@echogarden/wave-codec
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A fully-featured WAVE format encoder and decoder. Written in pure TypeScript.
137 lines • 7.41 kB
JavaScript
import { readUint32LE, writeAscii, writeUint32LE } from './utilities/BinaryUtilities.js';
import { concatUint8Arrays } from './utilities/Utilities.js';
import { decodeAscii } from './encodings/Ascii.js';
import { WaveFormatHeader, SampleFormat } from './WaveFormatHeader.js';
import { bufferToFloat32Channels, float32ChannelsToBuffer } from './audio-utilities/AudioBufferConversion.js';
export function encodeWaveFromFloat32Channels(audioChannels, sampleRate, bitDepth = 16, sampleFormat = SampleFormat.PCM, speakerPositionMask = 0) {
const audioDataBuffer = float32ChannelsToBuffer(audioChannels, bitDepth, sampleFormat);
const resultWaveBuffer = encodeWaveFromBuffer(audioDataBuffer, sampleRate, audioChannels.length, bitDepth, sampleFormat, speakerPositionMask);
return resultWaveBuffer;
}
export function encodeWaveFromBuffer(audioBuffer, sampleRate, channelCount, bitDepth, sampleFormat, speakerPositionMask = 0) {
// Create format subchunk
const shouldUseExtensibleFormat = bitDepth > 16 || channelCount > 2;
const formatSubChunk = new WaveFormatHeader(channelCount, sampleRate, bitDepth, sampleFormat, speakerPositionMask);
const formatSubChunkBuffer = formatSubChunk.serialize(shouldUseExtensibleFormat);
// Create data subchunk
const audioBufferLength = audioBuffer.length;
const dataSubChunkBuffer = new Uint8Array(4 + 4 + audioBufferLength);
writeAscii(dataSubChunkBuffer, 'data', 0);
let dataChunkLength = audioBufferLength;
// Ensure large data chunk length is clipped to the maximum of 4294967295 bytes
if (dataChunkLength > 4294967295) {
dataChunkLength = 4294967295;
}
writeUint32LE(dataSubChunkBuffer, dataChunkLength, 4);
dataSubChunkBuffer.set(audioBuffer, 8);
// Create RIFF subchunk
const riffChunkHeaderBuffer = new Uint8Array(12);
writeAscii(riffChunkHeaderBuffer, 'RIFF', 0);
let riffChunkLength = 4 + formatSubChunkBuffer.length + dataSubChunkBuffer.length;
// Ensure large RIFF chunk length is clipped to the maximum of 4294967295 bytes
if (riffChunkLength > 4294967295) {
riffChunkLength = 4294967295;
}
writeUint32LE(riffChunkHeaderBuffer, riffChunkLength, 4);
writeAscii(riffChunkHeaderBuffer, 'WAVE', 8);
// Concatenate subchunks to produce the resulting wave buffer
const resultWaveBuffer = concatUint8Arrays([riffChunkHeaderBuffer, formatSubChunkBuffer, dataSubChunkBuffer]);
return resultWaveBuffer;
}
export function decodeWaveToFloat32Channels(waveData, ignoreTruncatedChunks = true, ignoreOverflowingDataChunks = true) {
const { decodedAudioBuffer, sampleRate, channelCount, bitDepth, sampleFormat, speakerPositionMask } = decodeWaveToBuffer(waveData, ignoreTruncatedChunks, ignoreOverflowingDataChunks);
const audioChannels = bufferToFloat32Channels(decodedAudioBuffer, channelCount, bitDepth, sampleFormat);
return {
audioChannels,
sampleRate
};
}
export function decodeWaveToBuffer(waveData, ignoreTruncatedChunks = true, ignoreOverflowingDataChunks = true) {
let readOffset = 0;
const riffId = decodeAscii(waveData.subarray(readOffset, readOffset + 4));
if (riffId !== 'RIFF') {
throw new Error('Not a valid wave file. No RIFF id found at offset 0.');
}
readOffset += 4;
let riffChunkSize = readUint32LE(waveData, readOffset);
readOffset += 4;
const waveId = decodeAscii(waveData.subarray(readOffset, readOffset + 4));
