| /* ------------------------------------------------------------------ |
| * 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/calc_en.c |
| Funtions: calc_unfilt_energies |
| calc_filt_energies |
| calc_target_energy |
| |
| ------------------------------------------------------------------------------ |
| MODULE DESCRIPTION |
| |
| This file contains the functions that calculate the energy coefficients |
| for unfiltered and filtered excitation signals, the LTP coding gain, and |
| the target energy. |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| |
| #include "calc_en.h" |
| #include "typedef.h" |
| #include "basicop_malloc.h" |
| #include "l_comp.h" |
| #include "cnst.h" |
| #include "log2.h" |
| #include "basic_op.h" |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL FUNCTION DEFINITIONS |
| ; Function Prototype declaration |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL VARIABLE DEFINITIONS |
| ; Variable declaration - defined here and used outside this module |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: calc_unfilt_energies |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| res = LP residual, buffer type Word16 |
| exc = LTP excitation (unfiltered), buffer type Word16 |
| code = CB innovation (unfiltered), buffer type Word16 |
| gain_pit = pitch gain, type Word16 |
| L_subfr = Subframe length, type Word16 |
| frac_en = energy coefficients (4), fraction part, buffer type Word16 |
| exp_en = energy coefficients (4), exponent part, buffer type Word16 |
| ltpg = LTP coding gain (log2()), pointer to type Word16 |
| pOverflow= pointer to value indicating existence of overflow (Flag) |
| |
| Outputs: |
| frac_en buffer containing new fractional parts of energy coefficients |
| exp_en buffer containing new exponential parts of energy coefficients |
| ltpg points to new LTP coding gain |
| pOverflow = 1 if there is an overflow else it is zero. |
| |
| Returns: |
| None. |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function calculates several energy coefficients for unfiltered |
| excitation signals and the LTP coding gain |
| |
| frac_en[0]*2^exp_en[0] = <res res> LP residual energy |
| frac_en[1]*2^exp_en[1] = <exc exc> LTP residual energy |
| frac_en[2]*2^exp_en[2] = <exc code> LTP/CB innovation dot product |
| frac_en[3]*2^exp_en[3] = <lres lres> LTP residual energy |
| (lres = res - gain_pit*exc) |
| ltpg = log2(LP_res_en / LTP_res_en) |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None. |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| calc_en.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| void |
| calc_unfilt_energies( |
| Word16 res[], // i : LP residual, Q0 |
| Word16 exc[], // i : LTP excitation (unfiltered), Q0 |
| Word16 code[], // i : CB innovation (unfiltered), Q13 |
| Word16 gain_pit, // i : pitch gain, Q14 |
| Word16 L_subfr, // i : Subframe length |
| |
| Word16 frac_en[], // o : energy coefficients (4), fraction part, Q15 |
| Word16 exp_en[], // o : energy coefficients (4), exponent part, Q0 |
| Word16 *ltpg // o : LTP coding gain (log2()), Q13 |
| ) |
| { |
| Word32 s, L_temp; |
| Word16 i, exp, tmp; |
| Word16 ltp_res_en, pred_gain; |
| Word16 ltpg_exp, ltpg_frac; |
| |
| // Compute residual energy |
| s = L_mac((Word32) 0, res[0], res[0]); |
