# General information about color space
Following is some general information about color space.
**Topics**
+ [Definitions](color-space-definitions.md)
+ [Color space standards](color-space-standards.md)
+ [Requirements for inputs](color-space-inputs-requirements.md)
+ [Requirements for outputs](color-space-output-requirements.md)
+ [Support for conversion and passthrough](color-space-conversions.md)
# Definitions
There are four aspects to color space:
+ The specific *color space* that applies to the video content. The color space specifies a range of pixel colors that can apply to the content.
+ The *color space metadata*, which identifies the color space being used. If this metadata is present, the content is said to be *marked* for a color space.
+ The *brightness function* that applies to the color space. The brightness function controls the brightness of each pixel. The brightness is also known as gamma tables, lookup tables (LUT), electro-optical transfer function (EOTF), and transfer function.
+ The *brightness metadata*, which identifies the brightness function being used.
+ The *display metadata * that applies to the color space. Not all standards have this metadata.
The source video might use a specific *color space* and a specific *brightness function*. The source video might also carry *color space metadata *that describes aspects of the color.
# Color space standards
To read this table, find a color space in the first column, then read across to identify the three sets of color data for that color space.
****
| Elemental Live term for the color space | Complies with this color space standard | Complies with this brightness function standard | Complies with this standard for display metadata |
| --- | --- | --- | --- |
| 601 or Rec\$1601 | SDR rec. 601 | BT.1886 | Not applicable. This color space doesn't include display metadata. |
| 709 or Rec\$1709 | SDR rec. 709 | BT.1886 | Not applicable. This color space doesn't include display metadata. |
| SDR 2020 | rec.2020 | BT.1886 | Not applicable. This color space doesn't include display metadata. |
| HDR10 | rec.2020 | SMPTE ST 2084 (PQ) | SMPTE ST 2086 |
| HLG or HLG 2020 | rec.2020 | HLG rec. 2020 | Not applicable. This color space doesn't include display metadata. |
| Dolby Vision 5.0. Only a Dolby Vision-compliant downstream player can handle this color space | A Dolby implementation of the ITP color representation format specified in the Rec. ITU-R BT.2100 | SMPTE ST 2084 (PQ) | Proprietary Dolby Vision metadata (RPU), on a per-frame basis |
| Dolby Vision 8.1. Both a Dolby Vision-compliant and an HDR10-compliant downstream player can handle the color space | rec.2020 | SMPTE ST 2084 (PQ) | Proprietary Dolby Vision metadata (RPU), on a per-frame basis, and SMPTE ST 2086 on a per-stream basis |
Note that HDR10 and HLG use the same color space. They use different brightness functions and display metadata standards.
# Requirements for inputs
**Supported input types**
AWS Elemental Live can work with the color space in all [supported input types](ref-inputs-and-codecs.md).
**Input requirements for producing Dolby Vision outputs**
There are specific requirements for a source that you plan to convert to Dolby Vision. These requirements are stipulated by Dolby Vision, and relate to the minimal video quality required to produce Dolby Vision outputs that meet the Dolby Vision standard::
+ The video source must be HD or 4K resolution. In other words, the source must be 1080p or better.
+ The video source must be in the HDR10 color space.
# Requirements for outputs
**Supported output types**
You can include any color space in any video in any supported output type. The main consideration in choosing to convert to a color space in an output is whether the intended downstream player can handle the color space.
**Output requirements for HDR10 or Dolby Vision**
There are specific requirements for converting to HDR10 or Dolby Vision outputs.
****
| Requirement | Applies to converting to HDR10 | Applies to converting to Dolby Vision |
| --- | --- | --- |
| Codec must be HEVC. | Yes | Yes |
| Profile must include the term Main10. | Yes | Yes |
| For HD outputs, the event must run on an L800 series appliance. | No | Yes |
| For 4K outputs, the event must run on an appliance in the L730 series, the L840 series, or the L880 series. | No | Yes |
| You must obtain a license from the [AWS Elemental Support Center Activations](https://console.aws.amazon.com/elemental-appliances-software/home?region=us-east-1#/activations). Note that pass through of Dolby Vision doesn't require a license. | No | Yes |
# Support for conversion and passthrough
## Handling of supported color spaces
Elemental Live can read the color space information of any supported color space. It can convert the color space or pass through the color space as follows:
****
| Supported color space | Pass through | Convert |
| --- | --- | --- |
| 601 | Yes | Yes, to any supported color space except Dolby Vision. |
| 709 | Yes | Yes, to any supported color space except Dolby Vision. |
| SDR 2020 | Yes | Yes, to any supported color space except Dolby Vision. |
| HDR10 | Yes | Yes, to any supported color space. If you want to convert to Dolby Vision, see [Requirements for inputs](color-space-inputs-requirements.md) and [Requirements for outputs](color-space-output-requirements.md). |
| HLG | Yes | Yes, to any supported color space except Dolby Vision. |
| Dolby Vision 5.0 | No. See the note after this table. | No. |
| Dolby Vision 8.1 | Yes | No. |
| Unsupported color space | Yes | No. |
### Ingesting Dolby Vision 5.0
Elemental Live can't ingest video in the Dolby Vision 5.0 color space. An event with this type of input will fail immediately when ingest starts.
## Handling of unsupported color spaces
We can't make any promises about handling of video that uses an unsupported color space. Any of the following might apply:
+ Elemental Live might be able to ingest the input and pass through the color space and the color space metadata.
+ Or it might ingest the input but produce unacceptable output.
+ Or it might fail to ingest the input, so that the event follows the input loss behavior routine (for example, it might display a slate in the output).
Elemental Live is never able to convert an unsupported color space to another color space.