This article covers encoding Dolby audio or video into distribution formats for live streaming services or file-based VOD delivery. Encoding concepts are explained in detail including encoding, transcoding or cross converting between Dolby and non-Dolby formats, sample encoding workflows and tools are given to help users to build their own on-premise solution or use professional products provided by solutions vendors and cloud services.

1. Live Encoding Workflows

Live encoding is the process of converting a live audio or video feed into a compressed digital stream for distribution. This is achieved using on-premise or cloud-based audio and video encoders that process the audio and video in real-time, compressing it for efficient transmission over the internet or broadcast infrastructure.

1. 1. Dolby Atmos Live Encoding Workflow (without Contribution):

This section outlines how a live Dolby Atmos source feed is encoded and prepared for direct delivery to IP streaming or Cable/Satellite transmission without contribution encoding. If contribution is needed, check out the next section.

In this case, the Dolby Atmos audio will have already been encoded. These live audio encoders take the live audio feed in various formats with the pre-encoded audio, such as SDI with DD+JOC, or TS with DD+JOC and then encode it for final delivery as shown in below diagram:

You can realize this workflow by using a Dolby Atmos capable live encoder. Check out the following articles from our partners to get specific information for each encoder solution:

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1. 2. Dolby Atmos Live Encoding Workflow with Contribution:

This section outlines how a live Dolby Atmos program travels from a live production environment such as stadium or studio to your home. In this example, the audio is transported from an event site, such as a stadium or production studio, to a central facility where the final changes to the audio program, such as inserting TV commercials or mixing with other program feeds, are made and the finalized audio program is distributed to the outside world.

This live event encoding and transmission workflow starts with audio program acquisition and ends with delivery to the transmission systems. It consists of audio encoding, contribution encoding, program insertion and transmission steps as outlined in below diagram:

Check out below the article for more details. This article includes a tutorial video explaining the principles of encoding and transmitting live Dolby Atmos audio, as well as it covers the following concepts which are crucial to understand live audio workflows.

Audio Contribution: There are different approaches for delivering audio program to Network Operations and Master Control room, either by encoding into contribution formats (Dolby ED2) or by using discrete audio (PCM) without encoding.

Upmixing Audio: Audio upmixing helps to maintain the immersive experience during program insertions and commercials.

Dual Production: Creating multiple programs simultaneously, the Dolby Immersive program and traditional Stereo/5.1 in a single production workflow.

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1. 3. Dolby Vision Live Encoding Workflow:

This section outlines how a live video feed is encoded into Dolby Vision for direct delivery to IP streaming or Cable/Satellite transmission. 

The standard live encoding process uses the native HDR signal coming from HDR playout or production systems. However, some encoders also support converting SDR feed into HDR before encoding into into Dolby Vision. In each case the .....Both use-cases are explained in below workflows and articles given at the end of the section.

1. 1. 1. Encoding from Live HDR Source:

Dolby Vision encoder takes HDR live signal, generates the dynamic metadata on-the-fly and then compresses the video together with metadata into Dolby Vision bitstream as shown in below workflow:

1. 1. 243. Encoding from Live SDR Source (Upmapping):

When HDR production is not available, you can upconvert standard SDR source into HDR and feed it into Dolby Vision encoder. Once the SDR signal is upconverted to HDR, dynamic metadata is generated fed into the video encoder. In technical terms, generating Dolby Vision output from SDR sources is called upmapping. Many Dolby Vision encoders support SDR conversion embedded into the core encoder pipeline, therefore the Dolby Vision encoder works seamlessly with both SDR and HDR sources. Check out the workflow diagram and the articles from our partners below.

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2. File Based (VOD) Encoding Workflows

File Based encoding is the process of converting file-based audio or video sources into a compressed digital stream for VOD delivery. This is achieved using on-premise or cloud-based audio and video encoders that process the audio and video files as explained below.

1. 1. Dolby Atmos VOD Encoding:

File-based Dolby Atmos encoders support various source formats such as DAMF, ADM BWF, MXF IAB or WAV files. The standard audio encoding workflow is shown in below diagram:

You can realize this workflow by using a Dolby Atmos supported VOD encoder which are available from Dolby or our partners. Check out below articles to get specific information for each encoder solution:

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1. 2. Dolby Vision VOD Encoding:

1. 1. 1. Encoding Dolby Vision Mezzanine:

Native Dolby Vision source mezzanine files include dynamic metadata and are delivered in a file format such as MXF, ProRes MOV or IMF/MXF packages together with the metadata. In a file based encoding workflow, a Dolby Vision mezzanine is encoded into a distribution format (i.e. HEVC or AV1 codecs) with different Dolby Vision profiles. Encoding a Dolby Vision mezzanine into HDR10 and SDR formats can also be supported, which means a single Dolby Vision source mezzanine is sufficient for all output formats. Please see sample workflow diagram below.

1. 1. 243. Encoding Dolby Vision from SDR/HDR Sources:

When Dolby Vision source is not available, you can convert a standard HDR or SDR video into Dolby Vision. This is achieved by converting the source into HDR (when the source is SDR) and then generating Dolby Vision metadata using metadata generator tool developed by Dolby. In other words, you must first convert the source video format into Dolby Vision mezzanine and then follow the standard encoding process explained in previous section.

1. 1. 6327. Transcoding Dolby Vision:

Conversion between different Dolby Vision profiles or transcoding pre-encoded video bitstreams is also possible. Some transcoding workflows are shown in below diagram and example solutions are given in resources & articles section below.

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