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| author | Geert Uytterhoeven <geert@linux-m68k.org> | 2022-07-08 20:20:54 +0200 |
|---|---|---|
| committer | Sam Ravnborg <sam@ravnborg.org> | 2022-07-09 15:35:55 +0200 |
| commit | d093100b425df6fe400881f2e62c3f0be7bf18cf (patch) | |
| tree | 9ac33e740728326e1a2dafeeed63bbcdd4f89e2c /include/uapi/drm/drm_fourcc.h | |
| parent | drm/fourcc: Clarify the meaning of single-channel "red" (diff) | |
| download | linux-d093100b425df6fe400881f2e62c3f0be7bf18cf.tar.xz linux-d093100b425df6fe400881f2e62c3f0be7bf18cf.zip | |
drm/fourcc: Add DRM_FORMAT_R[124]
Introduce fourcc codes for single-channel frame buffer formats with two,
four, and sixteen brightness levels, where there is a direct
relationship between channel value and brightness.
As the number of bits per pixel is less than eight, these rely on proper
block handling for the calculation of bits per pixel and pitch.
The fill order (the order in which multiple pixels are packed in a byte)
is the same order as used for grayscale (2, 4, and 16 levels) images in
the PNG specification, Version 1.2.
This order is also the recommended and default order (FillOrder = 1) for
bilevel and grayscale (16 levels) images in the TIFF 6.0 Specification,
and is also used for monochrome images in the PBM file format,
monochrome Linux frame buffer logos, and BDF and PSF (Linux kernel) font
files.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/96561a88e53c59cac72e66642bf4c097aacefd18.1657294931.git.geert@linux-m68k.org
Diffstat (limited to 'include/uapi/drm/drm_fourcc.h')
| -rw-r--r-- | include/uapi/drm/drm_fourcc.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h index 9521057701c4..6190fe3c6cc8 100644 --- a/include/uapi/drm/drm_fourcc.h +++ b/include/uapi/drm/drm_fourcc.h @@ -104,6 +104,15 @@ extern "C" { #define DRM_FORMAT_C4 fourcc_code('C', '4', ' ', ' ') /* [7:0] C0:C1 4:4 two pixels/byte */ #define DRM_FORMAT_C8 fourcc_code('C', '8', ' ', ' ') /* [7:0] C */ +/* 1 bpp Red (direct relationship between channel value and brightness) */ +#define DRM_FORMAT_R1 fourcc_code('R', '1', ' ', ' ') /* [7:0] R0:R1:R2:R3:R4:R5:R6:R7 1:1:1:1:1:1:1:1 eight pixels/byte */ + +/* 2 bpp Red (direct relationship between channel value and brightness) */ +#define DRM_FORMAT_R2 fourcc_code('R', '2', ' ', ' ') /* [7:0] R0:R1:R2:R3 2:2:2:2 four pixels/byte */ + +/* 4 bpp Red (direct relationship between channel value and brightness) */ +#define DRM_FORMAT_R4 fourcc_code('R', '4', ' ', ' ') /* [7:0] R0:R1 4:4 two pixels/byte */ + /* 8 bpp Red (direct relationship between channel value and brightness) */ #define DRM_FORMAT_R8 fourcc_code('R', '8', ' ', ' ') /* [7:0] R */ |