sequence callback function (#25)

* seq callback function

* bug fix

* changing some params for callback

* review comments

* switch case

* fixing minor border cases

[ROCm/rocdecode commit: 47ede638a3]

projects/rocdecode/src/parser/hevc_parser.h

@@ -819,4 +819,7 @@ private:
      * \return Returns pointer to the allocated memory for <tt>SliceHeaderData</tt>
      */
     SliceHeaderData* AllocSliceHeader();
+
+    // functions to fill structures for callback functions
+    void FillSeqCallbackFn(SpsData* sps_data);
 };