@yume-chan/scrcpy-decoder-webcodecs/esm/video/render/webgl.js

Raw H.264 stream decoder and renderer using WebCodecs API (requires modern browser).

import { createCanvas } from "@yume-chan/scrcpy-decoder-tinyh264";
import { CanvasVideoFrameRenderer } from "./canvas.js";
const Resolved = Promise.resolve();
function createContext(canvas, enableCapture) {
    const attributes = {
        // Low-power GPU should be enough for video rendering.
        powerPreference: "low-power",
        alpha: false,
        // Disallow software rendering.
        // Other rendering methods are faster than software-based WebGL.
        failIfMajorPerformanceCaveat: true,
        preserveDrawingBuffer: !!enableCapture,
    };
    return (canvas.getContext("webgl2", attributes) ||
        canvas.getContext("webgl", attributes));
}
export class WebGLVideoFrameRenderer extends CanvasVideoFrameRenderer {
    static vertexShaderSource = `
        attribute vec2 xy;

        varying highp vec2 uv;

        void main(void) {
            gl_Position = vec4(xy, 0.0, 1.0);
            // Map vertex coordinates (-1 to +1) to UV coordinates (0 to 1).
            // UV coordinates are Y-flipped relative to vertex coordinates.
            uv = vec2((1.0 + xy.x) / 2.0, (1.0 - xy.y) / 2.0);
        }
`;
    static fragmentShaderSource = `
        varying highp vec2 uv;

        uniform sampler2D texture;

        void main(void) {
            gl_FragColor = texture2D(texture, uv);
        }
`;
    static get isSupported() {
        const canvas = createCanvas();
        return !!createContext(canvas);
    }
    #context;
    /**
     * Create a new WebGL frame renderer.
     * @param canvas The canvas to render frames to.
     * @param enableCapture
     * Whether to allow capturing the canvas content using APIs like `readPixels` and `toDataURL`.
     * Enable this option may reduce performance.
     */
    constructor(canvas, enableCapture) {
        super(canvas);
        const gl = createContext(this.canvas, enableCapture);
        if (!gl) {
            throw new Error("WebGL not supported");
        }
        this.#context = gl;
        const vertexShader = gl.createShader(gl.VERTEX_SHADER);
        gl.shaderSource(vertexShader, WebGLVideoFrameRenderer.vertexShaderSource);
        gl.compileShader(vertexShader);
        if (!gl.getShaderParameter(vertexShader, gl.COMPILE_STATUS)) {
            throw new Error(gl.getShaderInfoLog(vertexShader));
        }
        const fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
        gl.shaderSource(fragmentShader, WebGLVideoFrameRenderer.fragmentShaderSource);
        gl.compileShader(fragmentShader);
        if (!gl.getShaderParameter(fragmentShader, gl.COMPILE_STATUS)) {
            throw new Error(gl.getShaderInfoLog(fragmentShader));
        }
        const shaderProgram = gl.createProgram();
        gl.attachShader(shaderProgram, vertexShader);
        gl.attachShader(shaderProgram, fragmentShader);
        gl.linkProgram(shaderProgram);
        if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
            throw new Error(gl.getProgramInfoLog(shaderProgram));
        }
        gl.useProgram(shaderProgram);
        // Vertex coordinates, clockwise from bottom-left.
        const vertexBuffer = gl.createBuffer();
        gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);
        gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1.0, -1.0, -1.0, +1.0, +1.0, +1.0, +1.0, -1.0]), gl.STATIC_DRAW);
        const xyLocation = gl.getAttribLocation(shaderProgram, "xy");
        gl.vertexAttribPointer(xyLocation, 2, gl.FLOAT, false, 0, 0);
        gl.enableVertexAttribArray(xyLocation);
        // Create one texture to upload frames to.
        const texture = gl.createTexture();
        gl.bindTexture(gl.TEXTURE_2D, texture);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
    }
    draw(frame) {
        const gl = this.#context;
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, frame);
        gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight);
        gl.drawArrays(gl.TRIANGLE_FAN, 0, 4);
        return Resolved;
    }
}
//# sourceMappingURL=webgl.js.map