63 lines
No EOL
2.5 KiB
TypeScript
63 lines
No EOL
2.5 KiB
TypeScript
/// <reference path="Codec.ts"/>
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abstract class BasicCodec implements Codec {
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protected _audioContext: OfflineAudioContext;
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protected _decodeResampler: AudioResampler;
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protected _encodeResampler: AudioResampler;
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protected _codecSampleRate: number;
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on_encoded_data: (Uint8Array) => void = $ => {};
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channelCount: number = 1;
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samplesPerUnit: number = 960;
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constructor(codecSampleRate: number) {
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this.channelCount = 1;
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this.samplesPerUnit = 960;
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this._audioContext = new OfflineAudioContext(1, 1024,44100 );
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this._codecSampleRate = codecSampleRate;
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this._decodeResampler = new AudioResampler();
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this._encodeResampler = new AudioResampler(codecSampleRate);
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}
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abstract name() : string;
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abstract initialise();
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abstract deinitialise();
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abstract reset() : boolean;
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protected abstract decode(data: Uint8Array) : Promise<AudioBuffer>;
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protected abstract encode(data: AudioBuffer) : Promise<Uint8Array | string>;
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encodeSamples(cache: CodecClientCache, pcm: AudioBuffer) {
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this._encodeResampler.resample(pcm).then(buffer => this.encodeSamples0(cache, buffer))
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.catch(error => console.error("Could not resample PCM data for codec. Error:" + error));
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}
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private encodeSamples0(cache: CodecClientCache, buffer: AudioBuffer) {
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cache._chunks.push(new BufferChunk(buffer)); //TODO multi channel!
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while(cache.bufferedSamples(this.samplesPerUnit) >= this.samplesPerUnit) {
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let buffer = this._audioContext.createBuffer(this.channelCount, this.samplesPerUnit, this._codecSampleRate);
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let index = 0;
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while(index < this.samplesPerUnit) {
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let buf = cache._chunks[0];
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let cpyBytes = buf.copyRangeTo(buffer, this.samplesPerUnit - index, index);
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index += cpyBytes;
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buf.index += cpyBytes;
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if(buf.index == buf.buffer.length)
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cache._chunks.pop_front();
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}
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this.encode(buffer).then(result => {
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if(result instanceof Uint8Array) this.on_encoded_data(result);
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else console.error("[Codec][" + this.name() + "] Could not encode buffer. Result: " + result);
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});
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}
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return true;
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}
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decodeSamples(cache: CodecClientCache, data: Uint8Array) : Promise<AudioBuffer> {
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return this.decode(data).then(buffer => this._decodeResampler.resample(buffer));
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}
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} |