| for (i = 1; i < L_subfr; i++) |
| s = L_mac(s, res[i], res[i]); |
| |
| // ResEn := 0 if ResEn < 200.0 (= 400 Q1) |
| if (L_sub (s, 400L) < 0) |
| { |
| frac_en[0] = 0; |
| exp_en[0] = -15; |
| } |
| else |
| { |
| exp = norm_l(s); |
| frac_en[0] = extract_h(L_shl(s, exp)); |
| exp_en[0] = sub(15, exp); |
| } |
| |
| // Compute ltp excitation energy |
| s = L_mac((Word32) 0, exc[0], exc[0]); |
| for (i = 1; i < L_subfr; i++) |
| s = L_mac(s, exc[i], exc[i]); |
| |
| exp = norm_l(s); |
| frac_en[1] = extract_h(L_shl(s, exp)); |
| exp_en[1] = sub(15, exp); |
| |
| // Compute scalar product <exc[],code[]> |
| s = L_mac((Word32) 0, exc[0], code[0]); |
| for (i = 1; i < L_subfr; i++) |
| s = L_mac(s, exc[i], code[i]); |
| |
| exp = norm_l(s); |
| frac_en[2] = extract_h(L_shl(s, exp)); |
| exp_en[2] = sub(16-14, exp); |
| |
| // Compute energy of LTP residual |
| s = 0L; |
| for (i = 0; i < L_subfr; i++) |
| { |
| L_temp = L_mult(exc[i], gain_pit); |
| L_temp = L_shl(L_temp, 1); |
| tmp = sub(res[i], pv_round(L_temp)); // LTP residual, Q0 |
| s = L_mac (s, tmp, tmp); |
| } |
| |
| exp = norm_l(s); |
| ltp_res_en = extract_h (L_shl (s, exp)); |
| exp = sub (15, exp); |
| |
| frac_en[3] = ltp_res_en; |
| exp_en[3] = exp; |
| |
| // calculate LTP coding gain, i.e. energy reduction LP res -> LTP res |
| if (ltp_res_en > 0 && frac_en[0] != 0) |
| { |
| // gain = ResEn / LTPResEn |
| pred_gain = div_s (shr (frac_en[0], 1), ltp_res_en); |
| exp = sub (exp, exp_en[0]); |
| |
| // L_temp = ltpGain * 2^(30 + exp) |
| L_temp = L_deposit_h (pred_gain); |
| // L_temp = ltpGain * 2^27 |
| L_temp = L_shr (L_temp, add (exp, 3)); |
| |
| // Log2 = log2() + 27 |
| Log2(L_temp, <pg_exp, <pg_frac); |
| |
| // ltpg = log2(LtpGain) * 2^13 --> range: +- 4 = +- 12 dB |
| L_temp = L_Comp (sub (ltpg_exp, 27), ltpg_frac); |
| *ltpg = pv_round (L_shl (L_temp, 13)); // Q13 |
| } |
| else |
| { |
| *ltpg = 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] |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| void calc_unfilt_energies( |
| Word16 res[], /* i : LP residual, Q0 */ |
| Word16 exc[], /* i : LTP excitation (unfiltered), Q0 */ |
| Word16 code[], /* i : CB innovation (unfiltered), Q13 */ |
| Word16 gain_pit, /* i : pitch gain, Q14 */ |
| Word16 L_subfr, /* i : Subframe length */ |
| |
| Word16 frac_en[], /* o : energy coefficients (4), fraction part, Q15 */ |
| Word16 exp_en[], /* o : energy coefficients (4), exponent part, Q0 */ |
| Word16 *ltpg, /* o : LTP coding gain (log2()), Q13 */ |
| Flag *pOverflow |
| ) |
| { |
| Word32 s1; /* Intermediate energy accumulator */ |
| Word32 s2; /* Intermediate energy accumulator */ |
| Word32 s3; /* Intermediate energy accumulator */ |
| Word32 s4; /* Intermediate energy accumulator */ |
| Word32 L_temp; /* temporal 32 bits storage */ |
| |
| Word16 i; /* index used in all loops */ |
| Word16 exp; /* nunmber of '0's or '1's before MSB != 0 */ |
| Word16 tmp1; /* temporal storage */ |
| Word16 tmp2; /* temporal storage */ |
| Word16 ltp_res_en; |
| Word16 pred_gain; /* predictor gain */ |
| Word16 ltpg_exp; /* LTP gain (exponent) */ |
| Word16 ltpg_frac; /* LTP gain (mantissa or fractional part) */ |
| |
| s1 = 0; |
| s2 = 0; |
| s3 = 0; |
| s4 = 0; |
| |
| /*---------------------------------------------------------------------------- |
