HDR preview with VDO Player

Apple displays do most of the work for us: macOS exposes real EDR headroom, the compositor hands 10-bit+ data to the panel, and local tone mapping handles any headroom mismatch between content and display automatically.

Reference Preset for macOS Apple XDR displays

For accurate HDR preview on Apple XDR panels, set the system to a reference preset:

1. Open System Settings → Displays.
2. Select the XDR display.
3. Choose a Preset appropriate for your deliverable:
   • Apple Display (P3-1600 nits) for general HDR preview.
   • HDR Video (P3-ST 2084) for HDR10 / PQ mastering reference — clamps SDR white to 100 nits, peak to 1000, surface lit at the PQ curve.
   • HLG Video (P3-ST 2100 HLG) for HLG deliverables.
4. Keep the room reasonably dim. Apple's XDR backlight modulates per frame; ambient light throws off highlight perception.

VDO Player reads the display's EDR headroom live, so switching presets while a stream is playing takes effect within a second.

Pro reference monitors via Blackmagic DeckLink (macOS Player)

For grading suites and QC rooms that use a dedicated HDR reference monitor (Sony BVM-HX310, Flanders XMP series, Canon DP-V series, etc.), VDO Player on macOS can output the decoded stream to the monitor via a Blackmagic DeckLink card instead of — or in addition to — the Mac's own display.

This path keeps HDR metadata intact end-to-end:

• 10-bit 4:2:2 YUV over SDI (DeckLink 4K / 8K / Extreme cards)
• HDR InfoFrame carrying SMPTE ST.2086 mastering display metadata and MaxCLL / MaxFALL when the source stream provides them
• PQ (ST.2084) and HLG transfer functions passed through unchanged

Setup

1. Install the latest Blackmagic Desktop Video driver from blackmagicdesign.com.
2. Connect a DeckLink SDI output to your reference monitor.
3. In Blackmagic Desktop Video Setup, set the output to match your deliverable — typically 2160p 23.98 / 24 / 25 / 29.97, YUV 4:2:2, 10-bit.
4. In VDO Player, open Settings → Output and pick DeckLink (SDI) as the preview destination.
5. Set your reference monitor to the correct HDR mode (PQ or HLG, Rec.2020 primaries, SDI input).

Apple TV player (coming soon)

A dedicated VDO Player for tvOS is in active development. The target is 4K HDR playback on:

• Apple TV 4K (2nd gen, A12) — HDR10, HLG, Dolby Vision 8.4 passthrough
• Apple TV 4K (3rd gen, A15) — HDR10, HLG, Dolby Vision 8.4 passthrough

tvOS handles HDR at the platform level similarly to macOS (AVSampleBufferDisplayLayer with ITU-R BT.2100 colour spaces), so once the player ships it will get true HDR output into any HDR10 or HLG TV connected via HDMI, with no extra configuration beyond pairing the Apple TV to your VDO account. We will update this page and publish release notes the day the tvOS build goes into public beta.

Web browsers (on supported displays)

VDO's web player renders HDR natively on any browser + display combination that exposes HDR to web content. Unlike the native player, which uses Metal and CAMetalLayer directly, the web player has two HDR paths and picks the best available at runtime:

• <video> element + MediaStreamTrackGenerator / VideoTrackGenerator — the most reliable HDR path. The browser hands PQ / HLG frames straight to the system compositor, which tone-maps to the display exactly the way Netflix or YouTube do.
  • Chrome 94+ (desktop and Android) via MediaStreamTrackGenerator.
  • Safari 18+ (macOS and iOS) via VideoTrackGenerator — worker-only, standard W3C API.
• WebGPU canvas (rgba16float + toneMapping: "extended") — wide-gamut rendering today, with true luminance headroom arriving when importExternalTexture gains HDR support (gpuweb#5236). Used for overlays and custom render surfaces.

