TSM.ID
108 lines
3.1 KiB
TypeScript
108 lines
3.1 KiB
TypeScript
/**
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* XCU PulsarCodec — TypeScript Port
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* Delta-based pixel compression codec ported from Rust (xcu-wasm-sdk/pulsar.rs)
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*
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* Protocol: 7 bytes per changed pixel [X_hi, X_lo, Y_hi, Y_lo, R, G, B]
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*
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* This is the PRIMARY video codec for XCU. H.264 WebCodecs is the fallback.
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* PulsarCodec sends ONLY pixels that changed since the last frame,
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* achieving near-zero bandwidth when the scene is static.
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*/
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const NEUROMORPHIC_THRESHOLD = 25;
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export class XCUPulsarCodec {
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private lastFrame: Uint8Array;
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private canvasBuffer: Uint8Array;
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private width: number;
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private height: number;
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constructor(width: number, height: number) {
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this.width = width;
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this.height = height;
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this.lastFrame = new Uint8Array(width * height * 4);
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this.canvasBuffer = new Uint8Array(width * height * 4);
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// Initialize canvas buffer to black with full alpha
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for (let i = 3; i < this.canvasBuffer.length; i += 4) {
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this.canvasBuffer[i] = 255;
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}
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}
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/**
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* Encode delta: Compare current RGBA frame to last frame.
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* Output only changed pixels as 7-byte chunks [X_hi, X_lo, Y_hi, Y_lo, R, G, B]
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*/
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encodeDelta(currentFrame: Uint8Array): Uint8Array {
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const deltaChunks: number[] = [];
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for (let i = 0; i < currentFrame.length; i += 4) {
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const currR = currentFrame[i];
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const currG = currentFrame[i + 1];
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const currB = currentFrame[i + 2];
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const lastR = this.lastFrame[i];
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const lastG = this.lastFrame[i + 1];
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const lastB = this.lastFrame[i + 2];
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const diffTotal = Math.abs(currR - lastR) + Math.abs(currG - lastG) + Math.abs(currB - lastB);
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if (diffTotal > NEUROMORPHIC_THRESHOLD) {
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const pixelIndex = (i / 4) | 0;
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const x = pixelIndex % this.width;
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const y = (pixelIndex / this.width) | 0;
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// 7-byte format: [X_hi, X_lo, Y_hi, Y_lo, R, G, B]
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deltaChunks.push(
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(x >> 8) & 0xFF, x & 0xFF,
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(y >> 8) & 0xFF, y & 0xFF,
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currR, currG, currB,
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);
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// Update last frame (only changed pixels)
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this.lastFrame[i] = currR;
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this.lastFrame[i + 1] = currG;
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this.lastFrame[i + 2] = currB;
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}
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}
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return new Uint8Array(deltaChunks);
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}
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/**
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* Decode truecolor: Render RGB asli dari delta payload ke canvas buffer.
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* Berbeda dengan decode_xray di Rust yang render hijau neon.
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*/
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decodeTruecolor(payload: Uint8Array): Uint8Array {
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for (let i = 0; i + 6 < payload.length; i += 7) {
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const x = (payload[i] << 8) | payload[i + 1];
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const y = (payload[i + 2] << 8) | payload[i + 3];
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const r = payload[i + 4];
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const g = payload[i + 5];
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const b = payload[i + 6];
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const bufIdx = (y * this.width + x) * 4;
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if (bufIdx >= 0 && bufIdx + 3 < this.canvasBuffer.length) {
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this.canvasBuffer[bufIdx] = r;
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this.canvasBuffer[bufIdx + 1] = g;
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this.canvasBuffer[bufIdx + 2] = b;
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this.canvasBuffer[bufIdx + 3] = 255; // Full alpha
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}
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}
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return this.canvasBuffer;
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}
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/**
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* Reset codec state (e.g., when switching video source)
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*/
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reset(): void {
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this.lastFrame.fill(0);
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this.canvasBuffer.fill(0);
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for (let i = 3; i < this.canvasBuffer.length; i += 4) {
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this.canvasBuffer[i] = 255;
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}
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}
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get bufferWidth(): number { return this.width; }
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get bufferHeight(): number { return this.height; }
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}
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