Video Codecs Compressions Extensions
Codecs Compressions Extensions is the maze for many motion picture/video/film media makers.It’s no wonder because most of these people are arty creative minds and codecs and compressions are far from this.These are among the necessary bad things for creatives.
This guide might help you to understand video codecs compressions extensions formats better.Easy to read in plain English.
Many people say : This is a process that degrades quality.
It’s technically true but practically not.Why? – you might ask.
Before answering to “Why?” there is another question “What do yo need?” There are basically 2 kinds of usage 1. editing 2. delivery that’s why we can differentiate Editing formats and Delivery formats.
Editing formats are used for post-production where the possible highest quality is important.These are image sequences like .png, .tif, .exif etc.or embedded clips with animation, AppleProRes422 or 444 etc. codecs.These formats keep maximum image information (some lossless) and can be greatly used ie. for color grading, greenscreen keying.These files are huge and can be effectively used only in post-production. In this case of (non)-compressing, the higher the resolution (1080, 4K, 8K etc.) the larger the files will be because of their lossless characteristic.Ergo, you need a very strong computer to flawlessly handle these clips on your timeline in their native format and resolution.
Delivery formats are the ones that you can watch at home on your TV.This is mostly a .h264 codec in a .mp4 container (with a .mp4 file extension).These files are small but still with great quality.They can be used for editing but the quality difference will be easily seen in post-production as color grading and keying tasks require a lot more image information embedded.These files are optimized for broadcasting and watching.
Do you, as a watcher, see any difference between editing and delivery videos?
If the files are compressed fine you won’t see any difference.
If the files are heavily compressed you’ll see blocky images on high-detailed parts (such as forest shot, water, or blue sky shots can look ugly etc.) and also at faster camera movements.In these days broadcasters have enough bandwith to use better quality compression so the chance you see the difference is relatively low.
That’s why “Compression is a process that degrades quality.” is technically true but practically not.It can be rather composed that “Compression is a process that reduces file size and try to keep the best possible quality so that the files can be effectively used.”
Codecs define the quality of the compression therefore they have huge impact on the file size.
Some popular EDITING codecs :
– .png image sequences
– .tif image sequences
– .exif image sequences (this is rather popular in high-budget productions)
Embedded codecs (after export you get one playable video file instead of individual images of each frames (image sequences))
– DNxHR and DNxHD
– PhotoJPEG (this is a codec somewhere between editing and delivery)
Basically the best DELIVERY codec :
– .h264 (don’t know much about .h265 but I know that .h264 works just perfect)
I’ve heard from couple of people that if you need ie. AppleProRes422 but you used a camera that shoots with .h264 codec you can just simply upconvert it and you’re done.That’s true up tp the point that you’ll have a huge AppleProRes422 (.mov) file but this file has the same image information as the original file.Basically there is no gain at all instead you fill up your HDD/SSD much faster.This way is a no go.If you need better quality you have to shoot at better quality.It’s easy as that.
The container is which the codecs are stored in.Extensions are the file types that can be .mov (QuickTime) | .avi (Windows) | .mp4 etc. but these are probably the most popular ones.
Just a super easy example :
Think of it as you have ie. pears (codec) and you put them into your basket (container).If you have many pears you need a big basket which isn’t easy to deliver but easy to edit them (because you have a lot of pears).
If you want to deliver them you need to pack them to smaller baskets.The only way you can do it in the most effective way is that you select only the nicest pears and put only those ones for delivery. Then you get smaller baskets with beautiful pears only but you cannot really edit them anymore except if you sacrifice beautiful apples.
Obviously this isn’t a scientific example of Codecs Compressions Extensions 🙂 but I guess it helps you to understand the basic concept better.