I have some variant fx like one is your PM; and another is here :
http://gigatron3k.free.fr/html5/C2/FX/glitch2
the glitch fx you want use noise textured pic , som i must use Computed texture to insert it..
This is nice, but the noise is not crucial. I swap channel1 to 0 on shadertoy and works ok. This can be very very cool if you can implement this freeze effect from herehttps://www.shadertoy.com/view/llS3Rc# for some block.
I edit(like noob) this code for snapshot delay (but i dont know how to add aplha blocks and other stuff from shader with google eye )
just paste on toy(and grab to channel0 video with Van Damme or Britney):
#define speed 20.
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
vec2 uv = fragCoord.xy / iResolution.xy;
float pixel = mod(floor(fragCoord.y),1.);
float timeId = mod(floor(iGlobalTime * speed),4.0);
if(pixel != timeId) discard;
if(timeId == 0.) {
fragColor = texture2D(iChannel0, uv );
} else {
fragColor = texture2D(iChannel0, uv );
}
}