blob: bf85408590dc68487899114f2cbb26a558bd170c [file] [log] [blame]
* 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
#include "defines.h"
#include "cb_update_best_index.h"
#include "constants.h"
void WebRtcIlbcfix_CbUpdateBestIndex(
WebRtc_Word32 CritNew, /* (i) New Potentially best Criteria */
WebRtc_Word16 CritNewSh, /* (i) Shift value of above Criteria */
WebRtc_Word16 IndexNew, /* (i) Index of new Criteria */
WebRtc_Word32 cDotNew, /* (i) Cross dot of new index */
WebRtc_Word16 invEnergyNew, /* (i) Inversed energy new index */
WebRtc_Word16 energyShiftNew, /* (i) Energy shifts of new index */
WebRtc_Word32 *CritMax, /* (i/o) Maximum Criteria (so far) */
WebRtc_Word16 *shTotMax, /* (i/o) Shifts of maximum criteria */
WebRtc_Word16 *bestIndex, /* (i/o) Index that corresponds to
maximum criteria */
WebRtc_Word16 *bestGain) /* (i/o) Gain in Q14 that corresponds
to maximum criteria */
WebRtc_Word16 shOld, shNew, tmp16;
WebRtc_Word16 scaleTmp;
WebRtc_Word32 gainW32;
/* Normalize the new and old Criteria to the same domain */
if (CritNewSh>(*shTotMax)) {
} else {
/* Compare the two criterias. If the new one is better,
calculate the gain and store this index as the new best one
if (WEBRTC_SPL_RSHIFT_W32(CritNew, shNew)>
WEBRTC_SPL_RSHIFT_W32((*CritMax),shOld)) {
tmp16 = (WebRtc_Word16)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 WebRtc_Word16 (shifted down 16 steps)
=> 29-14+16 = 31 */
scaleTmp = -energyShiftNew-tmp16+31;
scaleTmp = WEBRTC_SPL_MIN(31, scaleTmp);
gainW32 = WEBRTC_SPL_MUL_16_16_RSFT(
((WebRtc_Word16)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) {
} else if (gainW32<-21299) {
} else {
*bestIndex = IndexNew;