Using Dolby Atmos Encoding with AWS Elemental Server

AWS Elemental Server can encode Dolby Digital Plus with Atmos channel-based, immersive audio, Audio Descriptive Model Broadcast WAV files, or Dolby Atmos Master File.

Note

Understanding Dolby Atmos is required prerequisite knowledge for using this feature. Your input audio channels must already be set up according the Dolby Atmos standard you are using as input. For more information about Dolby Atmos, see the Dolby online documentation.

Input File Requirements for Dolby Atmos Encoding

Feature Restrictions for Dolby Atmos Encoding

Note the following restrictions in the AWS Elemental Server implementation of Dolby Atmos encoding:

• Channel-based immersive: AWS Elemental Server supports channel-based immersive (CBI) content.

• Dolby Atmos Master File (DAMF): AWS Elemental Server supports Dolby Atmos master file (DAMF). This is a collection of 3 files with the extensions, .atmos, .atmos.metadata, and .atmos.audio

• Audio Descriptive Model Broadcast WAV Format (ADM BWF): AWS Elemental Server supports ADM BWF. It is a single broadcast WAV file contains header data with the .atmos and .atmos.metadata information.

• Output codec: You can create Dolby Atmos audio outputs encoded with only the Dolby Digital Plus (EAC3) codec.

• Output containers: For file outputs, you can create Dolby Atmos audio in only in one of the video containers that supports Dolby Digital Plus: MPEG-4, MPEG-2 Transport Stream, or QuickTime.

• Output packages: For adaptive bitrate (ABR) outputs, you can create Dolby Atmos audio in any of the AWS Elemental Server output group types: CMAF, Apple HLS, DASH ISO, or Microsoft Smooth Streaming.

Setting Up a Job for Dolby Atmos Encoding

To encode 9.1.6 audio Dolby Atmos objects, provide 16 input channels of PCM audio, either in individual .wav files or as tracks in a single container.

If you provide input audio as individual .wav files, you specify them in order in your input. You specify them as Audio selector 1, Audio selector 2, and so on, up to Audio selector 16. If you provide your audio as a single file containing 16 tracks, you specify the file in your input as Audio selector 1, and then you specify the tracks individually within that audio selector.

Important

Regardless of whether they are in separate files or a single file, you must set up the channels in the following order: L, R, C, LFE, Ls, Rs, Lrs, Rrs, Lw, Rw, Ltf, Rtf, Ltm, Rtm, Ltr, Rtr.

Summary Instructions for Individual .wav File Input

If your audio input is individual .wav files, do the following:

1. Create 16 separate input audio selectors, in this order: L, R, C, LFE, Ls, Rs, Lrs, Rrs, Lw, Rw, Ltf, Rtf, Ltm, Rtm, Ltr, Rtr.

2. Create a single audio selector group; include each of the 16 audio selectors.

3. Create one output stream with a single audio tab.

   1. For Audio Codec, choose Dolby Digital Plus JOC (Atmos).

   2. For Audio Source, choose the audio selector group that you created.

Summary Instructions for Single, Multi-Track File Input

1. Create an input audio selector.

2. For Selector Type, choose Track.

3. For Track, specify your 16 channels with a comma-separated list of channel numbers. Specify them in this order: L, R, C, LFE, Ls, Rs, Lrs, Rrs, Lw, Rw, Ltf, Rtf, Ltm, Rtm, Ltr, Rtr.

4. Create one output stream with a single audio tab.

   1. For Audio Codec, choose Dolby Digital Plus JOC (Atmos).

   2. For Audio Source, keep the default Audio Selector 1.

For more detailed instructions, see one of the following procedures:

Procedure with separate audio input files

Procedure with a single audio input file

To set up a Dolby Atmos job, with audio inputs as 16 individual .wav files

1. Set up your input audio selectors as follows:

   1. On the Create New Job page, in the Input section, under Advanced, find Audio Selector 1.

   2. Choose the External file check box.

   3. For External File, provide the path and file name to the .wav file for your first channel. For Audio Selector 1, this channel must be L.

