While the previous method worked, it matches no other implementation including a reference implementation. The new implementation almost perfectly matches the reference implementation and uses oversampling to achieve the goal. This has the downside of limiting the blur size to just 64, but it is necessary in order to achieve correct results.
Fixes#573
There is hardly any reason for us to recalculate everything all the time. LUTs can cache the work once, and then re-use it every time necessary, drastically reducing the impact of Color Grading by almost 60% (on some GPUs even more). Additionally this fixes the negative gamma issue, which plagued the filter for a while.
In the future, once PR 4199 (https://github.com/obsproject/obs-studio/pull/4199) has been merged, we can cut away one intermediate rendering step currently required to make the effect work. Hopefully this will be with the 27.x release of OBS Studio.
For simple image and video editing, LUTs (Look-Up Tables) are vastly superior to running the entire editing operation on each pixel - especially if all the processing can be done inside a single shader.
Due to the post-processing requirements for our LUTs, we are limited to 8 bits per channel - though clever use of the unused Alpha channel may result in additional space. For our purposes however, this is definitely enough.
The new libOBS API allows us to directly access the underlying API instead of having to mess around in memory. By using it we can avoid crashing in case the compiler for it is different, or in case the actual back end structure changes.
Additionally the mostly unimplemented and unused options have also been removed, which streamlines the use of this class even further and reduces both shader and code complexity.
Finally by optimizing the use of the internal render target we can achieve a speed up of up to 3000% over the old way, allowing for many more mipmapped filters.
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This allows me to provide you with an automated zoom and cropping solution for your video camera to transform your streams into a slick, polished broadcast, where you’ll always be the star of the show. Don’t forget - everything is customizable so the possibilities are endless. You can even recreate that Futurama squinting meme if you wanted to (with some scripting)!
The filter requires compatible Nvidia RTX hardware and the Nvidia AR SDK Runtime to be installed ahead of time. This filter is considered "stable" and shouldn't change much from version to version.
This drastically improves stability and prevents all exceptions from leaking into libobs C code, which prevents crashes and unexpected freezes from exception handlers further down the stack.
Additionally minor work was done to further improve the quality and user experience for the filter.
Fixes the bug that rendering an outline would remove all other effects not directly under the outline, while also improving the rendering speed drastically by only initializing and clearing the rendertarget once instead of for each effect.
This filter allows the use of another source as a mask, allowing complex filter graphs and trippy effects, such as creating a text source with three animated videos, each using a different color channel as the mask.
Fixes#18.
This refactors the SDF Effects to use a normal blend function instead of doing the blend in the effect itself, improving quality and reducing problematic sampling issues. In addition to this, the effect files have been cleaned up slightly and renamed to their proper names. Glow and Stroke are now supported, which solves both #2 and #4 in one go.
The caching optimization has also now been implemented, reducing the number of renders for this filter to 1 for each tick.
Dual Filtering (or Dual Kawase) is an approximation of Gaussian Blur that can reach much higher Blur sizes at a much lower cost. However it is locked to a 2^n size, which means that currently it isn't possible to use it for blur sizes like 19, 24 and 31.
The Blur works by using the linear sampling of a GPU, combined with down- and upsampling and carefully placed sampling points. This means that there is no need for a linear optimized version of this Blur.
Related: #45, #6
While Gaussian Blur is not a Blur type that really benefits much from linear sampling, it can be used for a slight quality and gpu usage reduction. However for Area and Directional Blur there is a better alternative: Dual Filtering Blur. And as with all other currently implement Linear versions of Blur, only Area and Directional Blur are supported.
This type of Gaussian Blur also has the loading hitch that exists in normal Gaussian Blur.
Related: #45, #6
Gaussian Blur is another Blur that now supports the new system, increasing the maxium Blur size to 128 and adding support for Rotational and Zoom blur. Various optimizations were done to the actual shader code which further reduced the GPU usage.
Currently the Gaussian curve is recalculated when the blur is first created, which can lead to a short hitch due to it having to search for the correct kernels. This is currently unavoidable and expected behavior until a better solution is found.
