--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sp_enc.c	Fri Jun 14 23:27:16 2024 +0000
@@ -0,0 +1,406 @@
+/***************************************************************************
+ *
+ *   File Name:  sp_enc.c
+ *
+ *   Purpose:  Contains speech encoder function.  Calls are made to the
+ *      frame-based encoding functions (see sp_frm.c), and the subframe-
+ *      based encoding function (see sp_sfrm.c)
+ *
+ *      Functions in this file (only 1)
+ *      speechEncoder()
+ *
+ **************************************************************************/
+/*_________________________________________________________________________
+ |                                                                         |
+ |                              Include Files                              |
+ |_________________________________________________________________________|
+*/
+
+#include "mathhalf.h"
+#include "mathdp31.h"
+#include "sp_rom.h"
+#include "sp_dec.h"
+#include "sp_frm.h"
+#include "sp_sfrm.h"
+#include "sp_enc.h"
+#include "host.h"
+#include "vad.h"
+
+/*_________________________________________________________________________
+ |                                                                         |
+ |                              Local Defines                              |
+ |_________________________________________________________________________|
+*/
+
+#define CG_INT_MACS       6            /* Number of Multiply-Accumulates in */
+                                       /* one interpolation                 */
+#define ASCALE       0x0800
+#define LMAX            142            /* largest lag (integer sense) */
+#define LSMAX           (LMAX+ CG_INT_MACS/2)   /* Lag Search Array Length */
+#define NUM_CLOSED        3            /* Maximum number of lags searched */
+                                      /* in closed loop.                 */
+
+#define LPCSTARTINDEX     25           /* Where the LPC analysis window
+                                        * starts */
+#define INBUFFSZ          LPCSTARTINDEX + A_LEN /* Input buffer size  */
+#define NUMSTARTUPSMP     INBUFFSZ - F_LEN      /* Number of samples needed */
+                                                /* at start up              */
+#define NUMSTARTUPSMP_P1  INBUFFSZ - F_LEN + 1
+#define HPFSHIFT          1            /* no right shifts high pass shifts
+                                        * speech */
+
+/*_________________________________________________________________________
+ |                                                                         |
+ |                     State variables (globals)                           |
+ |_________________________________________________________________________|
+*/
+
+Shortword swOldR0;
+Shortword swOldR0Index;
+
+struct NormSw psnsWSfrmEngSpace[2 * N_SUB];
+
+Shortword pswHPFXState[4];
+Shortword pswHPFYState[8];
+Shortword pswOldFrmKs[NP];
+Shortword pswOldFrmAs[NP];
+Shortword pswOldFrmSNWCoefs[NP];
+Shortword pswWgtSpeechSpace[F_LEN + LMAX + CG_INT_MACS / 2];
+
+Shortword pswSpeech[INBUFFSZ];         /* input speech */
+
+Shortword swPtch = 1;
+
+/*_________________________________________________________________________
+ |                                                                         |
+ |                         Global DTX variables                            |
+ |_________________________________________________________________________|
+*/
+
+Shortword swTxGsHistPtr = 0;
+
+Shortword pswCNVSCode1[N_SUB],
+          pswCNVSCode2[N_SUB],
+          pswCNGsp0Code[N_SUB],
+          pswCNLpc[3],
+          swCNR0;
+
+
+extern Longword pL_GsHist[];
+extern LongwordRom ppLr_gsTable[4][32];
+
+/***************************************************************************
+ *
+ *   FUNCTION NAME: speechEncoder
+ *
+ *   PURPOSE:
+ *
+ *     Performs GSM half-rate speech encoding on frame basis (160 samples).
