diff --git a/util/flv_tag.cpp b/util/flv_tag.cpp
index f595bbff..3be1f4e1 100644
--- a/util/flv_tag.cpp
+++ b/util/flv_tag.cpp
@@ -43,6 +43,31 @@ bool FLV::is_header(char * header){
   return true;
 }//FLV::is_header
 
+/// True if this media type requires init data.
+/// Will always return false if the tag type is not 0x08 or 0x09.
+/// Returns true for H263, AVC (H264), AAC.
+/// \todo Check if MP3 does or does not require init data...
+bool FLV::Tag::needsInitData(){
+  switch (data[0]){
+    case 0x09:
+      switch (data[11] & 0x0F){
+        case 2: return true; break;//H263 requires init data
+        case 7: return true; break;//AVC requires init data
+        default: return false; break;//other formats do not
+      }
+      break;
+    case 0x08:
+      switch (data[11] & 0xF0){
+        case 0x20: return false; break;//MP3 does not...? Unsure.
+        case 0xA0: return true; break;//AAC requires init data
+        case 0xE0: return false; break;//MP38kHz does not...?
+        default: return false; break;//other formats do not
+      }
+      break;
+  }
+  return false;//only audio/video can require init data
+}
+
 /// True if current tag is init data for this media type.
 bool FLV::Tag::isInitData(){
   switch (data[0]){
diff --git a/util/flv_tag.h b/util/flv_tag.h
index 2ad39673..1d7bbc41 100644
--- a/util/flv_tag.h
+++ b/util/flv_tag.h
@@ -22,6 +22,7 @@ namespace FLV {
       int len; ///< Actual length of tag.
       bool isKeyframe; ///< True if current tag is a video keyframe.
       char * data; ///< Pointer to tag buffer.
+      bool needsInitData(); ///< True if this media type requires init data.
       bool isInitData(); ///< True if current tag is init data for this media type.
       std::string tagType(); ///< Returns a std::string describing the tag in detail.
       unsigned int tagTime(); ///< Returns the 32-bit timestamp of this tag.