This article will cover the basics of the preset modifications available in the advanced preset settings. The similar Simple preset settings, which include Method, Frame Rate, Target Data Rate, Frame Size and Key Frames are all covered under the article titled MainConcept H.264 Preset Customization.
A notable feature in the x264 settings is the 1-Pass CQ (Constant Quality) encoding method.
This method will activate two Advanced settings that are otherwise disabled: Constant Rate Factor, and the CFR Max Checkbox. You will also notice that the Target Data rate will be disabled if this method is selected, as all quality will be determined by those two aforementioned settings.
Most of the advanced settings will give a brief description when hovered over with the mouse pointer. An explanation of the most pertinent settings will be described here for clarification. Other settings should be left at their default.
Constant Rate Factor
This is a percentage value between 0 and 100. A value of 0 will give you the highest quality and a value of 100 will give you the lowest.
Note: A factor of "0" will not play in QuickTime X (Mac)
Sets a floor for the quality reduction when using the Constant Rate Factor setting to determine the overall Quality.
This setting is the most convenient way to modify the advanced settings to determine the best quality for the output file. The preset settings range from Ultrafast to Very Slow and Placebo. In general, the slower the compression time, the greater the output quality, with perhaps exception at the slow end, where the slowest preset is appropriately named Placebo to reflect the fact that it is slowest of all, with a virtually unnoticeable difference in quality.
These are additional presets that are intended to create a specific 'look' to the output file.
If your source content matches one of the available tunings you can use this, otherwise leave this set to None. Here is a brief explanation of the different tuning settings:
- Film - Optimized for most non-animated video content (not only feature films).
- Animation - Optimized for animation. Note that most 3D animation behaves more like film and not like hand-drawn animation, so only use this for hand-drawn animation (anime, classic Disney, etc.).
- Grain - Optimized for film with high levels of grain.
- Still Image - There has been some demand for this from companies looking to use x264 for still image compression (it can outperform JPEG or JPEG-2000 by a factor of 2 or more).
- PSNR - The phrase peak signal-to-noise ratio is an engineering term for the ratio between the maximum possible power of a signal and the power of corrupting noise that affects the fidelity of its representation.
- SSIM - uses "structural similarity" to optimize video quality. It is designed to improve on traditional methods like PSNR, which have been suggested to be inconsistent with human eye perception.
There rest of the advanced settings have definitions that can be found either by hovering over the setting or in the MCH.264 Preset Customization page.