The BO pitches are unconditionally set to the frame buffer pitch, for all planes. This is correct for semiplanar YUV formats, as they subsample chroma horizontally by two but combined U and V in a single plane, cancelling each other. For fully planar YUV formats, however, the horizontal subsampling need to be taken into account to compute the pitch. Fix it. Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> --- kms++/src/dumbframebuffer.cpp | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kms++/src/dumbframebuffer.cpp b/kms++/src/dumbframebuffer.cpp index 18f3f152943d..4c3c03164a90 100644 --- a/kms++/src/dumbframebuffer.cpp +++ b/kms++/src/dumbframebuffer.cpp @@ -42,6 +42,14 @@ DumbFramebuffer::DumbFramebuffer(Card& card, uint32_t width, uint32_t height, Pi struct drm_mode_create_dumb creq = drm_mode_create_dumb(); creq.width = width; creq.height = height / pi.ysub; + /* + * For fully planar YUV buffers, the chroma planes don't combine + * U and V components, their width must thus be divided by the + * horizontal subsampling factor. + */ + if (format_info.type == PixelColorType::YUV && + format_info.num_planes == 3) + creq.width /= pi.xsub; creq.bpp = pi.bitspp; r = drmIoctl(card.fd(), DRM_IOCTL_MODE_CREATE_DUMB, &creq); if (r) -- Regards, Laurent Pinchart
