diff --git a/README.md b/README.md
index 4432e28..290cabb 100644
--- a/README.md
+++ b/README.md
@@ -79,6 +79,10 @@ The following projects have been consulted for pdf2htmlEX:
 
 ## Contact
 
+Suggestions and questions are welcome.
+
+Please read the FAQ(https://github.com/coolwanglu/pdf2htmlEX/wiki/FAQ) beforehand.
+
 * Lu Wang <coolwanglu@gmail.com>
 
 ### Special Thanks
diff --git a/TODO b/TODO
index 0ea638e..f8905d8 100644
--- a/TODO
+++ b/TODO
@@ -2,8 +2,6 @@ disable annotation
 
 valgrind
 
-re-encoded only used glyphs
-
 detect duplicate base fonts when embedding
 
 take care of spaces (simulate by <span>)
diff --git a/src/HTMLRenderer/text.cc b/src/HTMLRenderer/text.cc
index 90873f9..9372a36 100644
--- a/src/HTMLRenderer/text.cc
+++ b/src/HTMLRenderer/text.cc
@@ -175,8 +175,11 @@ void HTMLRenderer::embed_font(const path & filepath, GfxFont * font, FontInfo &
 
     info.use_tounicode = ((suffix == ".ttf") || (font->isCIDFont()) || (param->always_apply_tounicode));
 
+
     if(!get_metric_only)
     {
+        const char * used_map = font_preprocessor.get_code_map(hash_ref(font->getID()));
+
         /*
          * Step 1
          * dump the font file directly from the font descriptor and put the glyphs into the correct slots
@@ -217,8 +220,6 @@ void HTMLRenderer::embed_font(const path & filepath, GfxFont * font, FontInfo &
 
                 memset(cur_mapping2, 0, 256 * sizeof(char*));
 
-                const char * used_map = font_preprocessor.get_code_map(hash_ref(font->getID()));
-
                 for(int i = 0; i < 256; ++i)
                 {
                     if(!used_map[i]) continue;
@@ -293,6 +294,9 @@ void HTMLRenderer::embed_font(const path & filepath, GfxFont * font, FontInfo &
             int max_key = maxcode;
             for(int i = 0; i <= maxcode; ++i)
             {
+                if(!used_map[i])
+                    continue;
+
                 if((suffix != ".ttf") && (font_8bit != nullptr) && (font_8bit->getCharName(i) == nullptr))
                 {
                     continue;