diff options
Diffstat (limited to 'third_party/libwebrtc/modules/audio_coding/codecs/ilbc/cb_update_best_index.c')
-rw-r--r-- | third_party/libwebrtc/modules/audio_coding/codecs/ilbc/cb_update_best_index.c | 89 |
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; +} |