Commit 91b0dc5147 for ffmpeg

commit 91b0dc51476c03c8c38f3184ddfbcd18e460c7ad
Author: Niklas Haas <git@haasn.dev>
Date:   Wed Oct 21 00:58:52 2026 +0200

    swscale/vulkan/ops: reject dithering of non-float values

    The dither offsets are added with a float addition, which is not valid
    for integer values.

    Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
    Signed-off-by: Niklas Haas <git@haasn.dev>

diff --git a/libswscale/vulkan/ops.c b/libswscale/vulkan/ops.c
index be3be0621b..8a84f7f865 100644
--- a/libswscale/vulkan/ops.c
+++ b/libswscale/vulkan/ops.c
@@ -1282,6 +1282,8 @@ static int add_ops_spirv(SwsContext *sws, VulkanPriv *p, FFVulkanOpsCtx *s,
             }
             break;
         case SWS_OP_DITHER: {
+            if (type_in != SWS_PIXEL_F32)
+                return AVERROR(ENOTSUP);
             const struct DitherData *d = &id->dither[oid->buf];
             int x_id = spi_OpCompositeExtract(spi, id->u32_type, gid, 0);
             int y_pos = spi_OpCompositeExtract(spi, id->u32_type, gid, 1);