Related: #45, #6
Box Blur is a prime candidate for Linear optimizations, and as such reducing the total necessary samples by about half. However due to the reduction in samples, only Area and Directional Blur are supported.
Related: #45, #6
Box Blur is the first to be on the new system and has received all the new features and optimizations available. The maximum Blur size has been increased to 128, Rotational and Zoom Blur are supported and a small optimization has been done to the shader.
Related: #45, #6
Earlier versions tried using Trilinear as the Filter, but the correct name is Linear. With this the sampling is now set to be Linear instead of undetermined.
Additionally the logic for the displacement was adjusted and now no longer renders incorrectly when going from texel to texel. This was due to the unstable math being performed to retrieve the sign of the number, but the sign() command can do it without this math being required.
This works around the incorrect shadow on the edge of the Signed Distance Field, but it does not get rid of it completely. Due to linear sampling it will still show at some point so a different solution has to be found in the future.
Colored shadows previously had an effect on the image color, but this is incorrect if the image is fully opaque. This fixes it by using premultiplied alpha mixing instead.
Sources were rendering with a black border around them if they had a soft fade, which is due to how the shadow calculated the image sample. With the new shader code this is now fixed and the source looks like it should be. Additionally this removes the bug where enabling any shadow would cause only the texels to draw that were above the threshold.
Additionally this adds support for inverse gradients (min > max) and negative gradients for outer shadows instead of only positive gradients. This technically allows for cleaner shadows.
This speeds up Gaussian Blur and Linear Gaussian Blur drastically reduces time spent reading textures and instead uses existing registers - maximizing time spent reading the actual image texture.
See Also: #21 Blur Quality
Similar to Linear Box Blur, this version of Gaussian Blur reduces the total number of sample by up to n. This results in a total sample count (per pass) of O(n+1) for even radii and O(n+2) for odd radii. The quality sacrificed to do this is higher this time, though careful adjustment of the halfTexelDelta value can bring it much closer to normal Gaussian Blur. The current offset however had no noticable effects on visual quality.
See Also: #21 Blur Quality
Linear Box Blur abuses the fact that with Linear Sampling we can sample up to four adjacent texels at the same time and get a correct result for Box Blur back. Using this the total number of sample for Box Blur is reduced by n, making the total either n+1 (Even Radius) or n (Odd Radius).
Additionally all blur effect files have been merged into a single blur.effect file to reduce the time required to change a single parameter name. New blur effects should be added as a new technique instead of as a new effect file.
See Also: #21 Blur Quality
Adds Inner/Outer Shadows for dynamic sources based on signed distance field generation. This is fast, but does add a bit of latency when it comes to updates - which means that moving objects will leave a trail before the generator has a chance to update.
Fixes#3
* Removes the old 'Region' fields and places them under a 'Mask' option that can do much more.
* Supported Mask types: Region, Image, Source.
* Image and Source mask types allow for a color filter and multiplier.
* Supports region, feathered region, inverted region, inverted feathered region and image input.
* Interpolates between image_blur and image_orig depending on the result of the mask function.
This enables full mipmapping support for textures with a shader view that allows accessing different mip levels. In order to access mip levels, you have to specify gs::texture:🎏:BuildMipMaps when creating the texture, as OBS currently forces the maximum mip level to 1 even if you actually have mip data available.
The Blur Filter can now be applied to a region inside the source itself, the inverse of that region, and/or a feathered version of that region. This allows for easier scene setups where only some parts need to be blurred, but the rest can be left as is.
Fixes#12
End goal of this is to be an anisotropic filtering purely on the GPU without any actual mipmaps in the graphics subsystem. The basic idea behind it is that we can create all possible mipmaps in a twice as big texture as the original and then can efficiently render it no matter the GPU features as it will only consume one sampler.
The texture that it outputs will have both horizontal, vertical and full mipmaps in it. Horizontal mipmaps reduce Width, Vertical mipmaps reduce Height and full mipmaps reduce both. This means that LoD levels are both possible in the X and Y direction, allowing for much greater precision mipmapping on all GPUs.
This is a temporary solution until we can directly copy updated textures to a mipmap level.
Michael Fabian 'Xaymar' Dirks