The distribution ships a .o_shipped file which must be symlinked by the build system before linking.
This was missed in version 14.2 of the DeckLink Desktop Video distribution.
The patch is a backport of the 15.* distributions.
--- a/desktopvideo/usr/src/blackmagic-io/Makefile
+++ b/desktopvideo/usr/src/blackmagic-io/Makefile
@@ -1,5 +1,5 @@
 #** -LICENSE-START-
-#** Copyright (c) 2009-2020 Blackmagic Design
+#** Copyright (c) 2009-2025 Blackmagic Design
 #**
 #** Permission is hereby granted, free of charge, to any person or organization
 #** obtaining a copy of the software and accompanying documentation covered by
@@ -28,6 +28,10 @@ KERNELRELEASE=`uname -r`
 KMOD_NAME=blackmagic-io
 EXTRA_CFLAGS +=  -DHAVE_INITFINI_ARRAY
 
+SRC_DIR := $(dir $(abspath $(firstword $(MAKEFILE_LIST))))
+BMIO_BINARY_O_SHIPPED := $(SRC_DIR)/blackmagic.o_shipped
+BMIO_BINARY_O := blackmagic.o
+
 $(KMOD_NAME)-objs := \
 	 bmio_client.o bmio_dev.o bmio_device.o bmio_driver.o bmio_serial.o bmio_export.o bmio_pci_ids.o bm_locks.o bm_mm.o bm_pci.o bm_util.o blackmagic.o
 
@@ -43,12 +47,15 @@ KERNELDIR ?= /lib/modules/$(KERNELRELEAS
 PWD       := $(shell pwd)
 LIB_TARGET_CMD = .blackmagic.o.cmd
 
-all: $(LIB_TARGET_CMD)
+all: $(LIB_TARGET_CMD) $(BMIO_BINARY_O)
 	$(MAKE) -C $(KERNELDIR) M=$(PWD)
 
 $(LIB_TARGET_CMD):
 	touch $@
 
+$(BMIO_BINARY_O):
+	ln -sf $(BMIO_BINARY_O_SHIPPED) $@
+
 clean:
 	rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions built-in.o Module.symvers Module.markers modules.order
 
--- a/desktopvideo/usr/src/blackmagic/Makefile
+++ b/desktopvideo/usr/src/blackmagic/Makefile
@@ -28,6 +28,10 @@ KERNELRELEASE=`uname -r`
 KMOD_NAME=blackmagic
 EXTRA_CFLAGS +=  -DHAVE_INITFINI_ARRAY
 
+SRC_DIR := $(dir $(abspath $(firstword $(MAKEFILE_LIST))))
+BMD_SUPPORT_BINARY_O_SHIPPED := $(SRC_DIR)/bmd-support.o_shipped
+BMD_SUPPORT_BINARY_O := bmd-support.o
+
 $(KMOD_NAME)-objs := \
 	 blackmagic_serial.o blackmagic_core.o blackmagic_lib.o blackmagic_dma.o blackmagic_gate.o bmd-support.o
 
@@ -40,12 +44,15 @@ KERNELDIR ?= /lib/modules/$(KERNELRELEAS
 PWD       := $(shell pwd)
 LIB_TARGET_CMD = .bmd-support.o.cmd
 
-all: $(LIB_TARGET_CMD)
+all: $(LIB_TARGET_CMD) $(BMD_SUPPORT_BINARY_O)
 	$(MAKE) -C $(KERNELDIR) M=$(PWD)
 
 $(LIB_TARGET_CMD):
 	touch $@
 
+$(BMD_SUPPORT_BINARY_O):
+	ln -sf $(BMD_SUPPORT_BINARY_O_SHIPPED) $@
+
 clean:
 	rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions built-in.o Module.symvers Module.markers modules.order