Audio

Release: 1.4 | October 30, 2026

Component Audio Tracks

• Component audio tracks must be delivered independently of the Original Production Language Master.
• Component audio tracks must only contain one Soundfield group per file. Example: A component audio delivery consisting of 2.0 (stereo) and 5.1 (surround) must be contained within two independent files (one for 2.0 and one for 5.1).
• Each Soundfield group must be arranged into a single track. e.g. 5.1 would be a single track with 6 channels.
• Content with 5.1 surround must be provided with a separate corresponding 2.0 track.
• Audio must be delivered as Linear PCM with Sample bit Depth (24 bit) and Sample Rate (48kHz).
• Audio must conform (be synchronous) with the Primary Language Master.
• Padding at the top is not required, if padding is included it must either match the Master Composition or must not exceed 5s.
• Padding at the tail should not be included, if padding is included it must match the Master Composition.

Component audio tracks must be delivered as either Broadcast WAVE Format (MBWF / RF64) or Material Exchange Format (MXF).

Broadcast WAVE Format

• Aligned with primary video SOM (01:00:00:00)
  • Padding is not required; if padding is included, it must not exceed 5s at the Head of the program. Padding at the Tail must not be present
• Including TimeReference timecode synchronous with Original Production Language Master
• Valid channel configurations: (2.0: L, R or Lt, Rt, M1, M2) or (5.1 Surround: L, R, C, LFE, Ls, Rs,)

Material Exchange Format

• File format inside MXF must be BWF
• Including SMPTE timecode track aligned & synchronous with Original Production Language Master
• Channels labeled in the file metadata using Multichannel Audio Labeling as specified in SMPTE ST 377-4:2012
• Valid channel configurations: (2.0: L, R or Lt, Rt, M1, M2) or (5.1 Surround: L, R, C, LFE, Ls, Rs,)

Dolby Atmos

Warner Bros. Discovery currently supports three formats for Dolby Atmos delivery:

1. Immersive Audio Bitstream (IAB), delivered in an IMF package only.
2. Object-based Audio Definition Model (ADM), delivered in a non-IMF package only.
3. Channel-based Audio Definition Model (ADM), delivered in a non-IMF package only.

ADM may be delivered with SDR or HDR masters. ADM is always delivered as a separate Broadcast Wave Format (.wav) file. ADM is not supported in an IMF package; for HDR deliveries, ADM must be delivered with a non-IMF package. ADM is supported at 23.976, 25, and 29.97.

5.1 and 2.0 audio will not be accepted with HDR deliveries. 5.1 and 2.0 audio will be used from the matching SDR delivery.

ADM files do not require timecode. As with component audio, ADM files must conform (be synchronous) with the SDR master.

The spoken language and audio type (e.g. primary, DVS) of each ADM file must be described in the MMC. See Technical Metadata.

Dolby Atmos Mix Requirements

The Dolby Atmos Home mix must meet the following requirements, regardless of delivery format:

1. At minimum, Atmos must be mixed in a 7.1.4 room.
2. For near field mixes, the most common monitoring levels are 79dB or 82dB SPL.
3. Audio loudness must conform to the Warner Bros. Discovery loudness specification, otherwise Warner Bros. Discovery reserves the right to reject the content. Loudness and True Peak should be measured using the loudness analysis in the Dolby Atmos Renderer software or via a third-party tool.
4. Atmos files must be synchronous to and match the final picture length exactly as long-play and not separate reels. Leader and sync pop shall be removed.
5. Adding First Frame of Action (FFOA) in the Dolby Renderer is optional but is not required.
6. Where both exist, a near field mix is preferred over a Theatrical mix.

Descriptive Video/Audio Description

Warner Bros. Discovery requires the delivery of Descriptive Video / Audio Description Dolby Atmos tracks, where pre-existing, to be delivered in the following manner:

1. Descriptive Video/Audio Description must conform to the primary program video.
2. Descriptive Video/Audio Description must adhere to the Master Technical Specifications.

Option 1: Immersive Audio Bitstream (IAB)

IAB deliveries must be compliant with SMPTE ST 2067-201:2019 Immersive Audio Bitstream (IAB) Level 0 Plug-in and must be part of the IMF CPL. See High Dynamic Range (HDR) for IMF package requirements.

