Use local assets for blurring

src/livekit/BlurBackgroundTransformer.ts

@@ -0,0 +1,62 @@
+/*
+Copyright 2024 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only
+Please see LICENSE in the repository root for full details.
+*/
+
+import {
+  BackgroundTransformer,
+  VideoTransformer,
+  VideoTransformerInitOptions,
+} from "@livekit/track-processors";
+import { ImageSegmenter } from "@mediapipe/tasks-vision";
+
+interface WasmFileset {
+  /** The path to the Wasm loader script. */
+  wasmLoaderPath: string;
+  /** The path to the Wasm binary. */
+  wasmBinaryPath: string;
+}
+
+// n.b. this only includes the SIMD versions of the WASM files which have good support:
+// https://caniuse.com/?search=simd
+const wasmFileset: WasmFileset = {
+  wasmLoaderPath: new URL(
+    "../../node_modules/@mediapipe/tasks-vision/wasm/vision_wasm_internal.js",
+    import.meta.url,
+  ).href,
+  wasmBinaryPath: new URL(
+    "../../node_modules/@mediapipe/tasks-vision/wasm/vision_wasm_internal.wasm",
+    import.meta.url,
+  ).href,
+};
+
+const modelAssetPath = new URL(
+  "../mediapipe/imageSegmenter/selfie_segmenter.tflite",
+  import.meta.url,
+).href;
+
+export class BlurBackgroundTransformer extends BackgroundTransformer {
+  public async init({
+    outputCanvas,
+    inputElement: inputVideo,
+  }: VideoTransformerInitOptions): Promise<void> {
+    // call super.super.init()
+    await VideoTransformer.prototype.init.call(this, {
+      outputCanvas,
+      inputElement: inputVideo,
+    });
+
+    this.imageSegmenter = await ImageSegmenter.createFromOptions(wasmFileset, {
+      baseOptions: {
+        modelAssetPath,
+        delegate: "GPU",
+        ...this.options.segmenterOptions,
+      },
+      runningMode: "VIDEO",
+      outputCategoryMask: true,
+      outputConfidenceMasks: false,
+    });
+  }
+}