+ *
+ *   INPUTS:
+ *
+ *     pswSpeechIn[0:159] - input speech samples, 160 new samples per frame
+ *
+ *   OUTPUTS:
+ *
+ *     pswFrmCodes[0:19] - output parameters, 18 speech parameters plus
+ *                         VAD and SP flags
+ *
+ *   RETURN VALUE:
+ *
+ *     None
+ *
+ *   IMPLEMENTATION:
+ *
+ *     n/a
+ *
+ *   REFERENCES: Sub-clause 4.1 of GSM Recomendation 06.20
+ *
+ *   KEYWORDS: speechcoder, analysis
+ *
+ *************************************************************************/
+
+void   speechEncoder(Shortword pswSpeechIn[], Shortword pswFrmCodes[])
+{
+
+/*_________________________________________________________________________
+ |                                                                         |
+ |                            Static Variables                             |
+ |_________________________________________________________________________|
+*/
+
+  /* 1st point in analysis window */
+  static Shortword *pswLpcStart = &pswSpeech[LPCSTARTINDEX];
+
+  /* 1st point of new frame other than 1st */
+  static Shortword *pswNewSpeech = &pswSpeech[NUMSTARTUPSMP];
+
+  /* sample 0 of weighted speech */
+  static Shortword *pswWgtSpeech = &pswWgtSpeechSpace[LSMAX];
+
+  static struct NormSw *psnsWSfrmEng = &psnsWSfrmEngSpace[N_SUB];
+
+/*_________________________________________________________________________
+ |                                                                         |
+ |                            Automatic Variables                          |
+ |_________________________________________________________________________|
+*/
+
+  int    iVoicing,                     /* bitAlloc */
+         iR0,                          /* bitAlloc and aflat */
+         piVq[3],                      /* bitAlloc */
+         iSi,                          /* bitAlloc */
+         piLagCode[N_SUB],             /* bitAlloc */
+         piVSCode1[N_SUB],             /* bitAlloc */
+         piVSCode2[N_SUB],             /* bitAlloc */
+         piGsp0Code[N_SUB];            /* bitAlloc */
+
+  short int siUVCode,
+         siSi,
+         i,
+         j;
+
+  Shortword swR0,
+         pswLagCode[N_SUB],
+         pswVSCode1[N_SUB],
+         pswVSCode2[N_SUB],
+         pswGsp0Code[N_SUB],
+        *pswLagListPtr,
+         pswFrmKs[NP],
+         pswFrmAs[NP],
+         pswFrmSNWCoefs[NP],
+         pswLagList[N_SUB * NUM_CLOSED],
+         pswNumLagList[N_SUB],
+         pswPitchBuf[N_SUB],
+         pswHNWCoefBuf[N_SUB],
+         ppswSNWCoefAs[N_SUB][NP],
+         ppswSynthAs[N_SUB][NP];
+
+  Shortword swSP,
+         pswVadLags[4],                /* VAD Parameters */
+         swVadFlag;                    /* flag indicating voice activity
+                                        * detector state.  1 = speech or
+                                        * speech/signal present */
+  struct NormSw
+         psnsSqrtRs[N_SUB];
+
+/*_________________________________________________________________________
+ |                                                                         |
+ |                              Executable Code                            |
+ |_________________________________________________________________________|
+*/
+
+  /* Speech frame processing     */
+  /* High pass filter the speech */
+  /* ---------------------------- */
+
+  filt4_2nd(psrHPFCoefs, pswSpeechIn,
+            pswHPFXState, pswHPFYState, F_LEN, HPFSHIFT);
+
+  /* copy high passed filtered speech into encoder's speech buff */
+  /*-------------------------------------------------------------*/
+
+  for (i = 0; i < F_LEN; i++)