if (waveId !== 'WAVE') {
throw new Error('Not a valid wave file. No WAVE id found at offset 8.');
}
if (ignoreOverflowingDataChunks && riffChunkSize === 4294967295) {
riffChunkSize = waveData.length - 8;
}
if (riffChunkSize < waveData.length - 8) {
throw new Error(`RIFF chunk length ${riffChunkSize} is smaller than the remaining size of the buffer (${waveData.length - 8})`);
}
if (!ignoreTruncatedChunks && riffChunkSize > waveData.length - 8) {
throw new Error(`RIFF chunk length (${riffChunkSize}) is greater than the remaining size of the buffer (${waveData.length - 8})`);
}
readOffset += 4;
let formatSubChunkBodyBuffer;
const dataBuffers = [];
while (true) {
const subChunkIdentifier = decodeAscii(waveData.subarray(readOffset, readOffset + 4));
readOffset += 4;
let subChunkSize = readUint32LE(waveData, readOffset);
readOffset += 4;
if (!ignoreTruncatedChunks && subChunkSize > waveData.length - readOffset) {
throw new Error(`Encountered a '${subChunkIdentifier}' subchunk with a size of ${subChunkSize} which is greater than the remaining size of the buffer (${waveData.length - readOffset})`);
}
if (subChunkIdentifier === 'fmt ') {
formatSubChunkBodyBuffer = waveData.subarray(readOffset, readOffset + subChunkSize);
}
else if (subChunkIdentifier === 'data') {
if (!formatSubChunkBodyBuffer) {
throw new Error('A data subchunk was encountered before a format subchunk');
}
// If the data chunk is truncated or extended beyond 4 GiB,
// the data would be read up to the end of the buffer
if (ignoreOverflowingDataChunks && subChunkSize === 4294967295) {
subChunkSize = waveData.length - readOffset;
}
const subChunkData = waveData.subarray(readOffset, readOffset + subChunkSize);
dataBuffers.push(subChunkData);
}
// All sub chunks other than 'fmt ' and 'data' (e.g. 'LIST', 'fact', 'plst', 'junk' etc.) are ignored
// This addition operation may overflow if JavaScript integers were 32 bits,
// but since they are 52 bits, it is okay:
readOffset += subChunkSize;
// Break if readOffset is equal to or is greater than the size of the buffer
if (readOffset >= waveData.length) {
break;
}
}
if (!formatSubChunkBodyBuffer) {
throw new Error('No format subchunk was found in the wave file');
}
if (dataBuffers.length === 0) {
throw new Error('No data subchunks were found in the wave file');
}
const waveFormat = WaveFormatHeader.deserializeFrom(formatSubChunkBodyBuffer);
const sampleFormat = waveFormat.sampleFormat;
const channelCount = waveFormat.channelCount;
const sampleRate = waveFormat.sampleRate;
const bitDepth = waveFormat.bitDepth;
const speakerPositionMask = waveFormat.speakerPositionMask;
// Note: the returned audio buffer must be ensured to be
// memory aligned to the target bit depth, like 2 bytes or 4 bytes for 16 and 32 bits.
const decodedAudioBuffer = concatUint8Arrays(dataBuffers);
return {
decodedAudioBuffer,
sampleRate,
channelCount,
bitDepth,
sampleFormat,
speakerPositionMask
};
}
export function repairWaveData(waveData) {
const { decodedAudioBuffer, sampleRate, channelCount, bitDepth, sampleFormat, speakerPositionMask } = decodeWaveToBuffer(waveData, true, true);
const reEncodedWaveData = encodeWaveFromBuffer(decodedAudioBuffer, sampleRate, channelCount, bitDepth, sampleFormat, speakerPositionMask);
return reEncodedWaveData;
}
export * from './audio-utilities/AudioBufferConversion.js';
export { SampleFormat } from './WaveFormatHeader.js';
//# sourceMappingURL=WaveCodec.js.map