'Quality' meaning in codec?

What exactly does “Quality” mean? If I have the resolution & fps set at a certain level will adjusting the quality have an effect? Or is it just for colors & stuff?

“High visual quality” means the exported video looks just as good as the original footage. “Low visual quality” means smearing, duller colors, loss of detail, and sometimes blockiness.

There is a tradeoff between visual quality, file size, and processing time. Usually, the higher the quality goes, the larger the file size gets… unless you’re willing to burn a lot of processing time trying to keep the file size down.

Hi,

Quality mean compression with loss. It’s similar to Jpeg quality but for some code the compression is not for one frame but also between multiple frames. A low quality mean a lighter file but also mean more artefact and blur.

True, but that is controlled by the GOP parameter, not the Quality parameter. I only mention that to avoid confusing the OP, since the question was about the Quality parameter.

If you are interested in details, for your particular screenshot quality means the CRF value (it’s rather complicated to explain exactly what it means but there are long articles if you want to get in depth). In short it tells the program how many details to keep or to lose in order to make a bigger or smaller file (but it’s not really this simple).

If you are more familiar with bitrate, you can change Rate control to variable bitrate mode and just input a number of megabits per second instead.

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Thanks for the response… So, adjusting the ‘quality’ will have an effect on the fps & resolution, correct?

adjusting the ‘quality’ will have an effect on the fps & resolution, correct?

FPS and resolution are fixed parameters. They don’t change in response to anything else. They stay at whatever you set them to be.

The Quality parameter determines how detailed your resolution will look. This is the difference between “resolution” and “definition” of an image. If the quality is set too low, a video with 4K resolution can have the visual definition of 720p due to all the details lost during compression. Even though the video looks low quality, the resolution and FPS stayed the same (4K in this example). It would be like taking a high-resolution picture of an out-of-focus subject. You have a bunch of pixels, but they all mush into each other instead of being crisp. So, if you want high quality, the challenge is to find a resolution/quality pair that allows each pixel to have a crisp definition. (That is an abstract concept, not an actual objective to achieve. Visual quality is a little more nuanced than that.)

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Just for fun, here’s an example of the difference between Quality set to 10%, 20%, 30%, 40%, 55% and 100%

You’ll notice that, visually, there is almost no difference between 55% and 100%.

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For me the codec at default is at 55% but when I Export a video at higher percentages, I get a REALLY LARGE file. Is this because at a certain high percentage exporting with codec at a higher quality creates unnecessary clarity? Like exporting a 30fps video in 60 fps, just double the frames but it all looks the same for the most part.

nvm I just saw this

Are you doing this because 55% didn’t look good enough? “Perfect” will always be a large file. Final export is usually about finding a happy “good enough”, and your eyes are your guide.

Yes, basically. The codec is faithfully preserving details so subtle that your eye can’t even detect them. The human eye is actually not very sensitive to color data compared to luminance. This is why encoders can throw away a lot of data and the final image still looks pretty good. The eye isn’t sensitive enough to notice anything is missing.

Correct, this would not improve anything visually, and would waste space. Twice as many I-frames would be needed if the GOP wasn’t doubled to compensate.

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