Add audio to 3DS banner

CMakeLists.txt

@@ -917,16 +917,23 @@ if(NINTENDO_3DS)
   set(APP_AUTHOR      "Diasurgical Team")
   set(APP_ICON        "${PROJECT_SOURCE_DIR}/Packaging/ctr/icon.png")
   set(APP_BANNER      "${PROJECT_SOURCE_DIR}/Packaging/ctr/banner.png")
-  set(APP_AUDIO       "${PROJECT_SOURCE_DIR}/Packaging/ctr/audio_silent.wav")
+  set(APP_AUDIO       "${PROJECT_SOURCE_DIR}/Packaging/ctr/banner_audio.wav")
   set(APP_RSF         "${PROJECT_SOURCE_DIR}/Packaging/ctr/template.rsf")
   set(APP_ROMFS       "${CMAKE_BINARY_DIR}/romfs")
   set(APP_ROMFS_FILES
     "${PROJECT_SOURCE_DIR}/Packaging/resources/CharisSILB.ttf"
     "${PROJECT_SOURCE_DIR}/Packaging/resources/devilutionx.mpq")
+  set(APP_VERSION ${PROJECT_VERSION})
+
+  find_program(FFMPEG ffmpeg)
+  if(FFMPEG)
+    execute_process(COMMAND ${FFMPEG} -y -ss 3.3 -t 3 -i "${PROJECT_SOURCE_DIR}/Packaging/resources/shareware-startup.wav" -af "afade=t=in:st=0:d=0.1,afade=t=out:st=2.9:d=0.1" ${APP_AUDIO})
+  endif()
+
   file(MAKE_DIRECTORY ${APP_ROMFS})
   file(COPY ${APP_ROMFS_FILES}
      DESTINATION ${APP_ROMFS})
-  set(APP_VERSION ${PROJECT_VERSION})
+
   include(Tools3DS)
   add_3dsx_target(${BIN_TARGET})
   add_cia_target(${BIN_TARGET} ${APP_RSF} ${APP_BANNER} ${APP_AUDIO} ${APP_ROMFS})