title: Concatenate all .mp4 files in a folder using ffmpeg
body: <p>I'm using ffmpeg to resize a bunch of videos and save them as: 1.mp4, 2.mp4, 3.mp4... in the same folder.</p>
  <p>Next, I'd like to use another ffmpeg command to concatenate all the videos in order, and save the final video in the same folder.</p>
  <p><strong>What I've Tried:</strong></p>
  <p><code>run('ffmpeg -f concat -safe 0 -i &quot;{}&quot; -c copy &quot;{}\\{}.mp4&quot;'.format(clips, location, today))</code></p>
  <p>where 'clips' is a txt file containing absolute paths to each clip, formatted as &quot;file path/to/file.mp4&quot;, location is the absolute path of the output directory, and 'today' is the file name such as '22 December'.</p>
  <p><strong>The Issue I'm Encountering:</strong></p>
  <pre><code>[concat @ 000001850996df80] Impossible to open 'D:Reddit'
  D:\Reddit Compilation Bot\Videos\Perfectly Cut Screams\22 December\paths.txt: No such file or directory
  </code></pre>
  <p>And yes, I've checked all my file paths to see if they were missing the backslash as the error suggests, but I couldn't find any issues. Further, I copied and pasted the path in the error message directory into  Windows Run and it opened without issue.</p>
  <p>What's going on here?</p>