This repo contains user shaders for prescaling in mpv.

For the scripts generating these user shaders, check the source branch.

Shaders in gather/ directory and compute/ directory are generally faster but requires recent version of OpenGL. Use these shaders only if they actually work (i.e. no blue screen and no noticeable distortion).

Shaders in vulkan/ directory are using rgba16hf LUT, and required by gpu-api=vulkan and gpu-api=d3d11. Use these shaders if you encountered the following error:

[vo/gpu] Unrecognized/unavailable FORMAT name: 'rgba16f'!

Usage

You only need to download shaders you actually use. The following part of this section assumes that they are in shaders directory in the mpv configure folder (usually ~/.config/mpv/shaders on Linux).

Use glsl-shaders="prescaler.hook" option to load those shaders. (This will override other user shaders, use glsl-shaders-append in that case)

glsl-shaders="~~/shaders/ravu-lite-r3.hook"

All shaders are for one pass only. If you want to have 4x upscaling, trigger the same shader twice. All the shaders here are generated with max-downscaling-ratio set to 1.414213. They will be disabled if upscaling is not necessary.

glsl-shaders-append="~~/shaders/ravu-lite-r3.hook"
glsl-shaders-append="~~/shaders/ravu-lite-r3.hook"

For nnedi3 prescaler, neurons and window settings are indicated in the filename.

For ravu prescaler, radius setting is indicated in the filename. r3 (with radius=3 setting) shaders are generally recommended, those shaders achieve good balance between performance and quality.

About RAVU

RAVU (Rapid and Accurate Video Upscaling) is a set of prescalers inspired by RAISR (Rapid and Accurate Image Super Resolution). It comes with different variants to fit different scenarios.

ravu and ravu-lite upscale only luma plane (of a YUV video), which means chroma planes will be handled by --cscale later. ravu-lite is faster and sharper. It also introduces no half pixel offset.

ravu-yuv and ravu-rgb upscale video after all planes are merged. This happens after --cscale (or other chroma prescaler) is applied. ravu-yuv assumes YUV video and will fail on others (for example, PNG picture).

ravu-zoom is another variant which is able to upscale video to arbitrary ratio directly. Its sharpness is close to ravu-lite. But it renders at target resolution, so expect it to be much slower than ravu for perfect 2x upscaling.

ravu-zoom also comes with a chroma variant which is mostly a drop-in replacement of --cscale.

Known Issue

1. ravu-lite is incompatible with --fbo-format=rgb10_a2 (default for some OpenGL ES implementation). Use rgba16f or rgba16 if available.
2. ravu-[zoom-]r4-{rgb,yuv} causes distortion with lower-end intel card.

License

Shaders in this repo are licensed under terms of LGPLv3. Check the header of each file for details.