Initial Commit

packages/media/audio/audio-engine-browser/src/adapter/fx-host.ts

@@ -0,0 +1,96 @@
+import type {
+    AudioFxPlugin,
+    ChainContext,
+} from "@suaveplan/audio-fx-plugin-base";
+import type { AudioWorkletManager } from "../worklet/worklet-manager.js";
+
+export const FX_BLOCK_SIZE = 128;
+
+interface AudioNodeLike {
+    connect: (
+        target: unknown,
+        outputIndex?: number,
+        inputIndex?: number
+    ) => unknown;
+    disconnect: (target?: unknown) => void;
+}
+
+interface FxContextLike {
+    readonly audioWorklet?: unknown;
+    readonly sampleRate: number;
+    createScriptProcessor(
+        bufferSize: number,
+        numberOfInputChannels: number,
+        numberOfOutputChannels: number
+    ): AudioNodeLike & {
+        onaudioprocess: ((e: ScriptProcessingEvent) => void) | null;
+    };
+}
+
+interface ScriptProcessingEvent {
+    readonly inputBuffer: {
+        getChannelData(channel: number): Float32Array;
+    };
+    readonly outputBuffer: {
+        getChannelData(channel: number): Float32Array;
+    };
+    readonly playbackTime: number;
+}
+
+export type FxRenderPath = "audio-node" | "worklet" | "block-processor";
+
+export interface FxHostResult {
+    readonly node: AudioNodeLike;
+    readonly path: FxRenderPath;
+}
+
+/**
+ * Select and instantiate the best available render path for a plugin:
+ *
+ * 1. `capabilities.hasAudioNode` and `plugin.createAudioNode` → native
+ *    `AudioNode` chain.
+ * 2. `capabilities.hasWorklet`, `plugin.getWorkletProcessor`, and
+ *    `context.audioWorklet` → `AudioWorkletNode`.
+ * 3. Fallback → `ScriptProcessorNode` wrapping `plugin.process()`.
+ */
+export async function createFxNode(
+    plugin: AudioFxPlugin,
+    context: FxContextLike,
+    worklets: AudioWorkletManager,
+    chainCtx: ChainContext
+): Promise<FxHostResult> {
+    if (plugin.capabilities.hasAudioNode && plugin.createAudioNode) {
+        const node = plugin.createAudioNode(context, chainCtx) as AudioNodeLike;
+        return { node, path: "audio-node" };
+    }
+    if (
+        plugin.capabilities.hasWorklet &&
+        plugin.getWorkletProcessor &&
+        context.audioWorklet
+    ) {
+        const moduleUrl = plugin.getWorkletProcessor();
+        await worklets.addModule(moduleUrl);
+        const node = worklets.createNode(
+            plugin.metadata.id
+        ) as unknown as AudioNodeLike;
+        return { node, path: "worklet" };
+    }
+    const sp = context.createScriptProcessor(FX_BLOCK_SIZE, 2, 2);
+    sp.onaudioprocess = (e: ScriptProcessingEvent): void => {
+        const input = [
+            e.inputBuffer.getChannelData(0),
+            e.inputBuffer.getChannelData(1),
+        ];
+        const output = [
+            e.outputBuffer.getChannelData(0),
+            e.outputBuffer.getChannelData(1),
+        ];
+        plugin.process(input, output, {
+            sampleRate: context.sampleRate,
+            channels: 2,
+            blockOffsetSamples: 0,
+            opts: { transportTimeSec: e.playbackTime },
+        });
+    };
+    return { node: sp, path: "block-processor" };
+}