Fix dynamic loading of FFMPEG libraries.

Index: src/common/dynamic_library/dynamic_library.cpp
--- src/common/dynamic_library/dynamic_library.cpp.orig
+++ src/common/dynamic_library/dynamic_library.cpp
@@ -83,6 +83,9 @@ std::string DynamicLibrary::GetLibraryName(std::string
     } else {
         return fmt::format("{}{}.dylib", prefix, name);
     }
+#elif defined(__OpenBSD__)
+    auto prefix = name.starts_with("lib") ? "" : "lib";
+    return fmt::format("{}{}.so", prefix, name);
 #else
     auto prefix = name.starts_with("lib") ? "" : "lib";
     if (major >= 0 && minor >= 0) {
