What Is HDR Video? HDR10, HDR10+, Dolby Vision and HLG Explained

Streaming menus now label films “HDR”, “Dolby Vision” or “HDR10+”, and phones record HDR by default. But what is HDR video, and does it actually look better? This guide explains high dynamic range in plain language, compares the formats you will see, and covers what creators and streaming platforms need to get right.

Dynamic range in one paragraph

Dynamic range is the gap between the darkest and brightest parts of a picture that can be shown with detail. Standard video (SDR) was designed around old CRT televisions, which peaked at roughly 100 nits of brightness. Real scenes have far more range: sunlight on water, a dark alley at night, a candle in a dim room. SDR compresses all of that into a narrow band, so bright highlights clip to flat white and shadows turn to murky grey. HDR carries a much wider range, and modern displays can show highlights of 600, 1,000 or even several thousand nits alongside deep, detailed blacks.

More than brightness: colour and bit depth

HDR usually brings two other upgrades.

Wider colour gamut. SDR uses the BT.709 colour space. HDR video uses BT.2020, which contains many more saturated colours, especially deep reds and greens. Current displays cannot show all of BT.2020, but most cover a large part of the DCI-P3 range inside it.

Higher bit depth. SDR is usually 8-bit, 256 shades per colour channel. HDR needs at least 10-bit, 1,024 shades, to avoid visible banding across the much larger brightness range. Some formats support 12-bit.

So HDR is really a package: more brightness range, more colour, and more precision to describe both.

Transfer functions: PQ and HLG

A video signal has to describe how bright each pixel should be. The rule for converting signal values to light is called the transfer function. HDR uses two:

PQ (Perceptual Quantizer, SMPTE ST 2084). Describes absolute brightness levels up to 10,000 nits, spread in a way that matches human perception. Used by HDR10, HDR10+ and Dolby Vision.

HLG (Hybrid Log-Gamma). Developed by the BBC and NHK for broadcasting. It is relative rather than absolute, and designed so the same signal looks acceptable on SDR screens and better on HDR screens. No metadata needed, which suits live TV.

The HDR formats

HDR10

The open baseline. Uses PQ, 10-bit, BT.2020 and static metadata: one set of values for the whole film, describing the mastering display and the brightest and average light levels. Every HDR TV and HDR-capable streaming service supports it.

Its limitation is the static metadata. A single tone-mapping choice has to work for the darkest cave scene and the brightest desert scene alike.

HDR10+

Samsung’s royalty-free extension of HDR10, with dynamic metadata that can change scene by scene or even frame by frame. The TV can adapt tone mapping to each shot. Supported by Samsung, Panasonic and several streaming services.

Dolby Vision

Dolby’s proprietary format, also with dynamic metadata, supporting up to 12-bit and very high mastering brightness. Widely supported on high-end TVs, Apple devices, many streaming sticks and major services. It requires licensing from Dolby, and content is usually graded and processed with Dolby’s tools.

HLG

The broadcast format. No metadata, backwards compatible with SDR displays to a reasonable degree. Common for live sports and TV broadcasts, and some cameras and phones record it.

What viewers need to see HDR

Every link in the chain has to support it:

1. HDR content, from a service that offers it on your plan.
2. A device and app that decode HDR: most modern streaming sticks, smart TVs, recent phones and many laptops.
3. An HDR display with enough brightness to make it worthwhile. Many cheaper “HDR” monitors reach only 300 to 400 nits and look only slightly different from SDR.
4. HDR enabled in the operating system or TV settings.
5. A capable connection: HDMI 2.0 or newer with HDCP 2.2 for 4K HDR. See HDCP explained.
6. Enough bandwidth, typically 15 to 25 Mbps for 4K HDR. Our guide to streaming bandwidth requirements has the numbers.

If any link fails, you may get SDR, or worse, HDR that looks dim and washed out because the display is interpreting it wrongly.

Why HDR sometimes looks worse

People often switch HDR on and dislike the result. Common reasons:

• The display is not bright enough, so the TV compresses highlights and the whole picture looks dim.
• Windows HDR mode on an SDR-leaning monitor makes desktop apps and SDR video look grey.
• Tone mapping in a player is poor, flattening contrast.
• Brightness settings such as eco modes or ambient light sensors reduce peak output.

