---
description: μ-law companded PCM audio codec definition, defining legal codec strings, decoder configs, and packet data formats.
---

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import { VPBadge } from 'vitepress/theme'
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<VPBadge type="info" text="Audio codec" />

# μ-law PCM codec registration

## Description

The μ-law companded PCM audio codec, specified in [ITU-T G.711](https://www.itu.int/rec/T-REC-G.711) Tables 2a and 2b.

## Codec ID

```ts
'ulaw'
```

## `EncodedPacket` data

The packet's data must be a sequence of bytes of arbitrary length (divisible by the channel count), where each byte is a μ-law encoded PCM sample. For multichannel audio, samples from different channels are interleaved.

## `EncodedPacket` type

The packet's type is always `'key'`.

## `AudioDecoderConfig` codec string

```ts
'ulaw'
```

## `AudioDecoderConfig` description

`description` is not used for this codec.