Package Name

Visual engine of Choi Gunhyuk

Installation

Install the package from PyPI:

pip install chgnhyk

• Details: chgnhyk installation doc

ffmpeg

• required to generate video with moviepy
• not required when using render_pyav() function in ClipRenderer

csound libcsnd6-6.0v5

• required to generate audio

Installation options

pip install "chgnhyk[window]"

• installs moderngl_window

pip install "chgnhyk[audio]"

• requires csound

pip install "chgnhyk[mediapipe]"

• installs mediapipe
• downgrades numpy to 1.26.4

pip install "chgnhyk[opencv]"

• install with opencv

pip install "chgnhyk[audio, window, mediapipe]"

• install with three options

Usage

Basic example 1:

• moviepy(ffmpeg needed) as video encoding backend

from chgnhyk import FBO, ClipRenderer
from moderngl import create_context

CTX = create_context(require=(330), standalone=True)
SIZE = (1080, 1080)

shader = '''
#version 330
out vec4 outputColor;
in vec2 UV;

uniform sampler2D bckbuffer;
uniform vec2 resolution;

uniform float timer;
uniform float loop_timer;
uniform float duration;

void main() {
    vec2 uv = UV;
    vec2 rs = resolution;

    outputColor = vec4(uv, loop_timer, 1.);
}
'''

scene = FBO(
    ctx = CTX, size = (1080, 1080), shader = shader
)

clip = ClipRenderer(duration=2, fps=30, rest_time=0.)
clip.addFBOPass("", scene)

clip.render_frame_sample(clip.duration * 0.0)
clip.extractImage((f"test_{clip.t}.jpg"))

vid = clip.render()
vid.write_videofile(str("test.mp4"), fps=clip.fps)

clip.release()
CTX.release()

Basic example 2:

• pyav as video encoding backend

from chgnhyk import FBO, ClipRenderer
from moderngl import create_context

CTX = create_context(require=(330), standalone=True)
SIZE = (1080, 1080)

shader = '''
#version 330
out vec4 outputColor;
in vec2 UV;

uniform sampler2D bckbuffer;
uniform vec2 resolution;

uniform float timer;
uniform float loop_timer;
uniform float duration;

void main() {
    vec2 uv = UV;
    vec2 rs = resolution;

    outputColor = vec4(uv, loop_timer, 1.);
}
'''

scene = FBO(
    ctx = CTX, size = (1080, 1080), shader = shader
)

clip = ClipRenderer(duration=2, fps=30, rest_time=0.)
clip.addFBOPass("", scene)

clip.render_frame_sample(clip.duration * 0.0)
clip.extractImage((f"test_{clip.t}.jpg"))
clip.render_pyav("test.mp4")

clip.release()
CTX.release()

Video example:

• create "sample" folder
• create "shaders" folder and put shader files there

shader file in "shaders" folder

#version 330
out vec4 outputColor;
in vec2 UV;

uniform sampler2D bckbuffer;
uniform vec2 resolution;
uniform sampler2D VID;
uniform vec2 VID_res;

uniform float timer;
uniform float loop_timer;
uniform float duration;

#define PI 3.14159265

float rand(vec3 p){
    float sd1 = dot(p, vec3(31.3131,23.2323,17.1717));
    float sd2 = dot(p, vec3(13.1313,15.1515,19.1919));
    float sv = sin(sd1) + sin(sd2);
    return fract(sv * 45678.654321);
}

vec2 rotate(vec2 p, float a){
    return vec2(
        p.x * cos(a) - p.y * sin(a),
        p.x * sin(a) + p.y * cos(a)
    );
}

float sd_segment(vec2 p, vec2 a, vec2 b, float w){
    vec2 ba = b - a;
    vec2 pa = p - a;
    vec2 dr = normalize(ba);
    float l = length(ba);

    float dt = dot(pa, dr);
    vec2 h = a + dt * dr;

    float dst = length(h-p)-w;
    if(dt <= .0){
        dst = length(p-a)-w;
    }

    if(dt >= l){
        dst = length(p-b)-w;
    }

    return dst;
}

void main() {
    vec2 uv = UV;
    vec2 rs = resolution;
    uv = (uv-.5);
    uv *= rs/rs.y;

    vec2 sc = vec2(40.);
    
    vec2 iuv = floor(uv*sc);
    if(mod(iuv.y,2.) == .0){
        uv.x -= .5/sc.x;
    }
    iuv = floor(uv*sc);
    vec2 fuv = fract(uv*sc)-.5;
    vec2 vtc = (iuv/sc)*rs.y/rs + .5;
    vec4 vsamp = texture(VID, vtc);
    vec4 ovsamp = texture(VID, UV);

    float h = length(vsamp.rgb)/length(vec3(1.));
    h = floor(h * 8.)/8.;
    fuv = rotate(fuv, h * PI * 2.);
    float sh = sd_segment(fuv, vec2(-.4,.0), vec2(.4,.0), .02);
    sh = 1.-smoothstep(.0,.001 * sc.x,sh);

    vec3 col;
    col = mix(vsamp.rgb, vec3(.1,1.,.1), sh);
    outputColor = vec4(col, 1.);
}

main python script

from chgnhyk import FBO, load_shader, ClipRenderer
from moderngl import create_context
from pathlib import Path

work_path = Path(__file__).parent
shader_path = work_path.joinpath("shaders/")
sample_path = work_path.joinpath("sample/")


CTX = create_context(require=(330), standalone=True)
ratio = 1
SIZE = (1080, 1080) # change to match video file

scene = FBO(ctx=CTX, size=SIZE, shader=load_shader(shader_path.joinpath("scene.glsl")))

clip = ClipRenderer(duration=5, fps=30, rest_time=0.) #8 #30
scene.set_uniform("duration", clip.duration)
clip.addFBOPass(name = 'scene', render_pass = scene)
clip.addVideo(sample_path.joinpath("video.mp4"), "VID", 8)

clip.render_frame_sample(clip.duration * 0.0)
clip.extractImage(sample_path.joinpath(f"test_{clip.t}.jpg"))

vid = clip.render()
vid.write_videofile(str(sample_path.joinpath("test.mp4")), fps=clip.fps)

clip.release()
CTX.release()

Requirements

• Python 3.9 or later

License

This project is licensed under the MIT License.

Author

Choi Gunhyuk

Links

• Pypi: https://pypi.org/project/chgnhyk
• GitHub: https://github.com/chgnhyk