title: Add multiple timecodes to single audio file (.mkv ?) resulting from concatenating several (timecode-based) audio files
body: <p>I first converted two .WAV files into .MKV files inserting timecode for each of this file. Then I concatenated these two .MKV files as inputs (each .MKV including one <strong>timecode</strong> inside). However timecodes were not maintained in the final <em>output</em>.MKV. I tried:</p>
  
  <pre><code> 1. ffmpeg -f concat -i mylist.txt -c copy output.mkv  
   2. mkvmerge -o output.mkv 1.mkv + 2.mkv
  </code></pre>
  
  <p>with <code>mylist.txt</code> containing:</p>
  
  <pre><code>file '1.mkv'
  file '2.mkv'
  </code></pre>
  
  <p>But the final file <em>output.mkv</em> resulting from such a concatenation has lost <strong>timecodes</strong> in case 1. In case 2, there is only one <strong>time code</strong> that has been preserved (from input 2.mkv) at the end. According to <code>mediaInfo</code> command line. I was expecting 2 times codes issued from 1.mkv and from 2.mkv. But is it the right approach ? (Is it even do-able ?)</p>
  
  <p>To summarize, my goal is to insert multiple <strong>time codes</strong> along with / inside a single audio file (.WAV, or .MKV, or whatever). Here is a sreenshot that technically depicts my purpose <a href="https://i.stack.imgur.com/Z0lJc.png" rel="nofollow noreferrer">enter image description here</a></p>