pcm-convert

Convert PCM audio data between formats.

Usage

import convert from 'pcm-convert'

// float32 → int16
convert(new Float32Array([1, -1, 0.5]), 'int16')

// interleaved uint8 → planar float32
convert(new Uint8Array([127, 200, 127, 200]), 'uint8 stereo interleaved', 'float32 planar')

// endianness swap
convert(new Float32Array([1, .5, -.5, -1]), 'le', 'be')

// planar channel arrays → interleaved PCM (replaces pcm-encode)
let left = new Float32Array([1, 0, -1])
let right = new Float32Array([0, 0.5, -0.5])
convert([left, right], 'int16 interleaved le')

// AudioBuffer → int16
convert(audioBuffer, 'int16 interleaved')

// auto-detect source, convert to target
convert(new Uint8Array([0, 255]), 'uint16')

// write into existing container
convert(new Uint8Array([0, 255]), new Uint16Array(2))

// object formats
convert(data, { dtype: 'float32', channels: 2, interleaved: false }, { dtype: 'int16', interleaved: true })

parse, detect, stringify, sampleRate

import { parse, stringify, detect, sampleRate } from 'pcm-convert'

parse('float32 stereo planar 44100')
// → { dtype: 'float32', channels: 2, interleaved: false, sampleRate: 44100 }

stringify({ dtype: 'float32', channels: 2, interleaved: false })
// → 'float32 stereo planar'

detect(new Float32Array(4))
// → { dtype: 'float32' }

detect([new Float32Array(4), new Float32Array(4)])
// → { dtype: 'float32', channels: 2, interleaved: false }

sampleRate
// → [8000, 11025, 16000, 22050, 44100, 48000, ..., 384000]

API

convert(src, srcFormat?, dstFormat?, dst?)

Convert src from srcFormat to dstFormat. If srcFormat is omitted, it is detected from src. If dst container is provided, result is written into it.

Source types

| Type | Dtype | |---|---| | Float32Array | float32 | | Float64Array | float64 | | Int8/16/32Array | int8/16/32 | | Uint8/16/32Array | uint8/16/32 | | Array | float range (-1..1) | | Float32Array[] | planar channels | | AudioBuffer | float32 planar | | ArrayBuffer | uint8 | | Buffer | uint8 |

Format

String: space-separated tokens in any order (commas, semicolons, underscores also accepted). Object: same fields as properties. Aliases in parentheses are object-only.

| Field | Values | |---|---| | dtype (type) | float32, float64, float, int8, int16, int32, int, uint8, uint16, uint32, uint | | channels (numberOfChannels) | mono, stereo, quad, 2.1, 5.1, N-channel, or number | | interleaved | interleaved, interleave, planar (or boolean) | | endianness | le, be, littleendian, bigendian | | sampleRate (rate) | 8000, 11025, 16000, 22050, 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000 (or number) | | container | array, arraybuffer, buffer |

Absorbs

v3 consolidates these packages:

• audio-format → parse, detect, stringify
• sample-rate → sampleRate
• pcm-encode (from web-audio-api) → convert([...channels], format)

License

MIT