Wayland Protocols 1.47 Released With Updated Color Management Protocol
Following the Color Management protocol introduced in Wayland Protocols 1.41, out today is Wayland Protocols 1.47 with various revisions to that color management and HDR support.
The Wayland color management protocol has now loosened restrictions on maxCLL and maxFALL since it isn't mandated by the ANSI/CTA-861-H specification and some movies having a maxCLL rather than the Mastering Display Luminance. Thus the prior behavior was determined to be too strict and is now loosened.
Another shortcoming of color-management-v1 is that the description identity is a 32-bit number when it should have been a 64-bit number. As a 32-bit image description identity number if allocated 100 times per second it could theoretically wrap around in 1.4 years... For anyone running a Wayland compositor and keeping an uptime of more than 1.4 years, the ready2 event now mandates a 64-bit image description ID number.
There is also a "absolute_no_adaptation" rendering intent added with a focus on color proofing applications. Setting absolute_no_adaptation indicates that it should not be adapted to the display white point so no chromatic adaptation between the surface and display is done.
The color management protocol was also updated to forbid advertising deprecated features / intents / transfer functions / names. The hope is this will ease the retirement of any deprecated functionality.
Lastly the wp_image_description_reference_v1 is added as a prerequisite for adding color management to the ext-image-copy-capture-v1 protocol.
No other changes with Wayland Protocols 1.47 besides the color management updates. The brief v1.47 announcement can be found on the Wayland mailing list.
The Wayland color management protocol has now loosened restrictions on maxCLL and maxFALL since it isn't mandated by the ANSI/CTA-861-H specification and some movies having a maxCLL rather than the Mastering Display Luminance. Thus the prior behavior was determined to be too strict and is now loosened.
Another shortcoming of color-management-v1 is that the description identity is a 32-bit number when it should have been a 64-bit number. As a 32-bit image description identity number if allocated 100 times per second it could theoretically wrap around in 1.4 years... For anyone running a Wayland compositor and keeping an uptime of more than 1.4 years, the ready2 event now mandates a 64-bit image description ID number.
There is also a "absolute_no_adaptation" rendering intent added with a focus on color proofing applications. Setting absolute_no_adaptation indicates that it should not be adapted to the display white point so no chromatic adaptation between the surface and display is done.
The color management protocol was also updated to forbid advertising deprecated features / intents / transfer functions / names. The hope is this will ease the retirement of any deprecated functionality.
Lastly the wp_image_description_reference_v1 is added as a prerequisite for adding color management to the ext-image-copy-capture-v1 protocol.
No other changes with Wayland Protocols 1.47 besides the color management updates. The brief v1.47 announcement can be found on the Wayland mailing list.