| /* ------------------------------------------------------------------ |
| * Copyright (C) 1998-2009 PacketVideo |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either |
| * express or implied. |
| * See the License for the specific language governing permissions |
| * and limitations under the License. |
| * ------------------------------------------------------------------- |
| */ |
| /**************************************************************************************** |
| Portions of this file are derived from the following 3GPP standard: |
| |
| 3GPP TS 26.073 |
| ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec |
| Available from http://www.3gpp.org |
| |
| (C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) |
| Permission to distribute, modify and use this file under the standard license |
| terms listed above has been obtained from the copyright holder. |
| ****************************************************************************************/ |
| /* |
| ------------------------------------------------------------------------------ |
| |
| Pathname: ./audio/gsm-amr/c/src/bgnscd.c |
| Functions: |
| Bgn_scd_reset |
| Bgn_scd |
| |
| ------------------------------------------------------------------------------ |
| MODULE DESCRIPTION |
| |
| Background noise source characteristic detector (SCD) |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include <string.h> |
| |
| #include "bgnscd.h" |
| #include "typedef.h" |
| #include "basic_op.h" |
| #include "cnst.h" |
| #include "copy.h" |
| #include "gmed_n.h" |
| #include "sqrt_l.h" |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| #define TRUE 1 |
| #define FALSE 0 |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL FUNCTION DEFINITIONS |
| ; Function Prototype declaration |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL VARIABLE DEFINITIONS |
| ; Variable declaration - defined here and used outside this module |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: Bgn_scd_reset |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| state = points to memory of type Bgn_scdState. |
| |
| Outputs: |
| The memory of type Bgn_scdState pointed to by state is set to all |
| zeros. |
| |
| Returns: |
| Returns 0 if memory was successfully initialized, |
| otherwise returns -1. |
| |
| Global Variables Used: |
| None. |
| |
| Local Variables Needed: |
| None. |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| Resets state memory. |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| bgnscd.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| Word16 Bgn_scd_reset (Bgn_scdState *state) |
| { |
| if (state == (Bgn_scdState *) NULL){ |
| fprintf(stderr, "Bgn_scd_reset: invalid parameter\n"); |
| return -1; |
| } |
| |
| // Static vectors to zero |
| Set_zero (state->frameEnergyHist, L_ENERGYHIST); |
| |
| // Initialize hangover handling |
| state->bgHangover = 0; |
| |
| return 0; |
| } |
| |
| ------------------------------------------------------------------------------ |
| RESOURCES USED [optional] |
| |
| When the code is written for a specific target processor the |
| the resources used should be documented below. |
| |
| HEAP MEMORY USED: x bytes |
| |
| STACK MEMORY USED: x bytes |
| |
| CLOCK CYCLES: (cycle count equation for this function) + (variable |
| used to represent cycle count for each subroutine |