| NOTE: Overflow is expected as a result of multiply and accumulated without |
| scale down the inputs. This modification is not made at this point |
| to have bit exact results with the pre-optimization code. (JT 6/20/00) |
| |
| ----------------------------------------------------------------------------*/ |
| |
| for (i = 0; i < L_subfr; i++) |
| { |
| tmp1 = res[i]; /* avoid multiple accesses to memory */ |
| tmp2 = exc[i]; |
| |
| s1 = amrnb_fxp_mac_16_by_16bb((Word32) tmp1, (Word32) tmp1, s1); /* Compute residual energy */ |
| s2 = amrnb_fxp_mac_16_by_16bb((Word32) tmp2, (Word32) tmp2, s2); /* Compute ltp excitation energy */ |
| s3 = amrnb_fxp_mac_16_by_16bb((Word32) tmp2, (Word32) code[i], s3);/* Compute scalar product */ |
| /* <exc[],code[]> */ |
| |
| L_temp = L_mult(tmp2, gain_pit, pOverflow); |
| L_temp = L_shl(L_temp, 1, pOverflow); |
| tmp2 = sub(tmp1, pv_round(L_temp, pOverflow), pOverflow); |
| /* LTP residual, Q0 */ |
| s4 = L_mac(s4, tmp2, tmp2, pOverflow); |
| /* Compute energy of LTP residual */ |
| } |
| s1 = s1 << 1; |
| s2 = s2 << 1; |
| s3 = s3 << 1; |
| |
| if (s1 & MIN_32) |
| { |
| s1 = MAX_32; |
| *pOverflow = 1; |
| } |
| |
| /* ResEn := 0 if ResEn < 200.0 (= 400 Q1) */ |
| if (s1 < 400L) |
| { |
| frac_en[0] = 0; |
| exp_en[0] = -15; |
| } |
| else |
| { |
| exp = norm_l(s1); |
| frac_en[0] = (Word16)(L_shl(s1, exp, pOverflow) >> 16); |
| exp_en[0] = (15 - exp); |
| } |
| |
| if (s2 & MIN_32) |
| { |
| s2 = MAX_32; |
| *pOverflow = 1; |
| } |
| |
| exp = norm_l(s2); |
| frac_en[1] = (Word16)(L_shl(s2, exp, pOverflow) >> 16); |
| exp_en[1] = sub(15, exp, pOverflow); |
| |
| /* s3 is not always sum of squares */ |
| exp = norm_l(s3); |
| frac_en[2] = (Word16)(L_shl(s3, exp, pOverflow) >> 16); |
| exp_en[2] = 2 - exp; |
| |
| exp = norm_l(s4); |
| ltp_res_en = (Word16)(L_shl(s4, exp, pOverflow) >> 16); |
| exp = sub(15, exp, pOverflow); |
| |
| frac_en[3] = ltp_res_en; |
| exp_en[3] = exp; |
| |
| /* calculate LTP coding gain, i.e. energy reduction LP res -> LTP res */ |
| |
| if (ltp_res_en > 0 && frac_en[0] != 0) |
| { |
| /* gain = ResEn / LTPResEn */ |
| pred_gain = div_s(shr(frac_en[0], 1, pOverflow), ltp_res_en); |
| exp = sub(exp, exp_en[0], pOverflow); |
| |
| /* L_temp = ltpGain * 2^(30 + exp) */ |
| L_temp = (Word32) pred_gain << 16; |
| /* L_temp = ltpGain * 2^27 */ |
| L_temp = L_shr(L_temp, (Word16)(exp + 3), pOverflow); |
| |
| /* Log2 = log2() + 27 */ |
| Log2(L_temp, <pg_exp, <pg_frac, pOverflow); |
| |
| /* ltpg = log2(LtpGain) * 2^13 --> range: +- 4 = +- 12 dB */ |
| L_temp = L_Comp(sub(ltpg_exp, 27, pOverflow), ltpg_frac, pOverflow); |
| *ltpg = pv_round(L_shl(L_temp, 13, pOverflow), pOverflow); /* Q13 */ |
| } |
| else |
| { |
| *ltpg = 0; |
| } |
| |
| return; |
| } |
| |
| /****************************************************************************/ |
| |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: calc_filt_energies |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| mode = coder mode, type Mode |
| xn = LTP target vector, buffer type Word16 |
| xn2 = CB target vector, buffer type Word16 |
| y1 = Adaptive codebook, buffer type Word16 |
| Y2 = Filtered innovative vector, buffer type Word16 |
| g_coeff = Correlations <xn y1> <y1 y1> |
| computed in G_pitch() buffer type Word16 |
