Brightness (Linux): fix compatibility for ddcutil 2.0

Author: CarterLi

src/detection/brightness/brightness_linux.c

@@ -90,8 +90,15 @@ static const char* detectWithBacklight(FFlist* result)
 #include "common/library.h"
 #include "util/mallocHelper.h"
 
+#include <ddcutil_status_codes.h>
+#include <ddcutil_macros.h>
 #include <ddcutil_c_api.h>
 
+// Try to be compatible with ddcutil 2.0
+#if DDCUTIL_VMAJOR >= 2
+double ddca_set_default_sleep_multiplier(double multiplier); // ddcutil 1.4
+#endif
+
 static const char* detectWithDdcci(FFBrightnessOptions* options, FFlist* result)
 {
     FF_LIBRARY_LOAD(libddcutil, &instance.config.libDdcutil, "dlopen ddcutil failed", "libddcutil" FF_LIBRARY_EXTENSION, 5);
@@ -100,11 +107,14 @@ static const char* detectWithDdcci(FFBrightnessOptions* options, FFlist* result)
     FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_get_any_vcp_value_using_explicit_type)
     FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_free_any_vcp_value)
     FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_close_display)
-    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_set_sleep_multiplier)
     libddcutil = NULL; // Don't dlclose libddcutil. See https://github.com/rockowitz/ddcutil/issues/330
 
+    __typeof__(&ddca_set_default_sleep_multiplier) ffddca_set_default_sleep_multiplier = dlsym(libddcutil, "ddca_set_default_sleep_multiplier");
+    if (ffddca_set_default_sleep_multiplier)
+        ffddca_set_default_sleep_multiplier(options->ddcciSleep / 40.0);
+
     FF_AUTO_FREE DDCA_Display_Info_List* infoList = NULL;
-    if (__builtin_expect(ffddca_get_display_info_list2(false, &infoList) < 0, 0))
+    if (ffddca_get_display_info_list2(false, &infoList) < 0)
         return "ddca_get_display_info_list2(false, &infoList) failed";
 
     if (infoList->ct == 0)
@@ -117,8 +127,6 @@ static const char* detectWithDdcci(FFBrightnessOptions* options, FFlist* result)
         DDCA_Display_Handle handle;
         if (ffddca_open_display2(display->dref, false, &handle) >= 0)
         {
-            ffddca_set_sleep_multiplier(options->ddcciSleep / 40.0); // As of ddcutil 1.5, it sets the sleep multiplier for open display on the current thread
-
             DDCA_Any_Vcp_Value* vcpValue = NULL;
             if (ffddca_get_any_vcp_value_using_explicit_type(handle, 0x10 /*brightness*/, DDCA_NON_TABLE_VCP_VALUE, &vcpValue) >= 0)
             {