| called) |
| where: (cycle count variable) = cycle count for [subroutine |
| name] |
| |
| ------------------------------------------------------------------------------ |
| CAUTION [optional] |
| [State any special notes, constraints or cautions for users of this function] |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| Word16 Bgn_scd_reset(Bgn_scdState *state) |
| { |
| if (state == (Bgn_scdState *) NULL) |
| { |
| /* fprintf(stderr, "Bgn_scd_reset: invalid parameter\n"); */ |
| return(-1); |
| } |
| |
| /* Static vectors to zero */ |
| memset(state->frameEnergyHist, 0, L_ENERGYHIST*sizeof(Word16)); |
| |
| /* Initialize hangover handling */ |
| state->bgHangover = 0; |
| |
| return(0); |
| } |
| |
| /****************************************************************************/ |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: Bgn_scd |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| st = pointer to state variables of type Bgn_scdState |
| ltpGainHist[] = LTP gain history (Word16) |
| speech[] = synthesis speech frame (Word16) |
| voicedHangover = pointer to # of frames after last voiced frame (Word16) |
| pOverflow = pointer to overflow indicator (Flag) |
| |
| Outputs: |
| st = function updates the state variables of type Bgn_scdState |
| pointed to by st. |
| voicedHangover = function updates the # of frames after last voiced |
| frame pointed to by voicedHangover. |
| pOverflow = 1 if the basic math function L_add() results in saturation. |
| else pOverflow is zero. |
| |
| Returns: |
| inbgNoise = flag if background noise is present (Word16) |
| |
| Global Variables Used: |
| None. |
| |
| Local Variables Needed: |
| None. |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| Characterize synthesis speech and detect background noise. |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| bgnscd.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| Word16 Bgn_scd (Bgn_scdState *st, // i : State variables for bgn SCD |
| Word16 ltpGainHist[], // i : LTP gain history |
| Word16 speech[], // o : synthesis speech frame |
| Word16 *voicedHangover // o : # of frames after last |
| voiced frame |
| ) |
| { |
| Word16 i; |
| Word16 prevVoiced, inbgNoise; |
| Word16 temp; |
| Word16 ltpLimit, frameEnergyMin; |
| Word16 currEnergy, noiseFloor, maxEnergy, maxEnergyLastPart; |
| Word32 s; |
| |
| // Update the inBackgroundNoise flag (valid for use in next frame if BFI) |
| // it now works as a energy detector floating on top |
| // not as good as a VAD. |
| |
| currEnergy = 0; |
| s = (Word32) 0; |
| |
| for (i = 0; i < L_FRAME; i++) |
| { |
| s = L_mac (s, speech[i], speech[i]); |
| } |
| |
| s = L_shl(s, 2); |
| |
| currEnergy = extract_h (s); |
| |
| frameEnergyMin = 32767; |
| |
| for (i = 0; i < L_ENERGYHIST; i++) |
| { |
| if (sub(st->frameEnergyHist[i], frameEnergyMin) < 0) |
| frameEnergyMin = st->frameEnergyHist[i]; |
| } |
| |
| noiseFloor = shl (frameEnergyMin, 4); // Frame Energy Margin of 16 |
| |
| maxEnergy = st->frameEnergyHist[0]; |
| for (i = 1; i < L_ENERGYHIST-4; i++) |
| { |
| if ( sub (maxEnergy, st->frameEnergyHist[i]) < 0) |
| { |
| maxEnergy = st->frameEnergyHist[i]; |
| } |
| } |
| |
| maxEnergyLastPart = st->frameEnergyHist[2*L_ENERGYHIST/3]; |
| for (i = 2*L_ENERGYHIST/3+1; i < L_ENERGYHIST; i++) |
| { |
| if ( sub (maxEnergyLastPart, st->frameEnergyHist[i] ) < 0) |
| { |
