8‑bit and 10‑bit in Gumlet

When you upload a video, Gumlet can generate:

8‑bit renditions (typically Rec. 709, SDR) for maximum compatibility.
10‑bit renditions (used for HDR workflows) for higher dynamic range and better gradients on supported devices.

Both ladders can be packaged into a single HLS manifest, so compatible players and browsers can automatically pick the best stream.

Mainstream browsers and devices fall back to 8‑bit SDR when HDR is not available.
HDR‑capable pipelines can leverage 10‑bit streams for better quality.

How this relates to HDR

HDR workflows usually rely on 10‑bit depth, wider color spaces, and different transfer functions (for example, BT.2020 + PQ for HDR10).[web:38]

Gumlet’s pipeline can:

Preserve 10‑bit/HDR information in dedicated renditions, and
Provide 8‑bit/SDR renditions for environments that do not support HDR.

Your HLS playlist can therefore contain:

8‑bit SDR variants for broad compatibility.
10‑bit HDR‑ready variants for capable players.

Why can colors look washed out?

If a browser or player:

Does not fully support HDR, or
Mis‑handles 10‑bit streams and tone mapping,

The result can be:

Low contrast, greyish highlights.
Desaturated colors compared to the same video in a different browser.

In our internal tests, 8‑bit and 10‑bit variants in the same HLS stream played correctly in major browsers, but some niche Chromium‑based browsers rendered HDR variants incorrectly, producing washed‑out images, even though the encodes and metadata were valid.

Recommended usage

For widest compatibility, ensure your workflow includes 8‑bit SDR renditions.
Use 10‑bit/HDR renditions to enhance quality on supported devices, but do not rely on perfect HDR behavior in all long‑tail browsers.
When debugging color issues:
- Compare playback in Chrome, Safari, and Firefox.
- Check which variant (8‑bit vs 10‑bit) is being selected.
- If only one specific browser shows washed‑out colors, treat it as a browser limitation rather than an encoding error.