Mastering Video Codecs

Simply put, a video is like a flipbook made up of many still images.

The term “frame rate,” which frequently appears in video editing, refers to how many still images are displayed per second.
For example, a video with a resolution of “1920×1080” and a frame rate of “30fps” means that 30 still images of 1920×1080 pixels are shown every second.
That means a one-minute video would require “1,800” still images at 1920×1080 resolution.

If this enormous collection of still images were stored directly as video data, even a short clip would result in a file size of several gigabytes.
To solve this problem, a “codec” uses a compression algorithm to compress many still images into a video file using various methods.
By compressing the data, the file size of the video can be greatly reduced.

There are mainly two types of compression methods used by codecs.

1. Lossless Compression
Lossless compression is a method in which compressed data can be decoded (played back) and restored to exactly the same state as the original, without any loss in audio or image quality.
It reduces file size by efficiently organizing and compressing data within the file as much as possible.
Although the file size becomes smaller than uncompressed data, it is still significantly larger compared to lossy compression.
This method is excellent because it preserves the original data perfectly, but lossy compression codecs are generally easier to handle due to their smaller file sizes and greater versatility.

2. Lossy Compression
Lossy compression is a method in which compressed data cannot be perfectly restored to the original state when decoded (played back), resulting in some loss of audio or image quality.
It reduces file size by removing information that humans are unlikely to notice visually or audibly.
The higher the compression ratio, the more data is discarded, resulting in smaller file sizes but lower image and sound quality.

Among the many different types of video codecs, some representative examples are MPEG-1, MPEG-2, MPEG-4/AVC (H.264), DivX, and WMV.

The current mainstream codec is MPEG-4 AVC (H.264).
Although it may be referred to as MPEG-4, AVC, or H.264, they all refer to the same codec standard.
It provides high image quality with excellent compression efficiency, supports both low and high bitrates, and is widely used in Blu-ray discs and modern video cameras.

Among the many available codecs, one highly recommended option is :contentReference[oaicite:0]{index=0}.
It is a professional video format that allows broadcast-level footage to be edited on Mac systems with almost no quality degradation.
Compared to uncompressed files, it offers smaller file sizes while maintaining smooth performance and excellent responsiveness during editing.
Because it can achieve HD-quality video at relatively compact file sizes, it has been widely adopted throughout the video production industry.

Video editing usually involves moving projects repeatedly between different applications.
For example: color correction and rendering (exporting), applying special effects and rendering again, rearranging cuts and rendering once more, adding text and rendering again, and so on.
Since rendering is repeated many times during production, video quality can gradually deteriorate over time.
One major advantage of ProRes is that repeated rendering causes very little quality loss.

I also experienced situations in the past where repeated rendering caused the image quality to worsen each time.
At the time, I desperately searched for whether my encoding settings were incorrect.

In many professional workflows, editors first convert footage into ProRes format, edit in ProRes, and export again in ProRes.
Because the entire workflow can be completed consistently within the same format, ProRes has earned broad support in the industry.

First, download the preset for exporting in :contentReference[oaicite:0]{index=0} format from the following page.
Then, import the preset file (.epr) into :contentReference[oaicite:1]{index=1} to start using it.
AME CC 2014.1 ProRes presets (Mac only)

If you are using :contentReference[oaicite:2]{index=2}, you can export directly from Premiere itself.
However, when exporting multiple files at once, using Media Encoder is much more convenient.

When exporting a finished video project, the codec you should use depends on how the video will ultimately be used.
For example, uploading to YouTube, Facebook, Instagram, and other social media or video-sharing platforms may each require different file formats.

Video files are structured so that compressed video data is stored inside a format called a “container.”
Because of this, the first step is to choose the type of format (container) you want to use.

Here are some commonly used video formats (containers).

Next, select a preset that matches the intended use of your video.
If there is a preset that perfectly matches how you want to use the video, the remaining settings will be selected automatically.
If there is no suitable preset, you can configure the settings manually with custom options.

This is where you choose the compression format (codec).
If you select a format such as H.264 as the container format, the compression format may automatically be set to H.264 as well, making other codec options unavailable.

The screen size of a movie varies depending on its intended use.
The following are some commonly used resolutions.

Generally, a frame rate of 29.97 fps is commonly used.
If you plan to use frame rates such as 24 fps, it is better to consider the frame rate from the filming stage.

What did you think?
Even though we simply refer to them as “codecs,” there are actually many different types, along with a wide variety of related settings.
You do not need to memorize everything at once — it is best to start by learning the formats and settings that are necessary and commonly used in your own workflow.

Reference: Is Adobe Premiere Pro CC the Defacto Standard for Non-Linear Editing Software?

Reference: Converting to ProRes with Adobe Media Encoder CC

Reference: What Exactly Is QuickTime ProRes 422?