Good HDR on a capable screen is striking. Weak HDR on a weak screen is often worse than SDR.

Creating and encoding HDR video

For creators, a few rules keep HDR intact from camera to viewer.

Capture in a log or HDR profile with 10-bit recording where possible. Many phones now record HDR (often Dolby Vision or HLG) automatically.

Grade on an HDR-capable monitor, or at least check your output on a real HDR TV. Grading HDR on an SDR screen is guesswork.

Encode with a 10-bit codec. H.264 in 8-bit cannot carry HDR properly. Use HEVC Main 10, VP9 Profile 2 or AV1 10-bit. Our comparison of H.264, HEVC and AV1 explains the trade-offs, and the codec support checker shows which HDR-capable codecs a device can decode.

Set the colour metadata correctly: BT.2020 primaries, PQ or HLG transfer, and for HDR10 the mastering display and light-level values. A file with HDR pixels but missing metadata will play as washed-out SDR.

In FFmpeg with x265, an HDR10 encode includes options like:

-c:v libx265 -pix_fmt yuv420p10le \
-x265-params "colorprim=bt2020:transfer=smpte2084:colormatrix=bt2020nc:hdr10=1:master-display=G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,1):max-cll=1000,400"

The mastering display values come from your grading monitor; the example shows a common P3-D65 1,000-nit master.

Provide an SDR version. Many viewers still have SDR screens. Services either encode a separate SDR ladder or rely on the device to tone map. For your own site, offering both through your bitrate ladder is the safest choice.

HDR in streaming manifests

In HLS, HDR renditions are marked with the VIDEO-RANGE attribute (PQ or HLG) and codec strings such as hvc1.2.4.L153.B0 for HEVC Main 10 or dvh1 for Dolby Vision. In DASH, supplemental properties describe the colour and transfer characteristics. Players use these signals to pick HDR only for devices that can show it. Paste your master playlist into the M3U8 analyzer to check which renditions carry HDR signalling.

Is HDR worth it?

For films, nature, sport and games watched on a good TV: yes, often dramatically. For talking-head videos, lectures and screen recordings: usually not. HDR adds encoding complexity, bigger files and more testing, for little visible benefit on that kind of content. Choose it where the content and the audience’s screens can show the difference.

HDR on phones and laptops

HDR is no longer just a TV feature. Many recent phones have bright OLED screens that show HDR video well, and they record it too. iPhones capture Dolby Vision HDR, and many Android phones record HDR10 or HLG. That creates a new problem for creators: footage that looks vivid on the phone can look strange once uploaded, edited or shared.

If you edit phone footage, check whether your editing software reads the HDR metadata correctly. Some apps display it as flat and grey, or clip the highlights. If you do not intend to deliver in HDR, convert the footage to SDR with a proper tone-mapping step early, rather than hoping the export will sort it out.

Laptops are more mixed. Some premium models have genuine HDR panels with high brightness and local dimming. Many labelled “HDR” reach only modest brightness and give a limited effect. On Windows, HDR must be switched on in display settings, and some apps also need their own HDR option enabled.

For viewers, a simple rule applies: if HDR looks worse than SDR on a device, turn it off for that device. The format only helps when the screen can show it.

HDR and streaming costs

HDR renditions usually need slightly higher bitrates than SDR at the same resolution, because 10-bit video carries more information and viewers are more sensitive to banding in smooth gradients. Offering both HDR and SDR ladders also doubles part of your encoding and storage. For a small library that matters little. For a large one, run the numbers with the video hosting cost calculator before committing.

The short version

HDR shows brighter highlights, deeper shadows and richer colour. It needs the right screen. Without one, stick with SDR.

Summary

HDR video carries a far wider range of brightness and colour than standard video, using 10-bit or higher precision, the BT.2020 colour space and either the PQ or HLG transfer function. HDR10 is the universal baseline with static metadata, HDR10+ and Dolby Vision add scene-by-scene dynamic metadata, and HLG serves live broadcasting. To get HDR right, every step, from capture and grading to encoding, metadata, device, display and connection, has to support it. When they do, the difference is obvious.