      Important

      You must set up the channels in the following order: L, R, C, LFE, Ls, Rs, Lrs, Rrs, Lw, Rw, Ltf, Rtf, Ltm, Rtm, Ltr, Rtr.

      That is, if your input audio is in separate .wav files, Audio Selector 1 must point to the L channel, Audio Selector 2 must point to the R channel, and so on.

   4. At the top of the Audio Selector sections, choose Add Audio Selector to create Audio Selector 2.

   5. Under Audio Selector 2, choose External file.

   6. Specify the path and file name to the .wav file for your second channel. For Audio Selector 2, this channel must be R.

   7. Repeat the steps to create an audio selector for the rest of your 16 channels. Choose the following channels for each selector:

      • Audio Selector 3: C

      • Audio Selector 4: LFE

      • Audio Selector 5: Ls

      • Audio Selector 6: Rs

      • Audio Selector 7: Lrs

      • Audio Selector 8: Rrs

      • Audio Selector 9: Lw

      • Audio Selector 10: Rw

      • Audio Selector 11: Ltf

      • Audio Selector 12: Rtf

      • Audio Selector 13: Ltm

      • Audio Selector 14: Rtm

      • Audio Selector 15: Ltr

      • Audio Selector 16: Rtr

2. Create an input Audio Selector Group as follows:

   1. At the top of the Audio Selector sections, choose Add Audio Selector Group.

   2. For Selector Group Name, enter a descriptive name, such as Dolby Atmos Audio Group.

   3. All the audio selectors appear below Selector Group Name. Choose each audio selector that you created earlier in this procedure.

3. In the bottom section of the Create New Job page, set up your output groups and outputs. Choose supported containers as listed in Feature Restrictions for Dolby Atmos Encoding.

4. Set up the Audio 1 tab of Stream 1.

   Note

   Avoid setting up multiple audio tabs within the stream. One audio tab represents the entire Atmos audio content.

   1. For Audio Codec, choose Dolby Digital Plus JOC (Atmos).

      For Audio Source, choose the audio selector group that you created earlier in this procedure, such as Dolby Atmos Audio Group.

   2. For the audio encoding settings, choose values that are suitable for your workflow. For more information, see the Dolby documentation for the Dolby Digital Plus Atmos encoding library.

      Note

      AWS Elemental Server automatically performs audio normalization on Dolby Digital Plus Atmos outputs. Therefore, there is no Dialnorm setting under audio encoding settings.

To set up a Dolby Atmos job, with audio input as a single file with 16 tracks

1. Set up your input audio selector as follows:

2. 1. On the Create New Job page, in the Input section, under Advanced, find Audio Selector 1.

   2. Choose the External file check box.

   3. For External Audio File, provide the path and file name to the .wav file.

   4. For Selector Type, choose Track.

   5. For Track, list your 16 PCM mono tracks in a comma-separated list. Specify them in the following order: L, R, C, LFE, Ls, Rs, Lrs, Rrs, Lw, Rw, Ltf, Rtf, Ltm, Rtm, Ltr, Rtr.

      • If the tracks of your input audio file are already in that order, then list them that way: 1, 2, 3, … 16.

      • If the tracks of your input audio file are in a different order, list them according to the specified order. For example, if your L channel is in track 3, then list 3 first.

3. In the bottom section of the Create New Job page, set up your output groups and outputs.

4. Set up the Audio 1 tab of Stream 1.

   Note

   Don't set up multiple audio tabs within the stream. One audio tab represents the entire Atmos audio content.

   1. For Audio Codec, choose Dolby Digital Plus JOC (Atmos).

      For Audio Source, keep the default Audio selector 1.

   2. For the audio encoding settings, choose values that are suitable for your workflow. For more information, see the Dolby documentation for the Dolby Digital Plus Atmos encoding library.

      Note

      AWS Elemental Server automatically performs audio normalization on Dolby Digital Plus Atmos outputs. Therefore, there is no Dialnorm setting under audio encoding settings.