FFMPEG 通过OPENGL 给视频添加震荡波特效

FFMPEG 通过OPENGL 给视频添加震荡波特效

这个代码也是通过在 shadertoy 上版本稍微修改了版本.

uniform sampler2D texture;
uniform float u_time;
uniform vec2 u_resolution;

void main()
{
    vec2 uv = gl_FragCoord.xy/u_resolution.xy;
    vec2 pos = u_resolution.xy/2.;
    
    float duration = 1.9;
    float time = mod(u_time, duration);
    float radius = 2000.* time*time;
    float thickness_ratio = .5;
    
    float time_ratio = time/duration;
   	float shockwave = smoothstep(radius, radius-2.0, length(pos - gl_FragCoord.xy));
    shockwave *= smoothstep((radius-2.)*thickness_ratio, radius-2.0,length(pos - gl_FragCoord.xy));
    shockwave *= 1.-time_ratio;
    
    vec2 disp_dir = normalize(gl_FragCoord.xy-pos);
    
    
    uv += 0.02*disp_dir*shockwave;
    vec3 col = texture2D(texture, uv).rgb;
    
    gl_FragColor = vec4(col,1.0);
}