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Video formats are a confusing mess. Fortunately there are a couple of ways that you can often get downloaded videos to play without too much fuss.

I receive video attachments from several reliable friends, however, I am unable to open most of them, saying my media player does not support the .cda, .vob, etc. What can I do to change this so I can view some of these?

As I've stated in an earlier article, video playback in Windows is a mess. It really is.

The problem is there are so many formats and players that it's difficult to figure out what to do if your player can't play a particular format.

Even I'm not going to be able to give you a straight answer. But I do have some clues that may help point you in the right direction.

What you're missing is a "codec", or coder/decoder for those particular formats. The media player you're using, be it Windows Media Player, Quicktime, Winamp, or something else entirely, doesn't actually know about formats - it just knows how to find the right codec for the right format. Many media players will even automatically connect to the internet and look for known codecs online automatically. If it can't find the right codec, then it can't play the file.

Locating and safely installing a specific codec is not an easy task for the average consumer. Heck, it's not an easy task for many computer geeks.

Take your ".vob" file, for example. Using a file extension resource on the web, VOB appears to be a DVD video file. In my experience they're quite literally the files of information containing the movies on video DVDs.

But a codec? That's a little harder to come by. Particularly since at least one site warns against downloading and installing random codecs as they're apparently a popular place for viruses and spyware to be placed.

"Locating and safely installing a specific codec is not an easy task for the average consumer."

One solution for VOB files has been to use commercial DVD player software. Even if you don't have a DVD drive, a DVD player program will often come with the codecs necessary to play the files from other places, such as your hard disk. For example I believe that Power DVD, which came pre-installed on my Dell laptop, does this.

Another solution is the VideoLan VLC Media Player. This free software supports a wide variety of file formats, including VOB. In fact I've had folks tell me that they've rarely come across a format the VLC couldn't play.

CDA files are a different matter.

According to that same file extension resource, cda files don't actually contain the audio. They're a file created by Windows to make a CD audio disc "look like" it has files. Apparently if you copy the CDA file and email it to a friend, you've not actually emailed anything useful.

The right way to get audio off of a CD is to use ripping software such as the free program CDex. CDex will copy the audio from a normal audio CD and create MP3 files, which can be played almost anywhere.

Article C3079 - July 9, 2007 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

George Arauz
July 9, 2007 5:06 PM

Usually has programs you can download for free to read all types of video formats. Try that.

Greg Harvey
July 9, 2007 6:20 PM

GOM player- It is the best. If you don't have the correct codec, it will direct you to the web page to down load it.

Hairol Sibaja
July 13, 2007 7:16 PM

Tell him to Download K-lite codes pack if will be what he need.

July 13, 2007 7:17 PM

I'm just curious, Leo, as to whether or not you've tried K-lite
It's a simple, free single file to download and install, which then makes heaps of codecs available to WMP, or even has a basic media player of its own like the old Win98 one.
I've been passing this file on to non-tech friends for ages, and they all manage to do it without too many questions. The Standard Pack is usually pretty all-encompassing of the codecs people need.

Terry Hollett
July 14, 2007 6:34 AM

To identify codecs try this free program

Terry Hollett
July 14, 2007 6:39 AM

Sorry, I should make it clearer. If you have trouble playing a movie and your media player has trouble finding codecs. Use Gspot to examine the clip (it can determine the codecs necessary) and then use your choice of search engin to find that codec or use the above mentioned codec packs.

Trudy Light
July 16, 2007 9:28 PM

How do I find out what codec it is when Gspot codec utility doesn't recognize it?

Rakesh Biswas
February 25, 2009 1:20 AM

How can I play VOB file in VISTA media player.
I copy a VOB file in my Desktop but it dosnt play. When I insert DVD disk it Play but copy VOB file dose not play.

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