| frac_coeff = energy coefficients (5), fraction part, buffer type Word16 |
| exp_coeff = energy coefficients (5), exponent part, buffer type Word16 |
| cod_gain_frac = optimum codebook gain (fraction part), pointer type Word16 |
| cod_gain_exp = optimum codebook gain (exponent part), pointer type Word16 |
| pOverflow = pointer to overflow indicator (Flag) |
| |
| Outputs: |
| frac_coeff contains new fraction part energy coefficients |
| exp_coeff contains new exponent part energy coefficients |
| cod_gain_frac points to the new optimum codebook gain (fraction part) |
| cod_gain_exp points to the new optimum codebook gain (exponent part) |
| pOverflow = 1 if there is an overflow else it is zero. |
| |
| Returns: |
| None. |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function calculates several energy coefficients for filtered |
| excitation signals |
| |
| Compute coefficients need for the quantization and the optimum |
| codebook gain gcu (for MR475 only). |
| |
| coeff[0] = y1 y1 |
| coeff[1] = -2 xn y1 |
| coeff[2] = y2 y2 |
| coeff[3] = -2 xn y2 |
| coeff[4] = 2 y1 y2 |
| |
| gcu = <xn2, y2> / <y2, y2> (0 if <xn2, y2> <= 0) |
| |
| Product <y1 y1> and <xn y1> have been computed in G_pitch() and |
| are in vector g_coeff[]. |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None. |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| calc_en.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| void |
| calc_filt_energies( |
| enum Mode mode, // i : coder mode |
| Word16 xn[], // i : LTP target vector, Q0 |
| Word16 xn2[], // i : CB target vector, Q0 |
| Word16 y1[], // i : Adaptive codebook, Q0 |
| Word16 Y2[], // i : Filtered innovative vector, Q12 |
| Word16 g_coeff[], // i : Correlations <xn y1> <y1 y1> |
| // computed in G_pitch() |
| |
| Word16 frac_coeff[],// o : energy coefficients (5), fraction part, Q15 |
| Word16 exp_coeff[], // o : energy coefficients (5), exponent part, Q0 |
| Word16 *cod_gain_frac,// o: optimum codebook gain (fraction part), Q15 |
| Word16 *cod_gain_exp // o: optimum codebook gain (exponent part), Q0 |
| ) |
| { |
| Word32 s, ener_init; |
| Word16 i, exp, frac; |
| Word16 y2[L_SUBFR]; |
| |
| if (sub(mode, MR795) == 0 || sub(mode, MR475) == 0) |
| { |
| ener_init = 0L; |
| } |
| else |
| { |
| ener_init = 1L; |
| } |
| |
| for (i = 0; i < L_SUBFR; i++) { |
| y2[i] = shr(Y2[i], 3); |
| } |
| |
| frac_coeff[0] = g_coeff[0]; |
| exp_coeff[0] = g_coeff[1]; |
| frac_coeff[1] = negate(g_coeff[2]); // coeff[1] = -2 xn y1 |
| exp_coeff[1] = add(g_coeff[3], 1); |
| |
| |
| // Compute scalar product <y2[],y2[]> |
| |
| s = L_mac(ener_init, y2[0], y2[0]); |
| for (i = 1; i < L_SUBFR; i++) |
| s = L_mac(s, y2[i], y2[i]); |
| |
| exp = norm_l(s); |
| frac_coeff[2] = extract_h(L_shl(s, exp)); |
| exp_coeff[2] = sub(15 - 18, exp); |
| |
| // Compute scalar product -2*<xn[],y2[]> |
| |
| s = L_mac(ener_init, xn[0], y2[0]); |
| for (i = 1; i < L_SUBFR; i++) |
| s = L_mac(s, xn[i], y2[i]); |
| |
| exp = norm_l(s); |
| frac_coeff[3] = negate(extract_h(L_shl(s, exp))); |
| exp_coeff[3] = sub(15 - 9 + 1, exp); |
| |
| |
| // Compute scalar product 2*<y1[],y2[]> |
| |
| s = L_mac(ener_init, y1[0], y2[0]); |
| for (i = 1; i < L_SUBFR; i++) |
| s = L_mac(s, y1[i], y2[i]); |
| |
| exp = norm_l(s); |
