x-labz

function keepAliveTask(task) {
  while (true) {
    try {
      log('starting task:', task.name)
      task()
    }
    catch (error) {
      log('task crashed:', task.name, error )
    }
  }

x-labz

      // gl.readPixels(0, 0, W, H, gl.RGBA, gl.UNSIGNED_BYTE, bufferRGB);

      const init = {
        timestamp: videoFrame.timestamp,
        codedWidth: W,
        codedHeight: H,
        format: "RGBA",
      };
      //const newFrame = new VideoFrame(bufferRGB, init);
      const newFrame = new VideoFrame(gl.canvas, init);

x-labz

const W = 1280; 
const H = 720; 

async function start() {
  const buffer = new Uint8Array(W * H * 1.5);
  const bufferRGB = new Uint8Array(W * H * 4);

  const transformer = new TransformStream({
    async transform(videoFrame, controller) {
      const startTs = performance.now();

x-labz

precision highp float;

uniform sampler2D u_image;
uniform sampler2D u_image_frame;
uniform vec2 u_resolution;
varying vec2 v_texCoord;

void main() {
  float x_offset = mod( gl_FragCoord.y ,2.0  ) < 1.0 ? 0.5 : 0.0 ;
  vec4 y4 =  texture2D(u_image_frame, vec2 ( v_texCoord.x / 1.0  , v_texCoord.y / 1.5  )   )  ;

x-labz

var glRef = {};

function loadImage(src) {
  return new Promise((resolve, reject) => {
    const img = new Image();
    img.onload = () => {
      resolve(img);
    };
    img.src = src;
  });

x-labz

attribute vec2 a_position;
attribute vec2 a_texCoord;
uniform vec2 u_resolution; 
varying vec2 v_texCoord;
  
void main() {  
  gl_Position =  vec4(( (a_position / u_resolution * 2.0) - 1.0)  * vec2(1, -1), 0, 1);  
  v_texCoord = a_texCoord;  
}

x-labz

const WASM_FILE = "./main.wasm";

const W = 640;
const H = 360;

let mem_in, mem_out;
let mem_bg_img;
let instance = null;
let memoryStates = new WeakMap();

x-labz

#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

#define WASM_EXPORT __attribute__((visibility("default")))

uint16_t w;   // frame width
uint16_t h ;  // frame height
uint8_t * input_buffer;
uint8_t * out_buffer;

x-labz

const W = 640;   // video frame width
const H = 360;   // video frame height
const pixelData = await imageLoader("./seaside.png");  // get the pixel data of the backgroung image in RGBA format 

const buffer = new Uint8Array(W * H * 1.5); // byte buffer for the incoming frame in YUV 422 format
const bufferRGB = new Uint8Array(W * H * 4); // byte buffer for the result frame in RGBA format

const transformer = new TransformStream({
    async transform(videoFrame, controller) {
      const copyResult = await videoFrame.copyTo(buffer);

x-labz

[
 {offset: 0, stride: 640},
 {offset: 921600, stride: 320},
 {offset: 1152000, stride: 320}
]