Confirmed working combinations

Detecting whether your browser + display is actually in HDR mode

Open the browser's DevTools console on the player page and run:

window.matchMedia('(dynamic-range: high)').matches

• true — the OS is reporting an HDR display and HDR mode is on. The web player will render HDR.
• false — either the display is SDR, or HDR is off at the OS level (common on Windows — HDR must be explicitly enabled per-display). The player falls back to tone-mapped SDR.

Known limitations of the web path

• Windows HDR is fiddly. You must enable HDR in Windows Display Settings and keep the monitor on an HDR input. If Windows reports HDR as off, the browser renders SDR even on an HDR panel.
• Firefox does not yet expose HDR metadata to content. The stream plays, but tone-mapped to SDR.
• Older Chrome (<129) on macOS did not pass PQ metadata to the compositor reliably. Upgrade if HDR streams look flat in an otherwise HDR-capable browser.
• iPad / iPhone Safari in standalone PWA mode follows the same HDR rules as Safari proper.

SDR fallback

When the player detects a display with EDR headroom ≤ 1.05 (i.e. essentially no extra headroom above SDR white), it automatically falls back to an SDR render path:

• PQ streams are tone-mapped with a 203-nit SDR reference white.
• HLG streams are displayed at nominal gamma ~1.0 (the standard backward-compatible HLG behaviour).

The image will be watchable but is not reference — highlights are compressed and wide-gamut colours are clipped to Rec.709. Use only for layout, framing, or rough QC, never for colour judgements.

Verifying you are actually getting HDR

It is surprisingly easy to think you are previewing HDR when you are actually looking at a tone-mapped SDR fallback. To confirm:

1. With an HDR stream playing, open Window → Show Diagnostics in VDO Player (⌘⇧D).
2. Check the Display section:
   • EDR headroom should be > 1.05 on an XDR display, typically 4.0 – 8.0 on the Pro Display XDR at the HDR Video preset.
   • Layer colour space should be itur_2100_PQ or itur_2100_HLG.
   • Layer pixel format should be rgba16Float.
3. A pure-white (SDR 1.0) patch should look visibly less bright than specular highlights above SDR white (values > 1.0). If they look the same brightness, you are tone-mapping.
4. On the Pro Display XDR at the HDR Video preset, a 203-nit (midtone) patch should look like typical SDR white; headroom above that should be clearly super-bright.

Troubleshooting

The picture is flat and dim The stream is likely being decoded as SDR. Check that your source is actually sending HDR metadata — the Streamer Diagnostics panel will show Transfer: PQ or HLG. If it says Rec.709 or sRGB, fix the sender, not the player.

Highlights look clipped at SDR white You are on an SDR display, or the Mac is on an SDR preset. Switch the display preset to Apple Display (P3-1600 nits) or HDR Video (P3-ST 2084).

Picture is purple / over-saturated on the reference monitor The reference monitor is decoding the signal as SDR Rec.709. Switch its input mode to Rec.2020 PQ (HDR10) or Rec.2020 HLG to match the stream.

EDR headroom reads 1.0 even on an XDR display macOS only grants real EDR headroom to layers that explicitly request it. The player requests it automatically when HDR content starts, but the headroom reading can lag by one frame after a preset change. Scrub or pause/play the stream to force a refresh.

DeckLink output is black Check that Blackmagic Desktop Video Setup shows a valid output format, the cable is SDI-rated for 12G (for 4K60), and the reference monitor is set to the same resolution and frame rate. Swap cables before blaming the driver.

Apple TV HDR playback Not shipping yet. Follow the Downloads page for release announcements.

Roadmap

• tvOS player — HDR10 and HLG passthrough to Apple TV 4K and any HDR TV connected over HDMI.
• Windows reference monitor output via Blackmagic DeckLink (feature-complete on macOS, porting to Windows next).
• Dolby Vision (profile 8.4) passthrough for streams that carry it — currently displayed as HDR10 via the base-layer PQ signal.
• HDR preview on the web player — Chrome on HDR Windows and macOS already supports it at the WebCodecs layer; we are validating colour accuracy before recommending it for client review.

Have a display you would like us to add to the tested list? Get in touch via Support.