Convert pcm data from one format to another
npm install pcm-convertjs
const convert = require('pcm-convert')
//convert data from float32 to uint8 array
let uint8arr = convert([0, 0.1, 0.1, 0], 'float32', 'uint8')
//convert interleaved uint8 to planar float32 array
let float32arr = convert(new Uint8Array([127, 200, 127, 200]), 'uint8 stereo interleaved', 'float32 planar')
//deinterleave keeping the same data type
let int8arr = convert(new Int8Array([-100,100,-100,100]), 'interleaved', 'planar')
//change endianness keeping the same data type
let float32be = convert(new Float32Array([1,.5,-.5,-1]), 'le', 'be')
//use objects as formats
let float64 = convert(float32be, {
dtype: 'float32',
channels: 2,
interleaved: false,
endianness: 'be'
}, {
dtype: 'float64',
interleaved: true,
endianness: 'le'
})
//skip source format string, convert directly to data format
let uint16 = convert(new Uint8Array([0,255]), 'uint16')
//put data into target container skipping format strings
convert(new Uint8Array([0,255]), new Uint16Array(2))
//full arguments case
let uint16arr = convert([0, 0, 1, 1], 'float32 le stereo planar', 'uint16 interleaved be', new Uint16Array(4))
`
API
$3
Takes data in src container and converts from srcFormat to dstFormat. Format can be whether a string with tags or an object with properties, see audio-format module. If srcFormat is skipped, it is detected from src. Optionally a destination container can be provided as dst, and in case if dstFormat is skipped, it will be detected from dst.
#### Source
Source format is inferred from src data type and extended with srcFormat properties. By default source is considered planar mono le. Source data types:
| Type | Dtype |
|---|---|
| Array | float32 |
| Float32Array | float32 |
| Float64Array | float64 |
| ArrayBuffer | uint8 |
| Buffer | uint8 |
| Uint8Array | uint8 |
| Uint8ClampedArray | uint8 |
| Uint16Array | uint16 |
| Uint32Array | uint32 |
| Int8Array | int8 |
| Int16Array | int16 |
| Int32Array | int32 |
#### Format
Can be defined as dtype string with tags, eg. 'uint8 interleaved mono le', 'float64 planar quad' (some tags can be skipped), or an object with the following properties:
| Property | Meaning |
|---|---|
| dtype | Data type string: uint8, uint16, uint32, int8, int16, int32, float32, float64, array (only dstFormat), arraybuffer (only dstFormat). |
| interleaved | Boolean indicating if data has interleaved or planar layout. |
| channels | Number of channels in source: mono, stereo, quad, 5.1. |
| endianness | be or le`, defaults to OS endianness. |