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+/* -----------------------------------------------------------------------------
+Software License for The Fraunhofer FDK AAC Codec Library for Android
+
+© Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
+Forschung e.V. All rights reserved.
+
+ 1. INTRODUCTION
+The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
+that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
+scheme for digital audio. This FDK AAC Codec software is intended to be used on
+a wide variety of Android devices.
+
+AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
+general perceptual audio codecs. AAC-ELD is considered the best-performing
+full-bandwidth communications codec by independent studies and is widely
+deployed. AAC has been standardized by ISO and IEC as part of the MPEG
+specifications.
+
+Patent licenses for necessary patent claims for the FDK AAC Codec (including
+those of Fraunhofer) may be obtained through Via Licensing
+(www.vialicensing.com) or through the respective patent owners individually for
+the purpose of encoding or decoding bit streams in products that are compliant
+with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
+Android devices already license these patent claims through Via Licensing or
+directly from the patent owners, and therefore FDK AAC Codec software may
+already be covered under those patent licenses when it is used for those
+licensed purposes only.
+
+Commercially-licensed AAC software libraries, including floating-point versions
+with enhanced sound quality, are also available from Fraunhofer. Users are
+encouraged to check the Fraunhofer website for additional applications
+information and documentation.
+
+2. COPYRIGHT LICENSE
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted without payment of copyright license fees provided that you
+satisfy the following conditions:
+
+You must retain the complete text of this software license in redistributions of
+the FDK AAC Codec or your modifications thereto in source code form.
+
+You must retain the complete text of this software license in the documentation
+and/or other materials provided with redistributions of the FDK AAC Codec or
+your modifications thereto in binary form. You must make available free of
+charge copies of the complete source code of the FDK AAC Codec and your
+modifications thereto to recipients of copies in binary form.
+
+The name of Fraunhofer may not be used to endorse or promote products derived
+from this library without prior written permission.
+
+You may not charge copyright license fees for anyone to use, copy or distribute
+the FDK AAC Codec software or your modifications thereto.
+
+Your modified versions of the FDK AAC Codec must carry prominent notices stating
+that you changed the software and the date of any change. For modified versions
+of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
+must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
+AAC Codec Library for Android."
+
+3. NO PATENT LICENSE
+
+NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
+limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
+Fraunhofer provides no warranty of patent non-infringement with respect to this
+software.
+
+You may use this FDK AAC Codec software or modifications thereto only for
+purposes that are authorized by appropriate patent licenses.
+
+4. DISCLAIMER
+
+This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
+holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
+including but not limited to the implied warranties of merchantability and
+fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
+or consequential damages, including but not limited to procurement of substitute
+goods or services; loss of use, data, or profits, or business interruption,
+however caused and on any theory of liability, whether in contract, strict
+liability, or tort (including negligence), arising in any way out of the use of
+this software, even if advised of the possibility of such damage.
+
+5. CONTACT INFORMATION
+
+Fraunhofer Institute for Integrated Circuits IIS
+Attention: Audio and Multimedia Departments - FDK AAC LL
+Am Wolfsmantel 33
+91058 Erlangen, Germany
+
+www.iis.fraunhofer.de/amm
+amm-info@iis.fraunhofer.de
+----------------------------------------------------------------------------- */
+
+/**************************** SBR encoder library ******************************
+
+ Author(s):
+
+ Description:
+
+*******************************************************************************/
+
+/*!
