Hi Sam, On Sun, Jul 10, 2022 at 12:40 PM Sam Ravnborg <sam@xxxxxxxxxxxx> wrote: > On Fri, Jul 08, 2022 at 08:21:30PM +0200, Geert Uytterhoeven wrote: > > 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. > > > > Changes compared to v1: > > - SMPTE color LUT accuracy, > > - Factor out smpte color LUT, > > - Restructure patches, > > - Improve descriptions. > > - Store number of colors for indexed formats, > > - Add SMPTE pattern support for the C1 and C2 formats. > > > > Please refer to [2] for related Linux DRM patches and background > > information. > > > > Thanks for your comments! > > > > [1] "[PATCH libdrm 0/3] Add support for low-color frame buffer formats" > > https://lore.kernel.org/r/cover.1646683737.git.geert@xxxxxxxxxxxxxx > > [2] "[PATCH v3 00/10] drm: Add support for low-color frame buffer formats" > > https://lore.kernel.org/r/cover.1657294931.git.geert@xxxxxxxxxxxxxx > > > > Geert Uytterhoeven (10): > > util: Improve SMPTE color LUT accuracy > > util: Factor out and optimize C8 SMPTE color LUT > > [RFC] drm_fourcc: Add DRM_FORMAT_C[124] > > util: Add support for DRM_FORMAT_C[124] > > util: Store number of colors for indexed formats > > util: Add SMPTE pattern support for C4 format > > util: Add SMPTE pattern support for C1 format > > util: Add SMPTE pattern support for C2 format > > modetest: Add support for DRM_FORMAT_C[124] > > modetest: Add SMPTE pattern support for C4 format > > I have browsed the patches - everything looked good. > The parts with Floyd-Steinberg dithering did get less > attention as I do not know it. As a picture says more than 10000 words, I shared screenshots of modetest showing the SMPTE pattern in C1 (monochrome FS-dithered [1]), C2 (PenTile RG-GB FS-dithered [2]), and C4 ([3]). And Wikipedia[4] is your friend for the algorithm ;-) > But everything looked good and the series is: > > Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx> Thanks! [1] https://drive.google.com/file/d/1waJczErrIaEKRhBCCU1ynxRG8agpo0Xx/view?usp=sharing [2] https://drive.google.com/file/d/1g5O8XeacrjrC8rgaVENvR65YeI6QvmtO/view?usp=sharing [3] https://drive.google.com/file/d/1VIMqz_OkjJbbFS2OCX1O8GBm4bag6y2n/view?usp=sharing [4] https://en.wikipedia.org/wiki/Floyd%E2%80%93Steinberg_dithering Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
