title: How to combine a .MP4 video with a .WAV audio to create a new .MP4 video using ffmpeg from command line arguments?
body: <p>I want to merge a .WAV audio file with a .MP4 video file to create a new .MP4 video file.</p>
  
  <p>And i am currently using the following codes to do that :</p>
  
  <pre><code>ffmpeg -i input_vid.mp4 -i input_audio.wav -vcodec copy -acodec copy output.mp4
  </code></pre>
  
  <p>But it is only creating output.mp4 file but no videos embedded with that means if i am playing that output.mp4 file then nothing is playing.
  And i don't know where i am doing wrong so that it is creating like this.  </p>
  
  <p>I know this type of questions already asked by may persons but that didn't help me much so if anybody can find where i am doing wrong or how to solve this problem please help me to solve my problem.</p>