--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dtx.h	Fri Jun 14 23:27:16 2024 +0000
@@ -0,0 +1,62 @@
+#ifndef __DTX
+#define __DTX
+
+#include "typedefs.h"
+
+
+#define PN_INIT_SEED (Longword)0x1091988L       /* initial seed for Comfort
+                                                 * noise pn-generator */
+
+#define CNINTPER    12                 /* inperpolation period of CN
+                                        * parameters */
+
+#define SPEECH      1
+#define CNIFIRSTSID 2
+#define CNICONT     3
+#define CNIBFI      4
+
+#define VALIDSID    11
+#define INVALIDSID  22
+#define GOODSPEECH  33
+#define UNUSABLE    44
+
+/*________________________________________________________________________
+ |                                                                        |
+ |                      Function Prototypes                               |
+ |________________________________________________________________________|
+*/
+
+void   avgCNHist(Longword pL_R0History[],
+                        Longword ppL_CorrHistory[OVERHANG][NP + 1],
+                        Longword *pL_AvgdR0,
+                        Longword pL_AvgdCorrSeq[]);
+
+  void   avgGsHistQntz(Longword pL_GsHistory[], Longword *pL_GsAvgd);
+
+  Shortword swComfortNoise(Shortword swVadFlag,
+                            Longword L_UnqntzdR0, Longword *pL_UnqntzdCorr);
+
+  Shortword getPnBits(int iBits, Longword *L_PnSeed);
+
+  Shortword gsQuant(Longword L_GsIn, Shortword swVoicingMode);
+
+  void   updateCNHist(Longword L_UnqntzdR0,
+                             Longword *pL_UnqntzdCorr,
+                             Longword pL_R0Hist[],
+                             Longword ppL_CorrHist[OVERHANG][NP + 1]);
+
+  void   lpcCorrQntz(Longword pL_CorrelSeq[],
+                            Shortword pswFinalRc[],
+                            int piVQCodewds[]);
+
+  Longword linInterpSid(Longword L_New, Longword L_Old, Shortword swDtxState);
+
+  Shortword linInterpSidShort(Shortword swNew,
+                                     Shortword swOld,
+                                     Shortword swDtxState);
+
+  void   rxInterpR0Lpc(Shortword *pswOldKs, Shortword *pswNewKs,
+                              Shortword swRxDTXState,
+                              Shortword swDecoMode, Shortword swFrameType);
+
+#endif