| frac_coeff[4] = extract_h(L_shl(s, exp)); |
| exp_coeff[4] = sub(15 - 9 + 1, exp); |
| |
| if (sub(mode, MR475) == 0 || sub(mode, MR795) == 0) |
| { |
| // Compute scalar product <xn2[],y2[]> |
| |
| s = L_mac(ener_init, xn2[0], y2[0]); |
| for (i = 1; i < L_SUBFR; i++) |
| s = L_mac(s, xn2[i], y2[i]); |
| |
| exp = norm_l(s); |
| frac = extract_h(L_shl(s, exp)); |
| exp = sub(15 - 9, exp); |
| |
| |
| if (frac <= 0) |
| { |
| *cod_gain_frac = 0; |
| *cod_gain_exp = 0; |
| } |
| else |
| { |
| // |
| gcu = <xn2, y2> / c[2] |
| = (frac>>1)/frac[2] * 2^(exp+1-exp[2]) |
| = div_s(frac>>1, frac[2])*2^-15 * 2^(exp+1-exp[2]) |
| = div_s * 2^(exp-exp[2]-14) |
| |
| *cod_gain_frac = div_s (shr (frac,1), frac_coeff[2]); |
| *cod_gain_exp = sub (sub (exp, exp_coeff[2]), 14); |
| |
| } |
| } |
| } |
| |
| ------------------------------------------------------------------------------ |
| 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] |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| void calc_filt_energies( |
| enum Mode mode, /* i : coder mode */ |
| Word16 xn[], /* i : LTP target vector, Q0 */ |
| Word16 xn2[], /* i : CB target vector, Q0 */ |
| Word16 y1[], /* i : Adaptive codebook, Q0 */ |
| Word16 Y2[], /* i : Filtered innovative vector, Q12 */ |
| Word16 g_coeff[], /* i : Correlations <xn y1> <y1 y1> */ |
| /* computed in G_pitch() */ |
| Word16 frac_coeff[], /* o : energy coefficients (5), fraction part, Q15 */ |
| Word16 exp_coeff[], /* o : energy coefficients (5), exponent part, Q0 */ |
| Word16 *cod_gain_frac, /* o : optimum codebook gain (fraction part),Q15 */ |
| Word16 *cod_gain_exp, /* o : optimum codebook gain (exponent part), Q0 */ |
| Flag *pOverflow |
| ) |
| { |
| Word32 s1; /* Intermediate energy accumulator */ |
| Word32 s2; /* Intermediate energy accumulator */ |
| Word32 s3; /* Intermediate energy accumulator */ |
| |
| Word16 i; /* index used in all loops */ |
| Word16 exp; /* number of '0's or '1's before MSB != 0 */ |
| Word16 frac; /* fractional part */ |
| Word16 tmp; /* temporal storage */ |
| Word16 scaled_y2[L_SUBFR]; |
| |
| |
| frac_coeff[0] = g_coeff[0]; |
| exp_coeff[0] = g_coeff[1]; |
| frac_coeff[1] = negate(g_coeff[2]); /* coeff[1] = -2 xn y1 */ |
| exp_coeff[1] = add(g_coeff[3], 1, pOverflow); |
| |
| if ((mode == MR795) || (mode == MR475)) |
| { |
| s1 = 0L; |
| s2 = 0L; |
| s3 = 0L; |
| } |
| else |
| { |
| s1 = 1L; |
| s2 = 1L; |
| s3 = 1L; |
| } |
| |
| for (i = 0; i < L_SUBFR; i++) |
| { |
| /* avoid multiple accesses to memory */ |
| tmp = (Y2[i] >> 3); |
| scaled_y2[i] = tmp; |
| |
| /* Compute scalar product <scaled_y2[],scaled_y2[]> */ |
| s1 = L_mac(s1, tmp, tmp, pOverflow); |
| |
| /* Compute scalar product -2*<xn[],scaled_y2[]> */ |
| s2 = L_mac(s2, xn[i], tmp, pOverflow); |
| |
| /* Compute scalar product 2*<y1[],scaled_y2[]> */ |
| s3 = L_mac(s3, y1[i], tmp, pOverflow); |
| } |
| |
| exp = norm_l(s1); |
| frac_coeff[2] = (Word16)(L_shl(s1, exp, pOverflow) >> 16); |
| exp_coeff[2] = (-3 - exp); |
| |
| exp = norm_l(s2); |
| frac_coeff[3] = negate((Word16)(L_shl(s2, exp, pOverflow) >> 16)); |
| exp_coeff[3] = (7 - exp); |
| |
| exp = norm_l(s3); |
| frac_coeff[4] = (Word16)(L_shl(s3, exp, pOverflow) >> 16); |
| exp_coeff[4] = sub(7, exp, pOverflow); |
| |
| |
| if ((mode == MR795) || (mode == MR475)) |
