> **Experimental**
>
> `@aws-cdk/aws-medialive-alpha` is an [**experimental**](/stability) (alpha) package: its API may change in any release, without a major version bump.
# Ac3SettingsProps

Properties for AC3 codec settings.

- Stability: [Experimental](/cdk/api/stability.html)
- Source: [`lib/audio-codec-settings.ts`](https://github.com/aws/aws-cdk/blob/v2.274.0-alpha.0/packages/@aws-cdk/aws-medialive-alpha/lib/audio-codec-settings.ts#L963)

## Example

```ts
// AAC stereo
const aac = medialive.EncodeConfiguration.audio({
  name: 'aac_stereo',
  codec: medialive.AudioCodecSettings.aac({
    bitrate: Bitrate.kbps(192),
    codingMode: medialive.AacCodingMode.CODING_MODE_2_0,
  }),
});

// AC3 5.1
const ac3 = medialive.EncodeConfiguration.audio({
  name: 'ac3_surround',
  codec: medialive.AudioCodecSettings.ac3({
    bitrate: Bitrate.kbps(384),
    codingMode: medialive.Ac3CodingMode.CODING_MODE_3_2_LFE,
  }),
});
```

## Properties

- `attenuationControl`: [Ac3AttenuationControl](/cdk/api/v2/docs/@aws-cdk_aws-medialive-alpha.Ac3AttenuationControl.html) — Applies a 3 dB attenuation to the surround channels.

  **Default:** service default

  Used only for the 3/2 coding mode.

- `bitrate`: [Bitrate](/cdk/api/v2/docs/aws-cdk-lib.Bitrate.html) — The average bitrate.

  **Default:** service default

- `bitstreamMode`: [Ac3BitstreamMode](/cdk/api/v2/docs/@aws-cdk_aws-medialive-alpha.Ac3BitstreamMode.html) = Ac3BitstreamMode.COMPLETE_MAIN — Specifies the bitstream mode (bsmod) for the emitted AC-3 stream.

- `codingMode`: [Ac3CodingMode](/cdk/api/v2/docs/@aws-cdk_aws-medialive-alpha.Ac3CodingMode.html) = Ac3CodingMode.CODING_MODE_2_0 — The Dolby Digital coding mode.

- `dialNorm`: number — The dialogue normalization level (1–31).

  **Default:** service default

- `drcProfile`: [Ac3DrcProfile](/cdk/api/v2/docs/@aws-cdk_aws-medialive-alpha.Ac3DrcProfile.html) — If set to filmStandard, adds dynamic range compression signaling to the output bitstream.

  **Default:** service default

- `lfeFilter`: [Ac3LfeFilter](/cdk/api/v2/docs/@aws-cdk_aws-medialive-alpha.Ac3LfeFilter.html) = Ac3LfeFilter.DISABLED — When set to enabled, applies a 120Hz lowpass filter to the LFE channel prior to encoding.

  Valid only in codingMode32Lfe mode.

- `metadataControl`: [Ac3MetadataControl](/cdk/api/v2/docs/@aws-cdk_aws-medialive-alpha.Ac3MetadataControl.html) — When set to followInput, encoder metadata is sourced from the DD, DD+, or DolbyE decoder that supplies this audio data.

  **Default:** service default