[libdrm,0/3] Add support for low-color frame buffer formats

Message

Geert Uytterhoeven March 7, 2022, 8:53 p.m. UTC

Hi all,

A long outstanding issue with the DRM subsystem has been the lack of
support for low-color displays, as used typically on older desktop
systems, and on small embedded displays.

This patch series adds support for color-indexed frame buffer formats
with 2, 4, and 16 colors.  It has been tested on ARAnyM using a
work-in-progress Atari DRM driver supporting 2, 4, 16, and 256 colors.

Overview:
  - Patch 1 optimizes the C8 SMPTE color LUT, for reuse with formats
    providing less colors,
  - Patch 2 introduces the new C[124] formats,
  - Patch 3 adds SMPTE pattern support for the C4 format.

Note that so far there is no specific pattern support for the C1 and C2
formats.

Please refer to [1] for more information.

Thanks for your comments!

[1] "[PATCH v2 00/10] drm: Add support for low-color frame buffer formats"
    https://lore.kernel.org/r/[e-mail]

Geert Uytterhoeven (3):
  util: Optimize C8 SMPTE color LUT
  drm_fourcc: Add DRM_FORMAT_C[124]
  util: Add SMPTE pattern support for C4 format

 include/drm/drm_fourcc.h  |  5 ++-
 tests/modetest/buffers.c  | 15 +++++++
 tests/modetest/modetest.c | 13 ++++--
 tests/util/format.c       |  3 ++
 tests/util/pattern.c      | 93 +++++++++++++++++++++++++++++----------
 tests/util/pattern.h      |  2 +-
 6 files changed, 101 insertions(+), 30 deletions(-)