title: ffmpeg - Adding and Removing Subtitles without Changing the Video
body: <p>I'm trying to embed subtitles into video and removing the subtitles back again without changing the video, meaning I want the output video to be the same with the original video.</p>
  
  <p>I'm using the following command to embed the subtitles</p>
  
  <pre><code>ffmpeg -i original.mp4 -i original.srt \
  -c:v copy -c:a copy -c:s mov_text \
  -map_metadata 0:g -map_metadata:s:v 0:s:v -map_metadata:s:a 0:s:a \
  -movflags +faststart -threads 8 \
  output.mp4
  </code></pre>
  
  <p>To remove the subtitles, </p>
  
  <pre><code>ffmpeg -i output.mp4 \
  -c:v copy -c:a copy \
  -map_metadata 0:g -map_metadata:s:v 0:s:v -map_metadata:s:a 0:s:a \
  -movflags +faststart -threads 8 \
  -sn \
  removed.mp4
  </code></pre>
  
  <p>The output is almost the same but I couldn't figure out what would cause the difference. When I compare the binaries, almost all of the differences are </p>
  
  <pre><code>original: 0xF3
  removed: 0xF4
  </code></pre>
  
  <p>The bytes are incremented by 1, I think only in the header.</p>
  
  <p>Can you help? Thank you in advance.</p>