.143Z
Answers.Text: Thanks - I had tried that but my mistake was apparently that I was adding ":0:0" for the offset.  For some reason if I do that the crop does not apply in this context.
Answers.UserDisplayName: Pat Niemeyer
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-06-23T04:00:43.317Z
Answers.LastActivityDate: 2022-06-23T04:00:43.317Z
Answers.UserDisplayName: Gyan
Body: <p>I'm using the following to build a preview filmstrip image by grabbing every Nth frame and tiling them into a grid:</p>
  <pre><code>ffmpeg -i &quot;$file&quot; -frames 1 -vf &quot;select=not(mod(n\,$N)),tile=${COLS}x${ROWS}&quot; -y strip.jpg
  </code></pre>
  <p>However the input video has black bars so I'd like to crop them out before grabbing those frames using something like:</p>
  <pre><code>-filter:v &quot;crop=1440:1080&quot;
  </code></pre>
  <p>Adding that has no effect on the tiled output image.  I have also tried incorporating that filter into the -vf option to no effect.  Is there any way to accomplish this without a second pass that renders the whole video (temporarily) cropped?  Thanks!</p>
  
Tags: <ffmpeg>
Title: How can I apply a crop to frames before tiling with ffmpeg?
UserDisplayName: Pat Niemeyer
ThreadText: # How can I apply a crop to frames before tiling with ffmpeg?
  
  (Asked by: username_0 on 2022-06-22)
  
  I'm using the following to build a preview filmstrip image by grabbing every Nth frame and tiling them into a grid:
  
  ```
  ffmpeg -i "$file" -frames 1 -vf "select=not(mod(n\,$N)),tile=${COLS}x${ROWS}" -y strip.jpg
  
  ```
  
  However the input video has black bars so I'd like to crop them out before grabbing those frames using something like:
  
  ```
  -filter:v "crop=1440:1080"
  
  ```
  
  Adding that has no effect on the tiled output image. I have also tried incorporating that filter into the -vf option to no effect. Is there any way to accomplish this without a second pass that renders the whole video (temporarily) cropped? Thanks!
  
  **Tags:** ffmpeg
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-06-23. Score: 0 | Accepted answer
  
  Simply insert crop after the select filter.
  
  ```
  -vf "select=not(mod(n\,$N)),crop=1440:1080,tile=${COLS}x${ROWS}"
  
  ```
  
  > **Comments:**
  > **username_0**: Thanks - I had tried that but my mistake was apparently that I was adding ":0:0" for the offset.  For some reason if I do that the crop does not apply in this context.  
  
  ---
  
  