+    pswNewSpeech[i] = pswSpeechIn[i];
+
+
+
+
+  /* Calculate and quantize LPC coefficients */
+  /* --------------------------------------- */
+
+  aflat(pswLpcStart, &iR0, pswFrmKs, piVq,
+        swPtch, &swVadFlag, &swSP);
+
+
+  /* Lookup frame energy r0 */
+  /* ---------------------- */
+
+  swR0 = psrR0DecTbl[iR0 * 2];         /* lookupR0 */
+
+  /* Generate the direct form coefs */
+  /* ------------------------------ */
+
+  if (!rcToADp(ASCALE, pswFrmKs, pswFrmAs))
+  {
+
+    getNWCoefs(pswFrmAs, pswFrmSNWCoefs);
+  }
+  else
+  {
+
+    for (i = 0; i < NP; i++)
+    {
+      pswFrmKs[i] = pswOldFrmKs[i];
+      pswFrmAs[i] = pswOldFrmAs[i];
+      pswFrmSNWCoefs[i] = pswOldFrmSNWCoefs[i];
+    }
+  }
+
+  /* Interpolate, or otherwise get sfrm reflection coefs */
+  /* --------------------------------------------------- */
+
+  getSfrmLpcTx(swOldR0, swR0,
+               pswOldFrmKs, pswOldFrmAs,
+               pswOldFrmSNWCoefs,
+               pswFrmKs, pswFrmAs,
+               pswFrmSNWCoefs,
+               pswSpeech,
+               &siSi,
+               psnsSqrtRs,
+               ppswSynthAs, ppswSNWCoefAs);
+
+  /* loose once bitAlloc done */
+  iSi = siSi;
+
+  /* Weight the entire speech frame */
+  /* ------------------------------ */
+
+  weightSpeechFrame(pswSpeech, ppswSynthAs[0], ppswSNWCoefAs[0],
+                    pswWgtSpeechSpace);
+
+  /* Perform open-loop lag search, get harmonic-noise-weighting parameters */
+  /* --------------------------------------------------------------------- */
+
+  openLoopLagSearch(&pswWgtSpeechSpace[LSMAX],
+                    swOldR0Index,
+                    (Shortword) iR0,
+                    &siUVCode,
+                    pswLagList,
+                    pswNumLagList,
+                    pswPitchBuf,
+                    pswHNWCoefBuf,
+                    &psnsWSfrmEng[0],
+                    pswVadLags,
+                    swSP);
+
+  iVoicing = siUVCode;
+
+
+  /* Using open loop LTP data to calculate swPtch */      /* DTX mode */
+  /* parameter                                    */      /* DTX mode */
+  /* -------------------------------------------- */      /* DTX mode */
+  
+  periodicity_update(pswVadLags, &swPtch);                /* DTX mode */
+
+
+  /* Subframe processing loop */
+  /* ------------------------ */
+
+  pswLagListPtr = pswLagList;
+
+  for (giSfrmCnt = 0; giSfrmCnt < N_SUB; giSfrmCnt++)
+  {
+
+    if (swSP == 0)                                        /* DTX mode */
+    {                                                     /* DTX mode */
+      pswVSCode1[giSfrmCnt] = pswCNVSCode1[giSfrmCnt];    /* DTX mode */
+      pswVSCode2[giSfrmCnt] = pswCNVSCode2[giSfrmCnt];    /* DTX mode */
+      pswGsp0Code[giSfrmCnt] = pswCNGsp0Code[giSfrmCnt];  /* DTX mode */
+    }                                                     /* DTX mode */
+
+    sfrmAnalysis(&pswWgtSpeech[giSfrmCnt * S_LEN],
+                 siUVCode,
+                 psnsSqrtRs[giSfrmCnt],
+                 ppswSNWCoefAs[giSfrmCnt],
+                 pswLagListPtr,
+                 pswNumLagList[giSfrmCnt],
+                 pswPitchBuf[giSfrmCnt],
+                 pswHNWCoefBuf[giSfrmCnt],
+                 &pswLagCode[giSfrmCnt], &pswVSCode1[giSfrmCnt],
+                 &pswVSCode2[giSfrmCnt], &pswGsp0Code[giSfrmCnt],
+                 swSP);
+
+    pswLagListPtr = &pswLagListPtr[pswNumLagList[giSfrmCnt]];
+
+  }
+
+
+  /* copy comfort noise parameters, */                     /* DTX mode */
+  /* update GS history              */                     /* DTX mode */
+  /* ------------------------------ */                     /* DTX mode */
