Dumbest Question in the world: Explain Codecs

J

jpastuch

Carbonite Member
I (think) understand, in vague terms, what a codec does. It basically translates all the little bits of the image and 1's and 0's into it's smoothest and best form while editing.

Am I half-right?

The thing is, I still don't understand what codec to use for what footage, where I get them, what I'm doing. Codecs aren't even MENTIONED in my editing class which uses FCP and I don't think any of my classmates even heard the word.

Worse yet, I figured my editor would know, he knows nothing about them.

But since I'm tired of seeing blocky, pixeleted designs on certain colors and digital noise in footage I know was lit correctly, here I am.

Berate me if you wish, but I'm not asking you to explain what is obviously a big subject that obviously WONT be the same in every instance. What do codecs do, in the most basic term, and what codec would suit me best for, let's say- a film shot on the DVX100 24pA and edited in FCP 6.0 be? How can I get my cleanest image and uh...use the codec in FCP?

(sorry again)
 
Codec is short for compressor/decompressor and the term describes the method (or algorithm) by which analog information is translated into and recorded as digital information and by which it is retranslated for playback. Codecs involves trade-offs involving quality and file size, and many camera manufacturers develop there own codecs in an effort to provide what they consider the best solution. Particular cameras will record in the codec or codecs that they are designed to record. The DVX100 records in DV NTSC because that is what it was manufactured to do, and that is what you would import into FCP. You could then transcode into a different codec if you had a reason to do so. (In some cases, you might need to transcode before importing into FCP where FCP doesn't support a particular codec, but I won't get into that.)

This is an enormous subject, and my knowledge is somewhat limited, but you are right to feel that it would be useful to you as an editor to have a working knowledge of the topic. For example, the codec you choose when you are moving between applications, such as taking footage from FCP to After Effects for effects work, can have a big effect on the quality of the final footage if you use the wrong codec (which in this case would be any codec that is not lossless). And clients or service bureaus will often want to receive files in particular formats for their purposes. I believe the FCP documentation includes some pretty good discussion of this subject. Here's the online link to the appendix on video formats: http://documentation.apple.com/en/finalcutpro/usermanual/index.html#chapter=B&section=0 That might be a good place to start in your efforts to educate yourself. Also, Apple just published a white paper on its new ProRes 4:4:4 codec in connection with the release of FCP 7, and that might be helpful after you have read some of the more basic material in the manuals.

Maybe others here with more knowledge than I on this topic will clarify or expand on the above or provide links to other sources of information. I think it is great that you are willing to wade into these technical details--they will only help you as an editor.

Hope that helps,
Kevin
 
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codecs

codecs

in the editing classes i teach, my students get tired of me talking about codecs, I mean it the raw materials you use to edit with. A basic to intermediate class that does not mention codecs is like taking an welding class with out learning metallurgy or a baking class with out knowing the differences in flours .....

when talking about editing files you have two components the file and the content of the file. the file type dictates how the operating system and software use the content. in editing this is usually the difference between AVi or Quicktime. AVI and Quicktimes are file structures that are desigend by the powers that be to contain audio and video information in a way that best suits their operating systems and software. The audio and video information with in these file structures must be encoded digitaly so the audio and video information can be stored as data. the same data be unencoded or de-encoded to be viewed. hence the term Codec. coded generally refers to the mathmatical algorythims used to arrancge the parts of the picture. Most codecs peerform some type of compression to make the data fit into a usable space. the terms compression and codecs are somtetimes used interchangbly.

it is important to seperate file type from compression type. the best analogy i have come up with so far is to imagine a book. You can have a book, "The Davinci Code" for example an have it in paper back or hard back or even tradeback. the stroy and the words would be the same in the book but how it is wrapped is different. this is like the quicktime and AVI difference. You can also have the book in hard back but in spanish and in english. This compares to compression. The story is the same, the wrapper is the same but some of the detail may change a little due to the differences in language. some languages are more efficient than others and some are more univesally. right now there are hundereds of codecs in the wild and each one has its own strength and weakness.

Some editing softwares like to make sure everything is in the same language before it can work. this is whay sometimes thing have to render before they can be used. My wife grew up speaking spanish and tells me her internal thoughts are in spanish which is her original language and sometimes when she tired the english i speak has to be translated for her to porcess in her head . most editing software require you to set up a project preset which essentilly does the same thing. it set up the mother language/ codec that the software processes in. when you dring a different codec into the editing process it will have to be translated so the software can process, encode, the information. modern softwares can translate on the fly elimating the need to render the files before they can be edited

I really could type more about this .... but i'll let some one else put in their 2 cents
 
Thanks guys...I did have a very basic idea of what they do. The thing that scares me is that there are so many of them. I guess I lot of it has to do with trial and error in your footage while editing?

Also, in case I missed it, is there a big topic discussing codecs in general? I know a lot of different codecs are discussed on here, but maybe some kind of quick stickie for people like me?
 
Really depends on your editing platform, complexity of color correction and final output. ProRes is good for FCP users. Color space is important in a codec, especially if doing green screen. Not sure about any stickies, but I am sure there are a lot of resources online for valuable information.

As for editing footage from the DVX. There isn't much information there - 720x480, 4:1:1 colorspace. Transcoding to another codec will not increase your resolution, only your file size (unless you add some kind of interpolation to the DV footage). Stick with DV unless you are doing greenscreen or multiple passes of color correction.

If you are unhappy with the footage from your camera, consider other alternatives. Even a cheap HD camera will give you a boost in resolution. The only way to get less grain and more dynamic range is by paying more (bigger chips and better technology will give you better results).


Jason
 
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