1 files changed, 89 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/cb_update_best_index.c b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/cb_update_best_index.c
new file mode 100644
index 0000000000..d6fa4d93d4
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/cb_update_best_index.c
@@ -0,0 +1,89 @@
+/*
+ *  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_CbUpdateBestIndex.c
+
+******************************************************************/
+
+#include "modules/audio_coding/codecs/ilbc/cb_update_best_index.h"
+
+#include "modules/audio_coding/codecs/ilbc/constants.h"
+#include "modules/audio_coding/codecs/ilbc/defines.h"
+
+void WebRtcIlbcfix_CbUpdateBestIndex(
+    int32_t CritNew,    /* (i) New Potentially best Criteria */
+    int16_t CritNewSh,   /* (i) Shift value of above Criteria */
+    size_t IndexNew,   /* (i) Index of new Criteria */
+    int32_t cDotNew,    /* (i) Cross dot of new index */
+    int16_t invEnergyNew,  /* (i) Inversed energy new index */
+    int16_t energyShiftNew,  /* (i) Energy shifts of new index */
+    int32_t *CritMax,   /* (i/o) Maximum Criteria (so far) */
+    int16_t *shTotMax,   /* (i/o) Shifts of maximum criteria */
+    size_t *bestIndex,   /* (i/o) Index that corresponds to
+                                                   maximum criteria */
+    int16_t *bestGain)   /* (i/o) Gain in Q14 that corresponds
+                                                   to maximum criteria */
+{
+  int16_t shOld, shNew, tmp16;
+  int16_t scaleTmp;
+  int32_t gainW32;
+
+  /* Normalize the new and old Criteria to the same domain */
+  if (CritNewSh>(*shTotMax)) {
+    shOld=WEBRTC_SPL_MIN(31,CritNewSh-(*shTotMax));
+    shNew=0;
+  } else {
+    shOld=0;
+    shNew=WEBRTC_SPL_MIN(31,(*shTotMax)-CritNewSh);
+  }
+
+  /* Compare the two criterias. If the new one is better,
+     calculate the gain and store this index as the new best one
+  */
+
+  if ((CritNew >> shNew) > (*CritMax >> shOld)) {
+
+    tmp16 = (int16_t)WebRtcSpl_NormW32(cDotNew);
+    tmp16 = 16 - tmp16;
+
+    /* Calculate the gain in Q14
+       Compensate for inverseEnergyshift in Q29 and that the energy
+       value was stored in a int16_t (shifted down 16 steps)
+       => 29-14+16 = 31 */
+
+    scaleTmp = -energyShiftNew-tmp16+31;
+    scaleTmp = WEBRTC_SPL_MIN(31, scaleTmp);
+
+    gainW32 = ((int16_t)WEBRTC_SPL_SHIFT_W32(cDotNew, -tmp16) * invEnergyNew) >>
+        scaleTmp;
+
+    /* Check if criteria satisfies Gain criteria (max 1.3)
+       if it is larger set the gain to 1.3
+       (slightly different from FLP version)
+    */
+    if (gainW32>21299) {
+      *bestGain=21299;
+    } else if (gainW32<-21299) {
+      *bestGain=-21299;
+    } else {
+      *bestGain=(int16_t)gainW32;
+    }
+
+    *CritMax=CritNew;
+    *shTotMax=CritNewSh;
+    *bestIndex = IndexNew;
+  }
+
+  return;
+}