+ \file
+ \brief frequency scale $Revision: 95225 $
+*/
+
+#include "sbrenc_freq_sca.h"
+#include "sbr_misc.h"
+
+#include "genericStds.h"
+
+/* StartFreq */
+static INT getStartFreq(INT fsCore, const INT start_freq);
+
+/* StopFreq */
+static INT getStopFreq(INT fsCore, const INT stop_freq);
+
+static INT numberOfBands(INT b_p_o, INT start, INT stop, FIXP_DBL warp_factor);
+static void CalcBands(INT *diff, INT start, INT stop, INT num_bands);
+static INT modifyBands(INT max_band, INT *diff, INT length);
+static void cumSum(INT start_value, INT *diff, INT length, UCHAR *start_adress);
+
+/*******************************************************************************
+ Functionname: FDKsbrEnc_getSbrStartFreqRAW
+ *******************************************************************************
+ Description:
+
+ Arguments:
+
+ Return:
+ *******************************************************************************/
+
+INT FDKsbrEnc_getSbrStartFreqRAW(INT startFreq, INT fsCore) {
+ INT result;
+
+ if (startFreq < 0 || startFreq > 15) {
+ return -1;
+ }
+ /* Update startFreq struct */
+ result = getStartFreq(fsCore, startFreq);
+
+ result =
+ (result * (fsCore >> 5) + 1) >> 1; /* (result*fsSBR/QMFbands+1)>>1; */
+
+ return (result);
+
+} /* End FDKsbrEnc_getSbrStartFreqRAW */
+
+/*******************************************************************************
+ Functionname: getSbrStopFreq
+ *******************************************************************************
+ Description:
+
+ Arguments:
+
+ Return:
+ *******************************************************************************/
+INT FDKsbrEnc_getSbrStopFreqRAW(INT stopFreq, INT fsCore) {
+ INT result;
+
+ if (stopFreq < 0 || stopFreq > 13) return -1;
+
+ /* Uppdate stopFreq struct */
+ result = getStopFreq(fsCore, stopFreq);
+ result =
+ (result * (fsCore >> 5) + 1) >> 1; /* (result*fsSBR/QMFbands+1)>>1; */
+
+ return (result);
+} /* End getSbrStopFreq */
+
+/*******************************************************************************
+ Functionname: getStartFreq
+ *******************************************************************************
+ Description:
+
+ Arguments: fsCore - core sampling rate
+
+
+ Return:
+ *******************************************************************************/
+static INT getStartFreq(INT fsCore, const INT start_freq) {
+ INT k0_min;
+
+ switch (fsCore) {
+ case 8000:
+ k0_min = 24; /* (3000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 11025:
+ k0_min = 17; /* (3000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 12000:
+ k0_min = 16; /* (3000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 16000:
+ k0_min = 16; /* (4000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 22050:
+ k0_min = 12; /* (4000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 24000:
+ k0_min = 11; /* (4000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 32000:
+ k0_min = 10; /* (5000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 44100:
+ k0_min = 7; /* (5000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 48000:
+ k0_min = 7; /* (5000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ case 96000:
+ k0_min = 3; /* (5000 * nQmfChannels / fsSBR ) + 0.5 */
+ break;
+ default:
+ k0_min = 11; /* illegal fs */
+ }
+
+ switch (fsCore) {
+ case 8000: {
+ INT v_offset[] = {-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7};
+ return (k0_min + v_offset[start_freq]);
+ }
+ case 11025: {
+ INT v_offset[] = {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13};
+ return (k0_min + v_offset[start_freq]);
+ }
+ case 12000: {
+ INT v_offset[] = {-5, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16};
+ return (k0_min + v_offset[start_freq]);
+ }
+ case 16000: {
+ INT v_offset[] = {-6, -4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16};
+ return (k0_min + v_offset[start_freq]);
+ }
+ case 22050:
+ case 24000:
+ case 32000: {