| { |
| /* Compute scalar product <xn2[],scaled_y2[]> */ |
| s1 = 0L; |
| |
| for (i = 0; i < L_SUBFR; i++) |
| { |
| s1 = amrnb_fxp_mac_16_by_16bb((Word32) xn2[i], (Word32)scaled_y2[i], s1); |
| } |
| |
| s1 = s1 << 1; |
| |
| exp = norm_l(s1); |
| frac = (Word16)(L_shl(s1, exp, pOverflow) >> 16); |
| exp = (6 - exp); |
| |
| if (frac <= 0) |
| { |
| *cod_gain_frac = 0; |
| *cod_gain_exp = 0; |
| } |
| else |
| { |
| /* |
| gcu = <xn2, scaled_y2> / c[2] |
| = (frac>>1)/frac[2] * 2^(exp+1-exp[2]) |
| = div_s(frac>>1, frac[2])*2^-15 * 2^(exp+1-exp[2]) |
| = div_s * 2^(exp-exp[2]-14) |
| */ |
| *cod_gain_frac = div_s(shr(frac, 1, pOverflow), frac_coeff[2]); |
| *cod_gain_exp = ((exp - exp_coeff[2]) - 14); |
| } |
| } |
| |
| return; |
| } |
| |
| /****************************************************************************/ |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: calc_target_energy |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| xn = LTP target vector, buffer to type Word16 Q0 |
| en_exp = optimum codebook gain (exponent part) pointer to type Word16 |
| en_frac = optimum codebook gain (fraction part) pointer to type Word16 |
| pOverflow = pointer to overflow indicator (Flag) |
| |
| Outputs: |
| en_exp points to new optimum codebook gain (exponent part) |
| en_frac points to new optimum codebook gain (fraction part) |
| pOverflow = 1 if there is an overflow else it is zero. |
| |
| Returns: |
| None. |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function calculates the target energy using the formula, |
| en = <xn, xn> |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None. |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| calc_en.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| void |
| calc_target_energy( |
| Word16 xn[], // i: LTP target vector, Q0 |
| Word16 *en_exp, // o: optimum codebook gain (exponent part), Q0 |
| Word16 *en_frac // o: optimum codebook gain (fraction part), Q15 |
| ) |
| { |
| Word32 s; |
| Word16 i, exp; |
| |
| // Compute scalar product <xn[], xn[]> |
| s = L_mac(0L, xn[0], xn[0]); |
| for (i = 1; i < L_SUBFR; i++) |
| s = L_mac(s, xn[i], xn[i]); |
| |
| // s = SUM 2*xn(i) * xn(i) = <xn xn> * 2 |
| exp = norm_l(s); |
| *en_frac = extract_h(L_shl(s, exp)); |
| *en_exp = sub(16, exp); |
| } |
| |
| ------------------------------------------------------------------------------ |
| 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] |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| void calc_target_energy( |
| Word16 xn[], /* i: LTP target vector, Q0 */ |
| Word16 *en_exp, /* o: optimum codebook gain (exponent part), Q0 */ |
| Word16 *en_frac, /* o: optimum codebook gain (fraction part), Q15 */ |
| Flag *pOverflow |
| ) |
| { |
| Word32 s; /* Intermediate energy accumulator */ |
| Word16 i; /* index used in all loops */ |
| Word16 exp; |
| |
| /* Compute scalar product <xn[], xn[]> */ |
| s = 0; |
| for (i = 0; i < L_SUBFR; i++) |
| { |
| s = amrnb_fxp_mac_16_by_16bb((Word32) xn[i], (Word32) xn[i], s); |
| } |
| |
| if (s < 0) |
| { |
| *pOverflow = 1; |
| s = MAX_32; |
| } |
| |
| /* s = SUM 2*xn(i) * xn(i) = <xn xn> * 2 */ |
| exp = norm_l(s); |
| *en_frac = (Word16)(L_shl(s, exp, pOverflow) >> 16); |
| *en_exp = (16 - exp); |
| |
| return; |
| } |
| |
| |
