Hi, On 28/03/2025 00:34, Laurent Pinchart wrote:
Hi Tomi,Thank you for the patch. On Wed, Mar 26, 2025 at 03:22:45PM +0200, Tomi Valkeinen wrote:Add two new pixel formats: DRM_FORMAT_XV15 ("XV15") DRM_FORMAT_XV20 ("XV20") The formats are 2 plane 10 bit per component YCbCr, with the XV15 2x2 subsampled whereas XV20 is 2x1 subsampled. Reviewed-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org> Signed-off-by: Tomi Valkeinen <tomi.valkei...@ideasonboard.com> --- drivers/gpu/drm/drm_fourcc.c | 6 ++++++ include/uapi/drm/drm_fourcc.h | 8 ++++++++ 2 files changed, 14 insertions(+) diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c index 2f5781f5dcda..e101d1b99aeb 100644 --- a/drivers/gpu/drm/drm_fourcc.c +++ b/drivers/gpu/drm/drm_fourcc.c @@ -346,6 +346,12 @@ const struct drm_format_info *__drm_format_info(u32 format) { .format = DRM_FORMAT_P030, .depth = 0, .num_planes = 2, .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true}, + { .format = DRM_FORMAT_XV15, .depth = 0, .num_planes = 2, + .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 }, + .hsub = 2, .vsub = 2, .is_yuv = true }, + { .format = DRM_FORMAT_XV20, .depth = 0, .num_planes = 2, + .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 }, + .hsub = 2, .vsub = 1, .is_yuv = true },It appears we can never have too much (or enough) documentation, as reading the format info documentation leaves me with unanswered questions. Looking at drm_format_info_min_pitch(): uint64_t drm_format_info_min_pitch(const struct drm_format_info *info, int plane, unsigned int buffer_width) { if (!info || plane < 0 || plane >= info->num_planes) return 0; return DIV_ROUND_UP_ULL((u64)buffer_width * info->char_per_block[plane], drm_format_info_block_width(info, plane) * drm_format_info_block_height(info, plane)); } For the first plane, the function will return `buffer_width * 4 / 3` (rouding up), which I think is right. For the second plane, it will return `buffer_width * 8 / 3`, which I believe is wrong as the format is subsampled by a factor 2 horizontally. It seems that either char_per_block and block_w need to take horizontal subsampling into account (and therefore be 8 and 6 for the second plane), or drm_format_info_min_pitch() should consider .hsub. Or there's something else I'm missing :-)
The buffer_width is already divided by the hsub, in drm_format_info_plane_width().
};unsigned int i;diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h index 81202a50dc9e..1247b814bd66 100644 --- a/include/uapi/drm/drm_fourcc.h +++ b/include/uapi/drm/drm_fourcc.h @@ -304,6 +304,14 @@ extern "C" { #define DRM_FORMAT_RGB565_A8 fourcc_code('R', '5', 'A', '8') #define DRM_FORMAT_BGR565_A8 fourcc_code('B', '5', 'A', '8')+/*+ * 2 plane 10 bit per component YCrCb + * index 0 = Y plane, [31:0] x:Y2:Y1:Y0 2:10:10:10 little endian + * index 1 = Cb:Cr plane, [63:0] x:Cr2:Cb2:Cr1:x:Cb1:Cr0:Cb0 2:10:10:10:2:10:10:10 little endianI believe this is right, but I have a hard time validating it, as I think the corresponding figures in UG1085 are incorrect (they show a 8bpp format as far as I can tell). Do I assume correctly that you've tested the formats ?
Yes. kms++'s master branch has support for all the formats in this series. Tomi
