Command Line

Instructions for running Video2X from the command line.

This page does not cover all the options available. For help with more options available, run Video2X with the --help argument.

Basics

Use the following command to upscale a video by 4x with RealESRGAN:

bash

video2x -i input.mp4 -o output.mp4 -p realesrgan -s 4 --realesrgan-model realesr-animevideov3

Use the following command to upscale a video to with libplacebo + Anime4Kv4 Mode A+A:

bash

video2x -i input.mp4 -o output.mp4 -w 3840 -h 2160 -p libplacebo --libplacebo-shader anime4k-v4-a+a

Advanced

It is possible to specify custom MPV-compatible GLSL shader files with the --libplacebo-shader argument:

bash

video2x -i input.mp4 -o output.mp4 -p libplacebo -w 3840 -h 2160 --libplacebo-shader path/to/custom/shader.glsl

List the available GPUs with --list-gpus, -l:

bash

$ video2x --list-gpus
0. NVIDIA RTX A6000
        Type: Discrete GPU
        Vulkan API Version: 1.3.289
        Driver Version: 565.228.64

Select which GPU to use with the --gpu, -g argument:

bash

video2x -i input.mp4 -o output.mp4 -p realesrgan -s 4 --realesrgan-model realesr-animevideov3 -g 1

Specify arbitrary extra FFmpeg encoder options with the --extra-encoder-options, -e argument:

bash

video2x -i input.mkv -o output.mkv -p realesrgan --realesrgan-model realesrgan-plus -s 4 -c libx264rgb -e crf=17 -e preset=veryslow -e tune=film

Encoder Options

Video2X uses FFmpeg's C libraries to encode videos. Encoder options are specified in two ways:

Common options shared by all encoders are stored in a AVCodecContext struct. Below are some options set through AVCodecContext:
- Codec
- Pixel format
- Bitrate
- Keyframe interval
- Minimum and maximum quantizer
- GOP size
Encoder-specific options are stored in AVOption structs and set with the av_opt_set function. Below are some encoder-specific options for libx264:
- CRF
- Preset
- Tune
- Profile

Common options can only be set through Video2X's command line arguments. You can run video2x --help and see the Encoder options section to see the supported options.

You can specify encoder-specific options in Video2X using the --extra-encoder-option (-e) argument. To view the available options for a particular codec, run:

bash

ffmpeg -h encoder=$ENCODER

For example, to view the available options for libx264, run:

console

$ ffmpeg -h encoder=libx264
Encoder libx264 [libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10]:
    General capabilities: dr1 delay threads
    Threading capabilities: other
    Supported pixel formats: yuv420p yuvj420p yuv422p yuvj422p yuv444p yuvj444p nv12 nv16 nv21 yuv420p10le yuv422p10le yuv444p10le nv20le gray gray10le
libx264 AVOptions:
  -preset            <string>     E..V....... Set the encoding preset (cf. x264 --fullhelp) (default "medium")
  -tune              <string>     E..V....... Tune the encoding params (cf. x264 --fullhelp)
  -profile           <string>     E..V....... Set profile restrictions (cf. x264 --fullhelp)
  -fastfirstpass     <boolean>    E..V....... Use fast settings when encoding first pass (default true)
  -level             <string>     E..V....... Specify level (as defined by Annex A)
  -passlogfile       <string>     E..V....... Filename for 2 pass stats
  -wpredp            <string>     E..V....... Weighted prediction for P-frames
  -a53cc             <boolean>    E..V....... Use A53 Closed Captions (if available) (default true)
  -x264opts          <string>     E..V....... x264 options
  -crf               <float>      E..V....... Select the quality for constant quality mode (from -1 to FLT_MAX) (default -1)
  -crf_max           <float>      E..V....... In CRF mode, prevents VBV from lowering quality beyond this point. (from -1 to FLT_MAX) (default -1)
  -qp                <int>        E..V....... Constant quantization parameter rate control method (from -1 to INT_MAX) (default -1)
...

You can then set the encoder-specific options with the -e argument. The -e argument can be used multiple times to set multiple options. For example, the following arguments set the CRF to 17, the preset to veryslow, and the tune to film for libx264:

console

-e crf=17 -e preset=veryslow -e tune=film