title: How to get ffmpeg to append to existing ouput file and not overwrite it?
body: <p>I am receiving an MPEG-TS Stream via UDP and saving the contents to a file using FFmpeg (using codec copy and mapping all streams). In cases where the stream stops, I would like to restart FFmpeg the moment it resumes and append to the existing file already written to.</p>
  
  <p>How can I configure FFmpeg to append to the file and not overwrite it when it starts again?</p>
  
  <p>The input and output containers are both MPEG-TS and the number of streams and codecs will be the same.</p>