+ INT v_offset[] = {-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20};
+ return (k0_min + v_offset[start_freq]);
+ }
+ case 44100:
+ case 48000:
+ case 96000: {
+ INT v_offset[] = {-2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24};
+ return (k0_min + v_offset[start_freq]);
+ }
+ default: {
+ INT v_offset[] = {0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24, 28, 33};
+ return (k0_min + v_offset[start_freq]);
+ }
+ }
+} /* End getStartFreq */
+
+/*******************************************************************************
+ Functionname: getStopFreq
+ *******************************************************************************
+ Description:
+
+ Arguments:
+
+ Return:
+ *******************************************************************************/
+static INT getStopFreq(INT fsCore, const INT stop_freq) {
+ INT result, i;
+ INT k1_min;
+ INT v_dstop[13];
+
+ INT *v_stop_freq = NULL;
+ INT v_stop_freq_16[14] = {48, 49, 50, 51, 52, 54, 55,
+ 56, 57, 59, 60, 61, 63, 64};
+ INT v_stop_freq_22[14] = {35, 37, 38, 40, 42, 44, 46,
+ 48, 51, 53, 56, 58, 61, 64};
+ INT v_stop_freq_24[14] = {32, 34, 36, 38, 40, 42, 44,
+ 46, 49, 52, 55, 58, 61, 64};
+ INT v_stop_freq_32[14] = {32, 34, 36, 38, 40, 42, 44,
+ 46, 49, 52, 55, 58, 61, 64};
+ INT v_stop_freq_44[14] = {23, 25, 27, 29, 32, 34, 37,
+ 40, 43, 47, 51, 55, 59, 64};
+ INT v_stop_freq_48[14] = {21, 23, 25, 27, 30, 32, 35,
+ 38, 42, 45, 49, 54, 59, 64};
+ INT v_stop_freq_64[14] = {20, 22, 24, 26, 29, 31, 34,
+ 37, 41, 45, 49, 54, 59, 64};
+ INT v_stop_freq_88[14] = {15, 17, 19, 21, 23, 26, 29,
+ 33, 37, 41, 46, 51, 57, 64};
+ INT v_stop_freq_96[14] = {13, 15, 17, 19, 21, 24, 27,
+ 31, 35, 39, 44, 50, 57, 64};
+ INT v_stop_freq_192[14] = {7, 8, 10, 12, 14, 16, 19,
+ 23, 27, 32, 38, 46, 54, 64};
+
+ switch (fsCore) {
+ case 8000:
+ k1_min = 48;
+ v_stop_freq = v_stop_freq_16;
+ break;
+ case 11025:
+ k1_min = 35;
+ v_stop_freq = v_stop_freq_22;
+ break;
+ case 12000:
+ k1_min = 32;
+ v_stop_freq = v_stop_freq_24;
+ break;
+ case 16000:
+ k1_min = 32;
+ v_stop_freq = v_stop_freq_32;
+ break;
+ case 22050:
+ k1_min = 23;
+ v_stop_freq = v_stop_freq_44;
+ break;
+ case 24000:
+ k1_min = 21;
+ v_stop_freq = v_stop_freq_48;
+ break;
+ case 32000:
+ k1_min = 20;
+ v_stop_freq = v_stop_freq_64;
+ break;
+ case 44100:
+ k1_min = 15;
+ v_stop_freq = v_stop_freq_88;
+ break;
+ case 48000:
+ k1_min = 13;
+ v_stop_freq = v_stop_freq_96;
+ break;
+ case 96000:
+ k1_min = 7;
+ v_stop_freq = v_stop_freq_192;
+ break;
+ default:
+ k1_min = 21; /* illegal fs */
+ }
+
+ /* Ensure increasing bandwidth */
+ for (i = 0; i <= 12; i++) {
+ v_dstop[i] = v_stop_freq[i + 1] - v_stop_freq[i];
+ }
+
+ FDKsbrEnc_Shellsort_int(v_dstop, 13); /* Sort bandwidth changes */
+
+ result = k1_min;
+ for (i = 0; i < stop_freq; i++) {
+ result = result + v_dstop[i];
+ }
+
+ return (result);
+
+} /* End getStopFreq */
+
+/*******************************************************************************
+ Functionname: FDKsbrEnc_FindStartAndStopBand
+ *******************************************************************************
+ Description:
+
+ Arguments: srSbr SBR sampling freqency
+ srCore AAC core sampling freqency
+ noChannels Number of QMF channels
+ startFreq SBR start frequency in QMF bands
+ stopFreq SBR start frequency in QMF bands
+
+ *k0 Output parameter
+ *k2 Output parameter
+
+ Return: Error code (0 is OK)
+ *******************************************************************************/
+INT FDKsbrEnc_FindStartAndStopBand(const INT srSbr, const INT srCore,
+ const INT noChannels, const INT startFreq,
+ const INT stopFreq, INT *k0, INT *k2) {
+ /* Update startFreq struct */
+ *k0 = getStartFreq(srCore, startFreq);
+
+ /* Test if start freq is outside corecoder range */
+ if (srSbr * noChannels < *k0 * srCore) {
+ return (
+ 1); /* raise the cross-over frequency and/or lower the number
+ of target bands per octave (or lower the sampling frequency) */
