A few weeks ago, I added a new option to DVD Catalyst 4 called CRF. Since then, I have been suggesting this setting to quite a few people in order to get the best possible quality video conversions. This article explains in detail what CRF actually is, how it works, and why you should (and for some scenarions, why you should not) use it for your conversions.

Below a small portion of the CRF article. Because it is loaded with screenshots highlighting the differences between video conversions done with and without CRF, posting it fully here would result into a 10-post thread of its own.
You can find the full article here:

What is CRF? | Tools4Movies | DVD Catalyst 4

which makes it a bit easier to read.



What is CRF and why do I want to use it?

Previously, when encoding a video you had to decide what bitrate you wanted to use for your conversion, or adjust your quality based on what file size you want your video file to end up with. DVD Catalyst 4 does this by default, however there is now a third option: CRF.

CRF stands for Constant Rate Factor. It assigns a numerical value to a visual quality. The lower the number, the better looking the video will be. With a fixed quality or file-size setting, the visual quality of a video file is affected by the scene activity in the actual movie.
For fast-moving scenes, the visual quality is often less when compared to a slower-moving scene converted using the same settings. With CRF, the quality setting (bitrate) is automatically adjusted for whatever is needed for different activity in a movie, rather than forcing you to use a high-quality setting (and thus a larger file-size), which in many cases is just a waste of space.

How do you know what number is right for you? Visual quality is in the eye of the beholder. For some people, the quality needs to be identical to that of your original video, regardless of the file-size they end up with, for others, they just want to watch a movie and don't need to have it perfect, as long as they get to watch it.

By adjusting the numerical value used in CRF-enabled conversions, you can optimize your video files based on your own needs. If you want mint/pristine video files or good looking small-sized videos, or anything in between, it is all possible.

How do you know what CRF number is right for you? Read on and everything will be explained. From how to turn it on, differences in visual quality as well as how it affects conversion speed and file-size for the created video files.

How to enable CRF

Before you get started with CRF, you have to enable it in DVD Catalyst 4 first.

At the bottom right in DVD Catalyst 4, next to the Facebook and Google+ buttons is a checkmark "Power User". This setting nables access to all the power-features of DVD Catalyst 4. Enable this setting.

Then go into the "Global Settings" area (button on the top left), which will open up a collection of tabs controlling different aspects of your conversions with DVD Catalyst 4. In here, look for the "Tweaks" tab, and select it.

Under the “tweaks” tab, place a tick box next to the CRF option, as seen in the screenshot below.



Once that is done, you can press the “hide settings” button.

In the screenshot above you might have noticed that I selected an HQXT profile. CRF works best with these profiles and you will get the best quality vs file size when using them. If your device has an HQXT profile, you should be using it.

The HQXT profiles in DVD Catalyst 4 convert slightly slower than their normal counterparts, however, it makes up for the speed by using more powerful conversion settings resulting in better quality at a reasonable filesize. Combined with CRF, the visual quality of the video files created by DVD Catalyst 4 is significantly better than what you can achieve with other conversion tools, and at smaller filesizes as well.



The rest of this article continues here:

What is CRF? | Tools4Movies | DVD Catalyst 4