Suggestions for CV article - video codecs

10 replies [Last post]
alan wells
Joined: Aug 13 2000

Video codecs - to a hobbyist, they are a maze!

Can someone point me in the right direction as to which to use, when and why?

Joined: Mar 6 2002

I am an Avid editor and find codecs a living nightmare (as apposed to a dead one I assume I mean...erm...) anyway, I deal with codecs everyday, going from Avid to After Effects 5.5 and back, streaming to the web etc.

I have endless problems with blank screens and colour washes mysteriously appearing all over my 5 hour render.

I have tried talking to Avid and Adobe about this but noone up to yet has provided me with an explanation.

Is there anyone out there who could compress and decompress the codec riddles for us??



Joined: Mar 19 2002

I don't really understand CODECs so I agree this would be a good article providing it is simple enough for the complete novice.

Joined: Apr 1 1999

Just be thankful that at least most of them fit in the QuickTime framework, or whatever MS call AVI these days. This allows many codecs to be interchanged fairly freely. An exception is MPEG since QuickTime doesn't support B Frames, and this is why the MPEG video file has to sit on a special track.

Each codec type needs a processing 'engine' that resides in the System. Some of these are supplied with QuickTime and are dual platform. Some are supplied with Windows and need to be downloaded separately for the Mac. Some are supplied only to support special hardware, although the codec is sometimes available alone such as those from Avid. Some are free to the viewer but expensive acquisitions for the authoring support. Sometimes (like Sorenson3 in QT) the extra cost pays for more sophisticated control but free basic authoring is provided.

Nearly all codecs use a similar approach for authoring with a choice of CBR or VBR, and a single or dual pass encoding process.

Joined: Feb 8 2002

Codecs are fun for many reasons. First of all, you have to try to encode your final AVI in a codec that most peoples' computers have installed, this inevitably means one of the older (less sophisticated) codecs. This reduces the quality from that which is desired.
When editing your video together, you have another set of problems. Until I get a capture card for my new pc (Athlon 1700XP with MSI nVidia 420 Mbd 256Mb DDR RAM [32 reserved for video], 40 GB hard drive - mobo has onboard GEForce 2 video, sound and LAN built myself for 767 euro inc case, cd and cooler) I am capturing on my partners pc, and having to recompress before transferring to my pc for editing. This is because the capture card is a Broadway, and uses a hardware based codec (as do many other capture cards).
Quicktime and Sorenson offer their own problems (resource hungry under windows).

Ron Spicer
Joined: Jul 22 2001

I don`t think the info flow is doing any justice to AMOSIB: B frames - processing engine - MPEG file has to sit on a special track - expensive aquisitions for the authoring support - a choice of CBR or VBR, and a single or dual pass encoding system........?

Bit like an explanation of navigation principles speaking of the LOP and Lat/Long - Sun GHA - Sun Total Correction Tables etc. Complete mystery to the uninitiated who wishes to know in a basic fashion.

Come on gents. Spill the beans in an understandable fashion for AMOSIB and then I`ll also have a better idea !

Cheers - Ron.

Joined: Oct 19 2000

I definitely agree with a review.
It's so frustrating that none of the codecs available even now with all the new products for editing and authoring on the market, offer what we really need, hig quality,fast encoding. It's this I think that causes us to have inferior output.
Lets have the lowdown

Ron Spicer
Joined: Jul 22 2001

And an everyday man`s way of explanation to satisfy the query in the original post. as well as quite a lot of people like me !


Tony Carter
Joined: Oct 15 2000

I hope the article will guide inexperienced people like me so that I will be able to understand all those codec's in Win98 (shown under control panel/multimedia/devices). Tony C.


Ron Spicer
Joined: Jul 22 2001

Yep - I`m waking up more to this one.

Reckon there should be a comprehensive article which includes a list of definitions (total) so that it could even be used as a reference point. All those short-form letterings which mean a lot to a few - explanations in full needed. Most of us know that codec is compression/decompression; but you try explaning to a child what is electricity ! Takes time and attention to detail.......

Cheers - Ron..

Joined: Aug 18 2000


If you're looking for a comparision of the common AVI codecs (including DivX and MJPEG), we've got this on our web site at:

If you want to know what a codec is and how it fits into the whole video editing thing, read:

If you're confused about the difference between codecs and drivers, we've got an article about that as well:

Hope this makes for enlightening reading!

Best regards,


Andy Dean, Pure Motion Ltd,

Andy Dean, Pure Motion Ltd,