The four formats
| Format | Metadata | Main use | Notes |
|---|---|---|---|
| HDR10 | Static: one setting for the whole programme | Films, streaming, 4K Blu-ray | The baseline most HDR TVs support |
| HDR10+ | Dynamic: scene by scene or frame by frame | Streaming | Royalty-free; backwards compatible with HDR10 |
| HLG (hybrid log-gamma) | None needed for compatibility | Live broadcast | Developed by the BBC and NHK; standardised in ITU-R BT.2100; plays as a normal picture on SDR screens |
| Dolby Vision | Dynamic | Streaming, films | Dolby’s format, with 12-bit colour depth and dynamic metadata |
What “metadata” means here
An HDR stream carries instructions about how bright and colourful it is meant to look, so a TV that can’t reach those levels can map the picture to what it can show:
- Static metadata (HDR10) sets one mapping for the whole film or programme. The HDR10+ organisation describes it as a single tone-mapping curve, which can crush shadows or clip highlights in scenes that differ a lot from the average.
- Dynamic metadata (HDR10+ and Dolby Vision) updates the instructions as scenes change.
- HLG works differently: the signal itself is built so that SDR and HDR screens both show a sensible picture. That suits live TV, where a broadcaster can’t make separate versions on the fly.
What you need to watch HDR
All of these have to support the same format:
- The stream. Most live IPTV channels are SDR. HDR mostly appears on 4K channels and films.
- The device. For example, Amazon lists HDR10, HDR10+, HLG and Dolby Vision on its 4K Fire TV sticks, but not Dolby Vision on every model. Check your device’s specifications.
- The TV. Many 4K TVs support HDR10 and HLG; HDR10+ and Dolby Vision depend on the brand. A TV that lacks a format shows the stream in a format it does support, or in SDR.
- The connection between them. Use the TV’s HDMI input marked for 4K or HDR, and a cable rated for 4K.
HDR streams on IPTV are usually encoded with H.265 (HEVC), so the device also needs an HEVC decoder. See HEVC for IPTV.
When HDR looks wrong
- Washed-out colours: SDR content being shown as HDR, or the other way round. On streaming devices, set the output to match the content’s dynamic range (Fire TV and Apple TV have a setting for this) rather than always HDR.
- Too dark: HDR on a TV with low peak brightness, or a dim picture mode. Try the TV’s HDR picture modes, and turn off energy-saving modes that cap brightness.
- No HDR badge: the stream isn’t HDR, or a device in the chain doesn’t support its format.