Missing QuickTime codecs

This content is 17 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Earlier this week, I needed to play back a .AVI file in iTunes/Front Row. That’s not really a problem as it’s easy to convert the video to a .MOV file using Apple QuickTime Pro but one major issue was a complete lack of sound.

Now, before I go any further I should explain that there is one common theme throughout the comments section of every site discussing media formats and players – someone always says something to the effect of “use VLC – it plays everything”. VLC is a great media player but:

  • I have Apple QuickTime Pro.
  • I use Apple iTunes and Front Row (both of which depend on QuickTime).
  • QuickTime components are available for many audio and video formats.

In other words, using VLC isn’t the right solution for me. QuickTime gave me a clue as to the problem as it informed me that:

Some necessary QuickTime software is missing. It may be available on the QuickTime Web site.
If you have a dialup connection to the internet, make sure it is active, then click the Continue button to check for the software.

I could have worked out for myself that I was missing a codec (and that message is pretty poorly written… should I not click continue if I don’t have a dialup connection? Maybe I’m reading the message too literally!) but clicking continue took me to the QuickTime components page and I didn’t know which one I needed. I was pretty sure that the video was an XviD movie and I already had the DivX codec (v6.4) as well as Christoph Nägeli’s XviD codec (v0.51) installed but then I found a big clue in the XviD FAQ:

It’s important to understand that video and audio are two separate things, which when combined make up movies. A movie consists of a video stream for the picture and an audio stream for the sound. The XviD codec is what makes it possible to decode the video stream, but it has nothing to do with decoding the audio stream. If the sound in a movie isn’t working you have to find out which audio codec is missing and install it.

The FAQ continues to explain how to use a Windows utility called GSpot to identify the necessary codecs but after reading Mike Peck’s article about playing XviD movies on an Intel Mac (and Paul Stamatiou’s follow-up post on getting Front Row to play XviD, DivX and 3ivX videos), I realised that the missing codec was for AC-3 (Dolby Digital). After installing the A52Codec (v1.7.2) for AC-3 playback and restarting QuickTime and iTunes I was able to watch my video, complete with the previously-missing audio stream.

I’m sure that over time I’ll need to add more codecs and one potentially useful resource is afreeCodec , offering downloads for Windows, Linux and Macintosh computers, games consoles and mobile phones.

8 thoughts on “Missing QuickTime codecs

  1. Installed a52, AC3, and I still am missing video and sound.
    It seems really stupid that Quicktime works so well on a PC, but here I got an iMac and it only works sometimes for some vids. How stupid is that Steve Jobs?

  2. right, i am being driven insane by too much advice, none of which is solving my problem. i have full res quicktime .mov files off a mac. they do not play video (only sound) on my vista pc. note that the compressed versions played just fine.

    i am getting a message saying a quicktime codec is missing. i have downloaded a bunch of apps, none of which has done anything to find or install this missing codec and as you know quicktime’s site is crap.

    what i need is to find this missing codec so firstly, i can view my videos.

    secondly i will need to be able to compress and upload to various sites.

    if you can at least solve the codec issue i’d appreciate it.

  3. @MS – GSpot (linked in the original post above) will tell you what codecs your video requires. Tracking them down and installing them on Vista is another issue but at least you will know what you are looking for.

  4. Mark, you sir are a genius. I was having the same difficulties and followed your instruction…and now have sound to go with picture.


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