wehub-resource-sync
57 lines
1.4 KiB
JavaScript
57 lines
1.4 KiB
JavaScript
class PCMRecorderProcessor extends AudioWorkletProcessor {
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constructor() {
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super();
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this.chunkSize = 4096;
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this.buffer = new Int16Array(this.chunkSize);
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this.offset = 0;
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this.pendingFrames = 0;
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this.maxPendingFrames = 10;
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}
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flushBuffer() {
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if (this.offset === 0) {
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return;
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}
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const chunk = new Int16Array(this.offset);
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chunk.set(this.buffer.subarray(0, this.offset));
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this.port.postMessage(chunk, [chunk.buffer]);
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this.offset = 0;
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this.pendingFrames = 0;
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}
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process(inputs) {
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const input = inputs[0];
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if (!input || input.length === 0) {
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return true;
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}
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const channel = input[0];
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if (!channel || channel.length === 0) {
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return true;
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}
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for (let i = 0; i < channel.length; i++) {
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let sample = channel[i];
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sample = Math.max(-1, Math.min(1, sample));
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this.buffer[this.offset++] = sample < 0 ? sample * 0x8000 : sample * 0x7fff;
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if (this.offset === this.chunkSize) {
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this.flushBuffer();
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}
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}
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if (this.offset > 0) {
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this.pendingFrames += 1;
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if (this.pendingFrames >= this.maxPendingFrames) {
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this.flushBuffer();
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}
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}
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return true;
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}
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}
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registerProcessor('pcm-recorder', PCMRecorderProcessor);
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