+
+  if (swSP == 0)                                           /* DTX mode */
+  {                                                        /* DTX mode */
+
+    /* copy comfort noise frame parameter */               /* DTX mode */
+    /* ---------------------------------- */               /* DTX mode */
+  
+    iR0 = swCNR0; /* quantized R0 index */                 /* DTX mode */
+    for (i=0; i < 3; i++)                                  /* DTX mode */
+      piVq[i] = pswCNLpc[i];                               /* DTX mode */
+
+  }                                                        /* DTX mode */
+  else                                                     /* DTX mode */
+  {                                                        /* DTX mode */
+      
+    /* if swSP != 0, then update the GS history */         /* DTX mode */
+    /* -----------------------------------------*/         /* DTX mode */
+
+    for (i=0; i < N_SUB; i++){                             /* DTX mode */
+      pL_GsHist[swTxGsHistPtr] =                           /* DTX mode */
+        ppLr_gsTable[siUVCode][pswGsp0Code[i]];            /* DTX mode */
+      swTxGsHistPtr++;                                     /* DTX mode */
+      if (swTxGsHistPtr > ((OVERHANG-1)*N_SUB)-1)          /* DTX mode */
+        swTxGsHistPtr=0;                                   /* DTX mode */
+    }                                                      /* DTX mode */
+
+  }                                                        /* DTX mode */
+
+
+  /* End of frame processing, update frame based parameters */
+  /* ------------------------------------------------------ */
+
+  for (i = 0; i < N_SUB; i++)
+  {
+    piLagCode[i] = pswLagCode[i];
+    piVSCode1[i] = pswVSCode1[i];
+    piVSCode2[i] = pswVSCode2[i];
+    piGsp0Code[i] = pswGsp0Code[i];
+  }
+
+  swOldR0Index = (Shortword) iR0;
+  swOldR0 = swR0;
+
+  for (i = 0; i < NP; i++)
+  {
+    pswOldFrmKs[i] = pswFrmKs[i];
+    pswOldFrmAs[i] = pswFrmAs[i];
+    pswOldFrmSNWCoefs[i] = pswFrmSNWCoefs[i];
+  }
+
+  /* Insert SID Codeword */                                /* DTX mode */
+  /* ------------------- */                                /* DTX mode */
+
+  if (swSP == 0)                                           /* DTX mode */ 
+  {                                                        /* DTX mode */
+    iVoicing = 0x0003;            /* 2 bits */             /* DTX mode */
+    iSi = 0x0001;                 /* 1 bit  */             /* DTX mode */
+    for (i=0; i < N_SUB; i++)                              /* DTX mode */
+    {                                                      /* DTX mode */
+      piVSCode1[i] =  0x01ff;     /* 9 bits */             /* DTX mode */
+      piGsp0Code[i] = 0x001f;     /* 5 bits */             /* DTX mode */
+    }
+    piLagCode[0] = 0x00ff;        /* 8 bits */             /* DTX mode */
+    piLagCode[1] = 0x000f;        /* 4 bits */             /* DTX mode */
+    piLagCode[2] = 0x000f;        /* 4 bits */             /* DTX mode */
+    piLagCode[3] = 0x000f;        /* 4 bits */             /* DTX mode */
+  }                                                        /* DTX mode */
+
+
+  /* Generate encoded parameter array */
+  /* -------------------------------- */
+
+  fillBitAlloc(iVoicing, iR0, piVq, iSi, piLagCode,
+               piVSCode1, piVSCode2,
+               piGsp0Code, swVadFlag, swSP, pswFrmCodes);
+
+
+  /* delay the input speech by 1 frame */
+  /*-----------------------------------*/
+
+  for (i = 0, j = F_LEN; j < INBUFFSZ; i++, j++)
+  {
+    pswSpeech[i] = pswSpeech[j];
+  }
+}