Dolby Vision Profile 20

Profile 20 is the new Dolby Vision profile which supports delivery of Stereoscopic Video (3D Video) using MV-HEVC for an immersive video viewing experience. Stereoscopic Video (3D Video) is a technique for creating depth perception by presenting a pair of two-dimensional images to the viewer. The left 2D image is presented to the left eye and the right 2D image is presented to the right eye simultaneously. When viewed, the human brain perceives the images as a single 3D view, giving the viewer the perception of 3D depth. This technique is based on simulating the binocular disparity, the difference in image location of an object seen by the left and right eyes, naturally resulting from the eyes’ horizontal separation.

You can learn more about Dolby Vision Profile 20 here: Dolby Professional Support Community

Using the latest version of Hybrik (v1.253 or later), you can transcode Dolby Vision Profile 20 for 3D stereoscopic content.

Sources

Source task must be asset_complex type with one asset_version and two asset_components, one for each video. Each asset_component must include the multi_view parameter, one set to left and one set to right.

3D Source Task

{
    "uid": "source",
    "kind": "source",
    "payload": {
        "kind": "asset_complex",
        "payload": {
            "asset_versions": [
                {
                    "version_uid": "asset",
                    "asset_components": [
                        {
                            "component_uid": "source_filename",
                            "kind": "name",
                            "name": "{{left_source_filename}}",
                            "location": {
                                "storage_provider": "s3",
                                "path": "{{source_url}}"
                            },
                            "contents": [
                                {
                                    "kind": "video",
                                    "multi_view": "left"
                                }
                            ]
                        },
                        {
                            "component_uid": "source_filename",
                            "kind": "name",
                            "name": "{{right_source_filename}}",
                            "location": {
                                "storage_provider": "s3",
                                "path": "{{source_url}}"
                            },
                            "contents": [
                                {
                                    "kind": "video",
                                    "multi_view": "right"
                                }
                            ]
                        }
                    ]
                }
            ]
        }
    }
}

When creating a profile 20 output from a non-Dolby Vision HDR source, Hybrik creates Dolby Vision metadata during the transcode process so you don’t need to start with a Dolby Vision source. However, if your source is Dolby Vision it might have sidecar metadata (rather than embedded metadata). To add the sidecar metadata file you need to add another asset_component with the content with type metadata.

3D Source Task with Sidecar Metadata

{
    "uid": "source",
    "kind": "source",
    "payload": {
        "kind": "asset_complex",
        "payload": {
            "asset_versions": [
                {
                    "version_uid": "asset",
                    "asset_components": [
                        {
                            "component_uid": "source_filename",
                            "kind": "name",
                            "name": "{{left_source_filename}}",
                            "location": {
                                "storage_provider": "s3",
                                "path": "{{source_url}}"
                            },
                            "contents": [
                                {
                                    "kind": "video",
                                    "multi_view": "left"
                                }
                            ]
                        },
                        {
                            "component_uid": "source_filename",
                            "kind": "name",
                            "name": "{{right_source_filename}}",
                            "location": {
                                "storage_provider": "s3",
                                "path": "{{source_url}}"
                            },
                            "contents": [
                                {
                                    "kind": "video",
                                    "multi_view": "right"
                                }
                            ]
                        },
                        {
                            "component_uid": "metadata_filename",
                            "kind": "name",
                            "name": "{{metadata_filename}}",
                            "location": {
                                "storage_provider": "s3",
                                "path": "{{source_url}}"
                            },
                            "contents": [
                                {
                                    "kind": "metadata",
                                    "payload": {
                                        "standard": "dolbyvision_metadata"
                                    }
                                }
                            ]
                        }
                    ]
                }
            ]
        }
    }
}

Requirements

When preparing your source content for transcoding Dolby Vision Profile 20, keep in mind the following requirements:

Both video sources must have the same duration & frame rate
Both video sources must be aligned with the presentation timestamps (PTS)
Video source format must be HDR (PQ)
Video source format should be Apple ProRes 4444
If no Dolby Vision metadata is supplied, you must specify mastering_display_max_brightness in the source contents array to match the source brightness. Ideally your content is graded to 48 nits, 108 nits, or 300-1000 nits.

{
    "component_uid": "source_filename",
    "kind": "name",
    "name": "{{left_source_filename}}",
    "location": {
        "storage_provider": "s3",
        "path": "{{source_url}}"
    },
    "contents": [
        {
            "kind": "video",
            "multi_view": "left",
            "mastering_display_max_brightness": 1000
        }
    ]
},            

Targets

The Dolby Vision Profile 20 target settings are similar to the standard Dolby Vision transcode task but with a few more required settings.

Requirements

In addition to setting profile to "20", the following parameters must also be set:

The codec must be h265
The codec_provider must be dolby_impact
The container kind must be mp4
The maximum picture resolution of the output is 4K (4096 × 2160)

"targets": [
    {
        "file_pattern": "3D_P20_output.mp4",
        "existing_files": "replace",
        "container": {
            "kind": "mp4"
        },
        "video": {
            "codec": "h265",
            "codec_provider": "dolby_impact",
            "width": "3840",
            "bitrate_kb": "18000",
            "max_bitrate_kb": "25000",
            "vbv_buffer_size_kb": "25000",
            "bitrate_mode": "vbr",
            "dolby_vision": {
                "profile": "20"
            }
        }
    }
]

Additional Supported Features

Transcoding Dolby Vision Profile 20 also works with the following features of Hybrik:

Stitching is NOT supported for Profile 20 at this time.