| maxEnergyLastPart = st->frameEnergyHist[i]; |
| } |
| } |
| |
| inbgNoise = 0; // false |
| |
| // Do not consider silence as noise |
| // Do not consider continuous high volume as noise |
| // Or if the current noise level is very low |
| // Mark as noise if under current noise limit |
| // OR if the maximum energy is below the upper limit |
| |
| if ( (sub(maxEnergy, LOWERNOISELIMIT) > 0) && |
| (sub(currEnergy, FRAMEENERGYLIMIT) < 0) && |
| (sub(currEnergy, LOWERNOISELIMIT) > 0) && |
| ( (sub(currEnergy, noiseFloor) < 0) || |
| (sub(maxEnergyLastPart, UPPERNOISELIMIT) < 0))) |
| { |
| if (sub(add(st->bgHangover, 1), 30) > 0) |
| { |
| st->bgHangover = 30; |
| } else |
| { |
| st->bgHangover = add(st->bgHangover, 1); |
| } |
| } |
| else |
| { |
| st->bgHangover = 0; |
| } |
| |
| // make final decision about frame state , act somewhat cautiosly |
| if (sub(st->bgHangover,1) > 0) |
| inbgNoise = 1; // true |
| |
| for (i = 0; i < L_ENERGYHIST-1; i++) |
| { |
| st->frameEnergyHist[i] = st->frameEnergyHist[i+1]; |
| } |
| st->frameEnergyHist[L_ENERGYHIST-1] = currEnergy; |
| |
| // prepare for voicing decision; tighten the threshold after some |
| time in noise |
| ltpLimit = 13926; // 0.85 Q14 |
| if (sub(st->bgHangover, 8) > 0) |
| { |
| ltpLimit = 15565; // 0.95 Q14 |
| } |
| if (sub(st->bgHangover, 15) > 0) |
| { |
| ltpLimit = 16383; // 1.00 Q14 |
| } |
| |
| // weak sort of voicing indication. |
| prevVoiced = 0; // false |
| |
| if (sub(gmed_n(<pGainHist[4], 5), ltpLimit) > 0) |
| { |
| prevVoiced = 1; // true |
| } |
| if (sub(st->bgHangover, 20) > 0) { |
| if (sub(gmed_n(ltpGainHist, 9), ltpLimit) > 0) |
| { |
| prevVoiced = 1; // true |
| } |
| else |
| { |
| prevVoiced = 0; // false |
| } |
| } |
| |
| if (prevVoiced) |
| { |
| *voicedHangover = 0; |
| } |
| else |
| { |
| temp = add(*voicedHangover, 1); |
| if (sub(temp, 10) > 0) |
| { |
| *voicedHangover = 10; |
| } |
| else |
| { |
| *voicedHangover = temp; |
| } |
| } |
| |
| return inbgNoise; |
| } |
| |
| ------------------------------------------------------------------------------ |
| RESOURCES USED [optional] |
| |
| When the code is written for a specific target processor the |
| the resources used should be documented below. |
| |
| HEAP MEMORY USED: x bytes |
| |
| STACK MEMORY USED: x bytes |
| |
| CLOCK CYCLES: (cycle count equation for this function) + (variable |
| used to represent cycle count for each subroutine |
| called) |
| where: (cycle count variable) = cycle count for [subroutine |
| name] |
| |
| ------------------------------------------------------------------------------ |
| CAUTION [optional] |
| [State any special notes, constraints or cautions for users of this function] |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| Word16 Bgn_scd(Bgn_scdState *st, /* i : State variables for bgn SCD */ |
| Word16 ltpGainHist[], /* i : LTP gain history */ |
| Word16 speech[], /* o : synthesis speech frame */ |
| Word16 *voicedHangover,/* o : # of frames after last |
| voiced frame */ |
| Flag *pOverflow |
| ) |
| { |
| Word16 i; |
| Word16 prevVoiced, inbgNoise; |
| Word16 temp; |
| Word16 ltpLimit, frameEnergyMin; |
| Word16 currEnergy, noiseFloor, maxEnergy, maxEnergyLastPart; |
| Word32 s, L_temp; |
| |
| |
| /* Update the inBackgroundNoise flag (valid for use in next frame if BFI) */ |
| /* it now works as a energy detector floating on top */ |
