Combine Audio and Video with ffmpeg

By  on  

We have audio.  We have video.  We appreciate each of those media on their own but you can create an awesome work of art if you combine the two.  After all, how could you watch a sports highlight video without setting the visuals to some obscure techno track?  Blasphemy.

My favorite A/V utility, ffmpeg, allows you to merge an audio file and a video file into one brilliant piece of art:

ffmpeg -i video.mp4 -i audio.m4a -c:v copy -c:a copy output.mp4

You can even use an animated GIF for the video piece:

ffmpeg -i video.gif -i audio.m4a -c:v copy -c:a copy output.mp4

Banter aside, there are many good cases for combining an audio track with a video track, many examples being seen on YouTube.  Happy media creation!

Recent Features

  • By
    How to Create a Twitter Card

    One of my favorite social APIs was the Open Graph API adopted by Facebook.  Adding just a few META tags to each page allowed links to my article to be styled and presented the way I wanted them to, giving me a bit of control...

  • By
    Serving Fonts from CDN

    For maximum performance, we all know we must put our assets on CDN (another domain).  Along with those assets are custom web fonts.  Unfortunately custom web fonts via CDN (or any cross-domain font request) don't work in Firefox or Internet Explorer (correctly so, by spec) though...

Incredible Demos

  • By
    Vibration API

    Many of the new APIs provided to us by browser vendors are more targeted toward the mobile user than the desktop user.  One of those simple APIs the Vibration API.  The Vibration API allows developers to direct the device, using JavaScript, to vibrate in...

  • By
    Highlight Table Rows, Columns, and Cells Using MooTools 1.2.3

    Row highlighting and individual cell highlighting in tables is pretty simple in every browser that supports :hover on all elements (basically everything except IE6). Column highlighting is a bit more difficult. Luckily MooTools 1.2.3 makes the process easy. The XHTML A normal table. The cells...

Discussion

  1. Antoni

    There is a Firefox extension for this if anybody prefers UI over command line, https://addons.mozilla.org/en-US/firefox/addon/media-converter-and-muxer

  2. If you don’t want to re-encode audio and video, you can use following command:

    ffmpeg -i video.mp4 -i audio.m4a -c:v copy -c:a copy output.mp4
    

    It will execute a lot faster.

    • Updated! Thank you!

    • Bumpledink Scrotleworth

      You can specify to copy both at once like this:

      ffmpeg -i video.mp4 -i audio.m4a -c copy output.mp4
    • This works like charm and looks few flags shorter too.

  3. Hi David,

    Nice article. Would these same commands work efficiently on android too?

    We have a mute video to which we hope to add audio recorded from phone.

    Any guidance would be great.

  4. JC

    Can’t find ffmpeg in a zip file. Any other similar tool that opens in Windows?

  5. Kevin

    I’m not a programmer so I’m sort of confused and frustrated at what I’m looking at. I have no idea how to use this lol

  6. howard Johnson

    Here is an example batch file that you can drag the two files onto to do the joining, delete the two files and rename to the original. (drag by the mp4 file)

    @echo off 
    "C:\Program Files (x86)\ffmpeg\bin\ffmpeg.exe" -i %1 -i %2 -c:v copy -c:a copy d:\folder\output.mp4
    del %1
    del %2
    copy d:\folder\output.mp4 %1
    del d:\folder\output.mp4 
    pause
    
  7. Ravi Sharma

    where do we keep ffmpeg.exe file and that audio and video files to whom we merge.

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!