ffmpeg: Fix libx264 and libx265 description (#3334)

packages/f/ffmpeg/xmake.lua

@@ -37,8 +37,8 @@ package("ffmpeg")
     add_configs("zlib",             {description = "Enable zlib compression library.", default = false, type = "boolean"})
     add_configs("lzma",             {description = "Enable liblzma compression library.", default = false, type = "boolean"})
     add_configs("bzlib",            {description = "Enable bzlib compression library.", default = false, type = "boolean"})
-    add_configs("libx264",          {description = "Enable libx264 decoder.", default = false, type = "boolean"})
-    add_configs("libx265",          {description = "Enable libx265 decoder.", default = false, type = "boolean"})
+    add_configs("libx264",          {description = "Enable libx264 encoder.", default = false, type = "boolean"})
+    add_configs("libx265",          {description = "Enable libx265 encoder.", default = false, type = "boolean"})
     add_configs("iconv",            {description = "Enable libiconv library.", default = false, type = "boolean"})
     add_configs("vaapi",            {description = "Enable vaapi library.", default = false, type = "boolean"})
     add_configs("vdpau",            {description = "Enable vdpau library.", default = false, type = "boolean"})