| /* not as good as a VAD. */ |
| |
| s = (Word32) 0; |
| |
| for (i = L_FRAME - 1; i >= 0; i--) |
| { |
| L_temp = ((Word32) speech[i]) * speech[i]; |
| if (L_temp != (Word32) 0x40000000L) |
| { |
| L_temp = L_temp << 1; |
| } |
| else |
| { |
| L_temp = MAX_32; |
| } |
| s = L_add(s, L_temp, pOverflow); |
| } |
| |
| /* s is a sum of squares, so don't need to check for neg overflow */ |
| if (s > (Word32)0x1fffffffL) |
| { |
| currEnergy = MAX_16; |
| } |
| else |
| { |
| currEnergy = (Word16)(s >> 14); |
| } |
| |
| frameEnergyMin = 32767; |
| for (i = L_ENERGYHIST - 1; i >= 0; i--) |
| { |
| if (st->frameEnergyHist[i] < frameEnergyMin) |
| { |
| frameEnergyMin = st->frameEnergyHist[i]; |
| } |
| } |
| |
| /* Frame Energy Margin of 16 */ |
| L_temp = (Word32)frameEnergyMin << 4; |
| if (L_temp != (Word32)((Word16) L_temp)) |
| { |
| if (L_temp > 0) |
| { |
| noiseFloor = MAX_16; |
| } |
| else |
| { |
| noiseFloor = MIN_16; |
| } |
| } |
| else |
| { |
| noiseFloor = (Word16)(L_temp); |
| } |
| |
| maxEnergy = st->frameEnergyHist[0]; |
| for (i = L_ENERGYHIST - 5; i >= 1; i--) |
| { |
| if (maxEnergy < st->frameEnergyHist[i]) |
| { |
| maxEnergy = st->frameEnergyHist[i]; |
| } |
| } |
| |
| maxEnergyLastPart = st->frameEnergyHist[2*L_ENERGYHIST/3]; |
| for (i = 2 * L_ENERGYHIST / 3 + 1; i < L_ENERGYHIST; i++) |
| { |
| if (maxEnergyLastPart < st->frameEnergyHist[i]) |
| { |
| maxEnergyLastPart = st->frameEnergyHist[i]; |
| } |
| } |
| |
| /* Do not consider silence as noise */ |
| /* Do not consider continuous high volume as noise */ |
| /* Or if the current noise level is very low */ |
| /* Mark as noise if under current noise limit */ |
| /* OR if the maximum energy is below the upper limit */ |
| |
| if ((maxEnergy > LOWERNOISELIMIT) && |
| (currEnergy < FRAMEENERGYLIMIT) && |
| (currEnergy > LOWERNOISELIMIT) && |
| ((currEnergy < noiseFloor) || |
| (maxEnergyLastPart < UPPERNOISELIMIT))) |
| { |
| if ((st->bgHangover + 1) > 30) |
| { |
| st->bgHangover = 30; |
| } |
| else |
| { |
| st->bgHangover += 1; |
| } |
| } |
| else |
| { |
| st->bgHangover = 0; |
| } |
| |
| /* make final decision about frame state , act somewhat cautiosly */ |
| |
| if (st->bgHangover > 1) |
| { |
| inbgNoise = TRUE; |
| } |
| else |
| { |
| inbgNoise = FALSE; |
| } |
| |
| for (i = 0; i < L_ENERGYHIST - 1; i++) |
| { |
| st->frameEnergyHist[i] = st->frameEnergyHist[i+1]; |
| } |
| st->frameEnergyHist[L_ENERGYHIST-1] = currEnergy; |
| |
| /* prepare for voicing decision; tighten the threshold after some |
| time in noise */ |
| |
| if (st->bgHangover > 15) |
| { |
| ltpLimit = 16383; /* 1.00 Q14 */ |
| } |
| else if (st->bgHangover > 8) |
| { |
| ltpLimit = 15565; /* 0.95 Q14 */ |
| } |
| else |
| { |
| ltpLimit = 13926; /* 0.85 Q14 */ |
| } |
| |
| /* weak sort of voicing indication. */ |
| prevVoiced = FALSE; |
| |
| if (gmed_n(<pGainHist[4], 5) > ltpLimit) |
| { |
| prevVoiced = TRUE; |
| } |
| |
| if (st->bgHangover > 20) |
| { |
| if (gmed_n(ltpGainHist, 9) > ltpLimit) |
| { |
| prevVoiced = TRUE; |
| } |
| else |
| { |
| prevVoiced = FALSE; |
| } |
| } |
| |
| |
| if (prevVoiced) |
| { |
| *voicedHangover = 0; |
| } |
| else |
| { |
| temp = *voicedHangover + 1; |
| |
| if (temp > 10) |
| { |
| *voicedHangover = 10; |
| } |
| else |
| { |
| *voicedHangover = temp; |
| } |
| } |
| |
| return(inbgNoise); |
| } |
