Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 65183)
+++ /trunk/Config.kmk	(revision 65184)
@@ -3703,4 +3703,11 @@
 SDK_VBOX_VPX_INCS ?= $(SDK_VBOX_VPX_DEFAULT_INCS)
 SDK_VBOX_VPX_LIBS ?= $(PATH_STAGE_LIB)/VBox-libvpx$(VBOX_SUFF_LIB)
+
+ifdef VBOX_WITH_LIBOPUS
+SDK_VBOX_OPUS       = .
+SDK_VBOX_OPUS_DEFAULT_INCS := $(PATH_ROOT)/src/libs/libopus
+SDK_VBOX_OPUS_INCS ?= $(SDK_VBOX_OPUS_DEFAULT_INCS)
+SDK_VBOX_OPUS_LIBS ?= $(PATH_STAGE_LIB)/VBox-libopus$(VBOX_SUFF_LIB)
+endif
 
 #
Index: /trunk/src/VBox/Main/Makefile.kmk
===================================================================
--- /trunk/src/VBox/Main/Makefile.kmk	(revision 65183)
+++ /trunk/src/VBox/Main/Makefile.kmk	(revision 65184)
@@ -706,4 +706,11 @@
   VBoxC_SDKS += VBOX_VPX
 endif
+ifdef VBOX_WITH_AUDIO_VIDEOREC
+  ifdef VBOX_WITH_LIBOPUS
+   VBoxC_SDKS += VBOX_OPUS
+  else
+   $(error "VBox: No alternative for Opus when using audio support for video capturing yet")
+  endif
+endif
 ifdef VBOX_WITH_OPENSSL_FIPS
   VBoxC_SDKS += VBOX_OPENSSL2
Index: /trunk/src/libs/Makefile.kmk
===================================================================
--- /trunk/src/libs/Makefile.kmk	(revision 65183)
+++ /trunk/src/libs/Makefile.kmk	(revision 65184)
@@ -85,4 +85,12 @@
   endif
  endif
+
+ # Opus for audio encoding video capture
+ if defined(VBOX_WITH_LIBOPUS) && !defined(VBOX_ONLY_DOCS) && !defined(VBOX_WITH_SDK) \
+   && ("$(SDK_VBOX_OPUS_INCS)" == "$(SDK_VBOX_OPUS_DEFAULT_INCS)")
+  if1of ($(KBUILD_TARGET), linux)
+   include $(PATH_SUB_CURRENT)/libopus/Makefile.kmk
+  endif
+ endif
 endif