git-svn-id: http://webrtc.googlecode.com/svn/trunk@4 4adac7df-926f-26a2-2b94-8c16560cd09d

modules/audio_coding/codecs/iLBC/main/source/refiner.c

@@ -0,0 +1,155 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+/******************************************************************
+
+ iLBC Speech Coder ANSI-C Source Code
+
+ WebRtcIlbcfix_Refiner.c
+
+******************************************************************/
+
+#include "defines.h"
+#include "constants.h"
+#include "enh_upsample.h"
+#include "my_corr.h"
+
+/*----------------------------------------------------------------*
+ * find segment starting near idata+estSegPos that has highest
+ * correlation with idata+centerStartPos through
+ * idata+centerStartPos+ENH_BLOCKL-1 segment is found at a
+ * resolution of ENH_UPSO times the original of the original
+ * sampling rate
+ *---------------------------------------------------------------*/
+
+void WebRtcIlbcfix_Refiner(
+    iLBC_Dec_Inst_t *iLBCdec_inst,
+    /* (i) Decoder state */
+    WebRtc_Word16 *updStartPos, /* (o) updated start point (Q-2) */
+    WebRtc_Word16 *idata,   /* (i) original data buffer */
+    WebRtc_Word16 idatal,   /* (i) dimension of idata */
+    WebRtc_Word16 centerStartPos, /* (i) beginning center segment */
+    WebRtc_Word16 estSegPos,  /* (i) estimated beginning other segment (Q-2) */
+    WebRtc_Word16 *surround,  /* (i/o) The contribution from this sequence
+                                           summed with earlier contributions */
+    WebRtc_Word16 gain    /* (i) Gain to use for this sequence */
+                           ){
+  WebRtc_Word16 estSegPosRounded,searchSegStartPos,searchSegEndPos,corrdim;
+  WebRtc_Word16 tloc,tloc2,i,st,en,fraction;
+
+  WebRtc_Word32 maxtemp, scalefact;
+  WebRtc_Word16 *filtStatePtr, *polyPtr;
+  /* Stack based */
+  WebRtc_Word16 filt[7];
+  WebRtc_Word32 corrVecUps[ENH_CORRDIM*ENH_UPS0];
+  WebRtc_Word32 corrVecTemp[ENH_CORRDIM];
+  WebRtc_Word16 vect[ENH_VECTL];
+  WebRtc_Word16 corrVec[ENH_CORRDIM];
+
+  /* The input parameter iLBCdec_inst is unused unless using scratch memory */
+  iLBCdec_inst = iLBCdec_inst;
+
+  /* defining array bounds */
+
+  estSegPosRounded=WEBRTC_SPL_RSHIFT_W16((estSegPos - 2),2);
+
+  searchSegStartPos=estSegPosRounded-ENH_SLOP;
+
+  if (searchSegStartPos<0) {
+    searchSegStartPos=0;
+  }
+  searchSegEndPos=estSegPosRounded+ENH_SLOP;
+
+  if(searchSegEndPos+ENH_BLOCKL >= idatal) {
+    searchSegEndPos=idatal-ENH_BLOCKL-1;
+  }
+  corrdim=searchSegEndPos-searchSegStartPos+1;
+
+  /* compute upsampled correlation and find
+     location of max */
+
+  WebRtcIlbcfix_MyCorr(corrVecTemp,idata+searchSegStartPos,
+                       (WebRtc_Word16)(corrdim+ENH_BLOCKL-1),idata+centerStartPos,ENH_BLOCKL);
+
+  /* Calculate the rescaling factor for the correlation in order to
+     put the correlation in a WebRtc_Word16 vector instead */
+  maxtemp=WebRtcSpl_MaxAbsValueW32(corrVecTemp, (WebRtc_Word16)corrdim);
+
+  scalefact=WebRtcSpl_GetSizeInBits(maxtemp)-15;
+
+  if (scalefact>0) {
+    for (i=0;i<corrdim;i++) {
+      corrVec[i]=(WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(corrVecTemp[i], scalefact);
+    }
+  } else {
+    for (i=0;i<corrdim;i++) {
+      corrVec[i]=(WebRtc_Word16)corrVecTemp[i];
+    }
+  }
+  /* In order to guarantee that all values are initialized */
+  for (i=corrdim;i<ENH_CORRDIM;i++) {
+    corrVec[i]=0;
+  }
+
+  /* Upsample the correlation */
+  WebRtcIlbcfix_EnhUpsample(corrVecUps,corrVec);
+
+  /* Find maximum */
+  tloc=WebRtcSpl_MaxIndexW32(corrVecUps, (WebRtc_Word16) (ENH_UPS0*corrdim));
+
+  /* make vector can be upsampled without ever running outside
+     bounds */
+  *updStartPos = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16(searchSegStartPos,4) + tloc + 4;
+
+  tloc2 = WEBRTC_SPL_RSHIFT_W16((tloc+3), 2);
+
+  st=searchSegStartPos+tloc2-ENH_FL0;
+
+  /* initialize the vector to be filtered, stuff with zeros
+     when data is outside idata buffer */
+  if(st<0){
+    WebRtcSpl_MemSetW16(vect, 0, (WebRtc_Word16)(-st));
+    WEBRTC_SPL_MEMCPY_W16(&vect[-st], idata, (ENH_VECTL+st));
+  }
+  else{
+    en=st+ENH_VECTL;
+
+    if(en>idatal){
+      WEBRTC_SPL_MEMCPY_W16(vect, &idata[st],
+                            (ENH_VECTL-(en-idatal)));
+      WebRtcSpl_MemSetW16(&vect[ENH_VECTL-(en-idatal)], 0,
+                          (WebRtc_Word16)(en-idatal));
+    }
+    else {
+      WEBRTC_SPL_MEMCPY_W16(vect, &idata[st], ENH_VECTL);
+    }
+  }
+  /* Calculate which of the 4 fractions to use */
+  fraction=(WebRtc_Word16)WEBRTC_SPL_MUL_16_16(tloc2,ENH_UPS0)-tloc;
+
+  /* compute the segment (this is actually a convolution) */
+
+  filtStatePtr = filt + 6;
+  polyPtr = (WebRtc_Word16*)WebRtcIlbcfix_kEnhPolyPhaser[fraction];
+  for (i=0;i<7;i++) {
+    *filtStatePtr-- = *polyPtr++;
+  }
+
+  WebRtcSpl_FilterMAFastQ12(
+      &vect[6], vect, filt,
+      ENH_FLO_MULT2_PLUS1, ENH_BLOCKL);
+
+  /* Add the contribution from this vector (scaled with gain) to the total surround vector */
+  WebRtcSpl_AddAffineVectorToVector(
+      surround, vect, gain,
+      (WebRtc_Word32)32768, 16, ENH_BLOCKL);
+
+  return;
+}