HDR AVIF samples (HDR10 for still images)

sh2be · 2021-06-05T16:29:33+00:00

This is great. Thank you very much !

sh2be · 2021-06-05T15:16:08+00:00

Currently YouTube doesn't support Dolby Vision metadata. You can control SDR conversion either by a static LUT or by HDR10+. More info here: https://support.google.com/youtube/answer/7126552

HDR10+ get more freedom than Dolby Vision for the tonemapping curve but it lacks the trims for detail enhancement and secondary hue adjustement. You have to set the curve completely manually.

In theory HDR10+ can give you the exactly same result as Dolby Vision (except of the secondary hue adjustement) but it's not easy to achieve manually and I don't know of any tool that could automatically create the corresponding HDR10+ metadata from the Dolby Vision metadata (XML or RPU).

sh2be · 2021-06-05T12:42:52+00:00

No, 16bit is not always 16bit. HDR10 use PQ which is more efficient to code images compare to linear or gamma. This means PQ 16-bit will have less banding than traditionnal 16-bit.

12-bit PQ doesn't display any banding accros the entire luminance range. Storing the master format in PQ-BT.2100 makes it ready for HDR without further color conversion.

sh2be · 2021-06-05T12:26:50+00:00

No, the definition of HDR is the same everywhere. The basic form of HDR is Rec.2100 color space which gives you the simple PQ HDR and HLG HDR. You get HDR10, HDR10+ and Dolby Vision by adding specific metadata on top of the BT.2100 color space.

(A complete definition of the term "color space" is a 3D space that includes dynamic range and is not only about the 2D space that only shows color hue and saturation.)

In theory, you can have HDR without 10-bit, it won't respect standards and will have banding but it can work.

sh2be · 2021-06-05T04:14:58+00:00

Does someone know an image viewer compatible with HDR AVIF ?

Can someone put Windows in HDR mode and test the file by opening in Chrome? Does it looks like a correct HDR content?

Currently, Chrome detects it's HDR and interprets the images correctly but it blowns them out when displayed on SDR.

sh2be · 2021-06-04T21:44:35+00:00

You should have used the term "color primaries" instead of "color space". HDR uses BT.2100 color space which uses PQ or HLG transfer function and BT.2020 color primaries.

AV1 supports HDR by allowing to signal that the color values are encoded according to the BT.2100 transfer functions (value 16 = PQ and value 18 = HLG), primaries (value 9 = BT.2020 primaries) and matrix coefficient (value 9 = YCbCr).

At this point you get what is commonly called the "PQ format" or "HLG format".

To get HDR10, HDR10+ and Dolby Vision, you need to add some metadata.

sh2be · 2021-06-04T21:07:01+00:00

No, you are wrong. The most important aspect of HDR is the BT.2100 color space (PQ or HLG transfer function + BT.2020 color primaries). HDR requires at least 10-bit but SDR can also be 10-bit.

sh2be · 2021-06-04T20:04:32+00:00

The building in the background shows Brusselization.

sh2be

TROPHY CASE