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Implement opusdecoder with wasm-opus-decoder #129

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Merged
badaix merged 1 commit into from
May 5, 2025
Merged

Implement opusdecoder with wasm-opus-decoder #129

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3 changes: 2 additions & 1 deletion package.json
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Original file line number Diff line number Diff line change
Expand Up @@ -16,15 +16,16 @@
"@mui/icons-material": "^6.4.6",
"@mui/material": "^6.4.6",
"libflacjs": "^5.4.0",
"opus-decoder": "^0.7.7",
"react": "^19.0.0",
"react-dom": "^19.0.0",
"standardized-audio-context": "^25.3.77"
},
"devDependencies": {
"@eslint/js": "^9.21.0",
"@types/node": "^22.13.8",
"@types/react": "^19.0.10",
"@types/react-dom": "^19.0.4",
"@types/node": "^22.13.8",
"@vite-pwa/assets-generator": "^0.2.6",
"@vitejs/plugin-react-swc": "^3.8.0",
"eslint": "^9.21.0",
Expand Down
117 changes: 85 additions & 32 deletions src/snapstream.ts
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
import Flac from 'libflacjs/dist/libflac.js'
import { getPersistentValue } from './config.ts'
import { AudioContext, IAudioBuffer, IAudioContext, IAudioBufferSourceNode, IGainNode } from 'standardized-audio-context'
import { OpusDecoder as WasmOpusDecoder } from "opus-decoder";


declare global {
Expand Down Expand Up @@ -619,33 +620,7 @@ class Decoder {
return new SampleFormat();
}

decode(_chunk: PcmChunkMessage): PcmChunkMessage | null {
return null;
}
}


class OpusDecoder extends Decoder {
setHeader(buffer: ArrayBuffer): SampleFormat | null {
const view = new DataView(buffer);
const ID_OPUS = 0x4F505553;
if (buffer.byteLength < 12) {
console.error("Opus header too small: " + buffer.byteLength);
return null;
} else if (view.getUint32(0, true) !== ID_OPUS) {
console.error("Opus header too small: " + buffer.byteLength);
return null;
}

const format = new SampleFormat();
format.rate = view.getUint32(4, true);
format.bits = view.getUint16(8, true);
format.channels = view.getUint16(10, true);
console.log("Opus samplerate: " + format.toString());
return format;
}

decode(_chunk: PcmChunkMessage): PcmChunkMessage | null {
decode(_chunk: PcmChunkMessage): PcmChunkMessage | null | Promise<PcmChunkMessage | null> {
return null;
}
}
Expand Down Expand Up @@ -765,6 +740,81 @@ class FlacDecoder extends Decoder {
cacheInfo: { isCachedChunk: boolean, cachedBlocks: number } = { isCachedChunk: false, cachedBlocks: 0 };
}

class OpusDecoder extends Decoder {

constructor() {
super();
this.sampleFormat = new SampleFormat();
this.decoder = null;
}

async initDecoder() {
if (!this.decoder) {
this.decoder = new WasmOpusDecoder();
await this.decoder.ready;
await this.decoder.reset();
}
}

setHeader(buffer: ArrayBuffer): SampleFormat | null {
const view = new DataView(buffer);
const ID_OPUS = 0x4F505553;
if (buffer.byteLength < 12) {
console.error("Opus header too small:", buffer.byteLength);
return null;
} else if (view.getUint32(0, true) !== ID_OPUS) {
console.error("Invalid Opus header magic");
return null;
}

this.sampleFormat.rate = view.getUint32(4, true);
this.sampleFormat.bits = view.getUint16(8, true);
this.sampleFormat.channels = view.getUint16(10, true);

this.initDecoder()
.catch(err => console.error("Failed to initialize Opus decoder:", err));

console.log("Opus sampleformat:", this.sampleFormat.toString());
return this.sampleFormat;
}

async decode(chunk: PcmChunkMessage): Promise<PcmChunkMessage | null> {
if (!this.decoder) {
console.error("Opus decoder not initialized");
return null;
}

try {
const decoded = await this.decoder.decodeFrame(new Uint8Array(chunk.payload));

const bytesPerSample = this.sampleFormat.sampleSize();
const buffer = new ArrayBuffer(decoded.channelData[0].length * bytesPerSample * this.sampleFormat.channels);
const view = new DataView(buffer);

for (let i = 0; i < decoded.channelData[0].length; i++) {
for (let channel = 0; channel < this.sampleFormat.channels; channel++) {
const sample = Math.max(-1, Math.min(1, decoded.channelData[channel][i])) * ((1 << (this.sampleFormat.bits - 1)) - 1);
if (bytesPerSample === 4) {
view.setInt32((i * this.sampleFormat.channels + channel) * 4, sample, true);
} else {
view.setInt16((i * this.sampleFormat.channels + channel) * 2, sample, true);
}
}
}

chunk.clearPayload();
chunk.addPayload(buffer);
return chunk;
} catch (err) {
console.error("Failed to decode Opus frame:", err);
return null;
}
}

private decoder: WasmOpusDecoder | null;
private sampleFormat: SampleFormat;
}

class PlayBuffer {
constructor(buffer: IAudioBuffer, playTime: number, source: IAudioBufferSourceNode<IAudioContext>, destination: IGainNode<IAudioContext>) {
this.buffer = buffer;
Expand Down Expand Up @@ -887,7 +937,6 @@ class SnapStream {
this.decoder = new PcmDecoder();
} else if (codec.codec === "opus") {
this.decoder = new OpusDecoder();
alert("Codec not supported: " + codec.codec);
} else {
alert("Codec not supported: " + codec.codec);
}
Expand Down Expand Up @@ -925,10 +974,14 @@ class SnapStream {
} else if (type === 2) {
const pcmChunk = new PcmChunkMessage(msg.data, this.sampleFormat as SampleFormat);
if (this.decoder) {
const decoded = this.decoder.decode(pcmChunk);
if (decoded) {
this.stream!.addChunk(decoded);
}
const decodedPromise = this.decoder.decode(pcmChunk);
Promise.resolve(decodedPromise).then(decoded => {
if (decoded) {
this.stream!.addChunk(decoded);
}
}).catch(err => {
console.error("Error decoding chunk:", err);
});
}
} else if (type === 3) {
this.serverSettings = new ServerSettingsMessage(msg.data);
Expand Down