wasm-audio-resampler v2.0.0

Soxr Webassembly Resampler

This lib exposes the Soxr resampler to Javascript with WebAssembly. It doesn't have any dependancy and support NodeJS or a WebContext. Typescript typings are also provided. This can be used for audio application.

How to use

import SoxrResampler, {SoxrResamplerTransform, SoxrDatatype} from 'wasm-audio-resampler';

const channels = 2; // minimum is 1, no maximum
const inRate = 44100; // frequency in Hz for the input chunk
const outRate = 44000; // frequency in Hz for the target chunk
const inputDatatype = SoxrDatatype.SOXR_INT16; // input datatype, can be 0 = Float32, 1 = Float64, 2 = Int32, 3 = Int16
const outputDatatype = SoxrDatatype.SOXR_FLOAT32; // output datatype, can be 0 = Float32, 1 = Float64, 2 = Int32, 3 = Int16

// you need a new resampler for every audio stream you want to resample
// it keeps data from previous calls to improve the resampling
const resampler = new SoxrResampler(
  channels,
  audioTest.inRate,
  audioTest.outRate,
  inputDatatype,
  outputDatatype
);

await resampler.init();

const pcmData = Buffer.from(/* interleaved PCM data in signed 16bits int */);
const res = resampler.processChunk(pcmData);
// res is also a buffer with interleaved signed 16 bits PCM data
// once there is no more data to be resampled, you need to flush the resampler to get the last data in the internal buffer:
const flushedData = resampler.processChunk(null);
// you can then concat these buffers:
const resampled = Buffer.concat([res, flushedData]);

You can look at the src/test.ts for more information.

Building

You need NodeJS and Emscripten to build this module. First clone the soxr git submodule with git submodule update --init --recursive then apply the deps/soxr_emscripten.patch patch to fix a bug with invalid function signature (cd deps/soxr && git apply ../soxr_emscripten.patch). Finally use scripts/build_emscripten.sh to compile soxr and build the Wasm files.

Test music by https://www.bensound.com