What is HDR?
High dynamic range media represents a wider span of brightness than standard dynamic range media. HDR systems commonly combine increased bit depth with defined transfer functions, color primaries, and metadata.
How HDR works
HDR video encodes scene or display brightness through a defined transfer function rather than simply storing brighter RGB values. A complete signal also depends on color primaries, matrix coefficients, range, bit depth, and sometimes static or dynamic metadata. Common systems differ in whether display adaptation is guided by metadata and whether backward compatibility is built into the signal. HDR enters the workflow at grading and must survive encoding, muxing, manifests, decoding, and display mapping.
Key facts
- 1PQ and HLG are different HDR transfer systems: PQ maps code values to absolute display luminance, while HLG uses a relative approach intended to integrate with broadcast workflows.
- 2Static metadata can describe mastering and content-light characteristics for an entire program, whereas dynamic metadata may provide changing guidance by scene or frame when the format supports it.
- 3An HDR codec bitstream with missing or contradictory container signaling can be decoded using the wrong transfer or color interpretation, producing washed-out, dark, clipped, or shifted output.
When HDR matters
Developers must preserve HDR signal characteristics through encoding, packaging, and playback. Missing or mismatched metadata can cause clipped highlights, incorrect colors, or poor SDR conversion.
Common use cases for video
These examples cover video broadly, not specifically HDR.
- Preparing uploaded video for web, mobile, connected-TV, social, or editorial playback.
- Creating clips, thumbnails, captions, alternate aspect ratios, and adaptive renditions.
- Normalizing camera, screen-recording, and user-generated files into predictable outputs.
Working with video
This guidance covers video broadly, not just HDR.
A demuxer separates tracks from the container, decoders turn compressed streams into frames or samples, and filters apply spatial or temporal changes. Encoders compress the transformed tracks before a muxer writes the chosen output container.
Video compatibility is the product of codec, container, profile, level, frame rate, color, audio, and subtitles. Validate the complete output on target devices because a playable file on one decoder may fail or look different on another.
What you gain
- Standardized derivatives make diverse source files playable on target devices.
- A retained master can feed many resolutions, aspect ratios, codecs, and channels.
- Automated inspection and transformation make large upload volumes consistent.
What it costs
- More efficient codecs can lower bitrate at similar quality but usually cost more compute and may have narrower support.
- Higher resolutions and frame rates preserve more detail and motion while increasing processing and delivery requirements.
- Fast encoding settings improve throughput but can produce larger files or lower quality than slower analysis.
Before production
- 1Inspect codec, container, dimensions, frame rate, color, audio, and subtitle tracks.
- 2Test visual quality and playback support across the slowest and oldest target devices.
- 3Preserve a suitable master before applying lossy, destructive, or delivery-specific changes.