1. Beds and objects must, at the minimum, be separated by Dialog, Narration (if present), Music, and Effects.
2. All beds and objects are encoded and will always be audible.
3. IAB must contain multiple beds maintaining DME separation to the extent possible. Beds and Objects for Dialog, Music, and Effects (DME) must be created.
4. IAB Atmos is not supported for 29.97 delivery.
5. There must not be more than 128 individual audio tracks.

• Object count must not exceed 118.
• Bed count must not exceed 10.

6. Each Soundfield group must be arranged into a single track.
7. All audio channels MUST be labeled in the file metadata using Multichannel Audio Labeling as specified in SMPTE ST 377-4:2012. Specifically, Spoken Language, MCA Audio Content Kind, MCA Tag Name, MCA Tag Symbol (see IAB Audio Track Layout for values). To be IMF compliant a value MUST be entered for MCA Audio Element Kind, MCA Title, and MCA Title Version. WBD does not require specific values for these fields, “n/a” is suggested/acceptable.

IAB Audio Track Layout

1. Exclude track(s) if not available, do not fill with silent or duplicate tracks.
2. The MCA Tag Symbol must correspond with the MCA Tag Name. The Immersive Audio track must follow the Immersive Audio Labeling section (§5.10) of SMPTE ST 2067-201:2019.
3. The following are required fields for IMF files:
   • Spoken Language (RFC 5646)
   • MCA Audio Content Kind
   • MCA Tag Name
   • MCA Tag Symbol

Option 2: Object-based ADM

Object-based ADM deliveries must be a Dolby Atmos master ADM BWF file conforming to ITU-R BS.2076 (Audio Definition Model) and ITU-R BS.2088 (BW64), as exported from the Dolby Atmos Renderer. The file must include Dolby Atmos metadata.

1. Beds and objects must, at the minimum, be separated by Dialog, Narration (if present), Music, and Effects.
2. All beds and objects are encoded and will always be audible.
3. The ADM file must contain multiple beds maintaining DME separation to the extent possible. Beds and Objects for Dialog, Music, and Effects (DME) must be created.
4. The total channel count (beds and objects combined) must not exceed 128.
5. The ADM file must be delivered as a single file containing the complete program, with a single audio track and no video or timed text.
6. Files larger than 4 GB must use RF64.

Option 3: Channel-based ADM

Channel-based ADM deliveries must be an ADM BWF file conforming to ITU-R BS.2076 (Audio Definition Model) and ITU-R BS.2088 (BW64), containing a 5.1.4 channel-based Dolby Atmos mix.

1. The ADM file must contain a single 5.1.4 bed (exactly 10 channels). No other channel configurations are accepted.
2. Channels must be labeled in the ADM metadata in the order shown in the table below.
3. The ADM file must be delivered as a single file containing the complete program, with a single audio track and no video or timed text.
4. Files larger than 4 GB must use RF64.

Audio Loudness

The finished full mix tracks of any program or element must have an average overall loudness or average dialog-gated loudness level of -24 LKFS/LUFS (plus or minus 2 dB), as measured using a meter compliant with ITU-1770-3 and ITU-R BS.1770-4.

1. One of the follow requirements must be met:

• Dialog-gated target average loudness for program audio must be ∑ -24 LKFS +/- 2 dB (minus LFE if applicable).
  OR
• Overall target average loudness for program audio should be ∑ -24 LKFS +/- 2 dB (minus LFE if applicable).

2. True Peak must not exceed -2 dBTP (dynamics processing should be applied as needed).
3. The loudness range must not exceed 20 LUFS (dynamics processing should be applied as needed).

Release History

v1.4 October 30, 2026

1. Added Dolby Atmos section. Dolby Atmos requirements moved from High Dynamic Range (HDR).
2. Added object-based ADM and channel-based ADM (5.1.4) as supported Dolby Atmos formats, in addition to IAB. ADM may be delivered with SDR masters or with HDR masters in a non-IMF package.
3. Moved HDR audio requirements from High Dynamic Range (HDR): IMF Multichannel Audio Labeling, IAB Audio Track Layout, near field mix preference, Descriptive Video/Audio Description, and the 5.1 and 2.0 audio restriction for HDR deliveries.

v1.3 December 02, 2025

1. Added Audio Loudness.

v1.2 April 13, 2022

1. Changed 'WarnerMedia' to 'Warner Bros. Discovery'

v1.1 May 14, 2021

1. Added padding language (at the top/tail) to the Component Audio Tracks Section
2. Moved DVS section to under the Audio Track Layout sections of the Licensed Content (SDR) / Originals (SDR) Specifications
3. Added channel configuration to MXF