Answers.Body: <p>You would crop the full width and half-height. Then use hstack to join them.</p>
  
  <pre><code>ffmpeg -i input.mp4 \
  -filter_complex "[0:v]crop=iw:ih/2:0:0 [left]; \
  [0:v]crop=iw:ih/2:0:ih/2[right]; \
  [left][right]hstack[outv]" \
  -map "[outv]" -map 0:a -c:a copy output_3dv.mp4
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-22T21:01:58.280Z
Answers.Text: I get this error:
  [AVFilterGraph @ 0x7fa2a2402b00] No such filter: ' '
  Error initializing complex filters.
  Invalid argument
  I assume there is a syntax error in there somewhere?
Answers.UserDisplayName: alphablender
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-23T04:21:06.953Z
Answers.Text: There was a trailing space in your original command (2nd line) which got copied over - removed it.
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-12T05:17:54.897Z
Answers.LastActivityDate: 2019-09-23T04:20:01.147Z
Answers.LastEditDate: 2019-09-23T04:20:01.147Z
Answers.UserDisplayName: Gyan
Body: <p>Based on the answer to <a href="https://video.stackexchange.com/questions/17131/convert-horizontal-side-by-side-to-vertically-stacked-3d-video?newreg=5ad754b5b60d46fc80546d15fb66b35c">this question</a>, how would the command line</p>
  
  <pre><code>ffmpeg -i input.mp4 \
  -filter_complex "[0:v]crop=in_w/2:in_h:0:0 [top]; \ 
  [0:v]crop=in_w/2:in_h:in_w/2:0[bottom]; \
  [top][bottom]vstack[outv]" \
  -map "[outv]" -map 0:a -c:a copy output_3dv.mp4
  </code></pre>
  
  <p>be changed to do the opposite, split two stacked images (3240x2160) to one 6840x1080 video?</p>
  
Tags: <ffmpeg>
Title: Convert Vertically Stacked video to horizontally stacked via FFMpeg
UserDisplayName: alphablender
ThreadText: # Convert Vertically Stacked video to horizontally stacked via FFMpeg
  
  (Asked by: username_0 on 2019-09-11)
  
  Based on the answer to [this question](https://video.stackexchange.com/questions/17131/convert-horizontal-side-by-side-to-vertically-stacked-3d-video?newreg=5ad754b5b60d46fc80546d15fb66b35c), how would the command line
  
  ```
  ffmpeg -i input.mp4 \
  -filter_complex "[0:v]crop=in_w/2:in_h:0:0 [top]; \ 
  [0:v]crop=in_w/2:in_h:in_w/2:0[bottom]; \
  [top][bottom]vstack[outv]" \
  -map "[outv]" -map 0:a -c:a copy output_3dv.mp4
  
  ```
  
  be changed to do the opposite, split two stacked images (3240x2160) to one 6840x1080 video?
  
  **Tags:** ffmpeg
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2019-09-12. Score: 1
  
  You would crop the full width and half-height. Then use hstack to join them.
  
  ```
  ffmpeg -i input.mp4 \
  -filter_complex "[0:v]crop=iw:ih/2:0:0 [left]; \
  [0:v]crop=iw:ih/2:0:ih/2[right]; \
  [left][right]hstack[outv]" \
  -map "[outv]" -map 0:a -c:a copy output_3dv.mp4
  
  ```
  
  > **Comments:**
  > **username_0**: I get this error: [AVFilterGraph @ 0x7fa2a2402b00] No such filter: ' ' Error initializing complex filters. Invalid argument I assume there is a syntax error in there somewhere?  
  > **username_1**: There was a trailing space in your original command (2nd line) which got copied over - removed it.  
  
  ---
  
  