+ }
+
+ /*Update stopFreq struct */
+ if (stopFreq < 14) {
+ *k2 = getStopFreq(srCore, stopFreq);
+ } else if (stopFreq == 14) {
+ *k2 = 2 * *k0;
+ } else {
+ *k2 = 3 * *k0;
+ }
+
+ /* limit to Nyqvist */
+ if (*k2 > noChannels) {
+ *k2 = noChannels;
+ }
+
+ /* Test for invalid k0 k2 combinations */
+ if ((srCore == 22050) && ((*k2 - *k0) > MAX_FREQ_COEFFS_FS44100))
+ return (1); /* Number of bands exceeds valid range of MAX_FREQ_COEFFS for
+ fs=44.1kHz */
+
+ if ((srCore >= 24000) && ((*k2 - *k0) > MAX_FREQ_COEFFS_FS48000))
+ return (1); /* Number of bands exceeds valid range of MAX_FREQ_COEFFS for
+ fs>=48kHz */
+
+ if ((*k2 - *k0) > MAX_FREQ_COEFFS)
+ return (1); /*Number of bands exceeds valid range of MAX_FREQ_COEFFS */
+
+ if ((*k2 - *k0) < 0) return (1); /* Number of bands is negative */
+
+ return (0);
+}
+
+/*******************************************************************************
+ Functionname: FDKsbrEnc_UpdateFreqScale
+ *******************************************************************************
+ Description:
+
+ Arguments:
+
+ Return:
+ *******************************************************************************/
+INT FDKsbrEnc_UpdateFreqScale(UCHAR *v_k_master, INT *h_num_bands, const INT k0,
+ const INT k2, const INT freqScale,
+ const INT alterScale)
+
+{
+ INT b_p_o = 0; /* bands_per_octave */
+ FIXP_DBL warp = FL2FXCONST_DBL(0.0f);
+ INT dk = 0;
+
+ /* Internal variables */
+ INT k1 = 0, i;
+ INT num_bands0;
+ INT num_bands1;
+ INT diff_tot[MAX_OCTAVE + MAX_SECOND_REGION];
+ INT *diff0 = diff_tot;
+ INT *diff1 = diff_tot + MAX_OCTAVE;
+ INT k2_achived;
+ INT k2_diff;
+ INT incr = 0;
+
+ /* Init */
+ if (freqScale == 1) b_p_o = 12;
+ if (freqScale == 2) b_p_o = 10;
+ if (freqScale == 3) b_p_o = 8;
+
+ if (freqScale > 0) /*Bark*/
+ {
+ if (alterScale == 0)
+ warp = FL2FXCONST_DBL(0.5f); /* 1.0/(1.0*2.0) */
+ else
+ warp = FL2FXCONST_DBL(1.0f / 2.6f); /* 1.0/(1.3*2.0); */
+
+ if (4 * k2 >= 9 * k0) /*two or more regions (how many times the basis band
+ is copied)*/
+ {
+ k1 = 2 * k0;
+
+ num_bands0 = numberOfBands(b_p_o, k0, k1, FL2FXCONST_DBL(0.5f));
+ num_bands1 = numberOfBands(b_p_o, k1, k2, warp);
+
+ CalcBands(diff0, k0, k1, num_bands0); /*CalcBands1 => diff0 */
+ FDKsbrEnc_Shellsort_int(diff0, num_bands0); /*SortBands sort diff0 */
+
+ if (diff0[0] == 0) /* too wide FB bands for target tuning */
+ {
+ return (1); /* raise the cross-over frequency and/or lower the number
+ of target bands per octave (or lower the sampling
+ frequency */
+ }
+
+ cumSum(k0, diff0, num_bands0, v_k_master); /* cumsum */
+
+ CalcBands(diff1, k1, k2, num_bands1); /* CalcBands2 => diff1 */
+ FDKsbrEnc_Shellsort_int(diff1, num_bands1); /* SortBands sort diff1 */
+ if (diff0[num_bands0 - 1] > diff1[0]) /* max(1) > min(2) */
+ {
+ if (modifyBands(diff0[num_bands0 - 1], diff1, num_bands1)) return (1);
+ }
+
+ /* Add 2'nd region */
+ cumSum(k1, diff1, num_bands1, &v_k_master[num_bands0]);
+ *h_num_bands = num_bands0 + num_bands1; /* Output nr of bands */
+
+ } else /* one region */
+ {
+ k1 = k2;
+
+ num_bands0 = numberOfBands(b_p_o, k0, k1, FL2FXCONST_DBL(0.5f));
+ CalcBands(diff0, k0, k1, num_bands0); /* CalcBands1 => diff0 */
+ FDKsbrEnc_Shellsort_int(diff0, num_bands0); /* SortBands sort diff0 */
+
+ if (diff0[0] == 0) /* too wide FB bands for target tuning */
+ {
+ return (1); /* raise the cross-over frequency and/or lower the number
+ of target bands per octave (or lower the sampling
+ frequency */
+ }
+
+ cumSum(k0, diff0, num_bands0, v_k_master); /* cumsum */
+ *h_num_bands = num_bands0; /* Output nr of bands */
+ }
+ } else /* Linear mode */
+ {
+ if (alterScale == 0) {
+ dk = 1;
+ num_bands0 = 2 * ((k2 - k0) / 2); /* FLOOR to get to few number of bands*/
+ } else {
+ dk = 2;
+ num_bands0 =
+ 2 * (((k2 - k0) / dk + 1) / 2); /* ROUND to get closest fit */
+ }
+
+ k2_achived = k0 + num_bands0 * dk;
+ k2_diff = k2 - k2_achived;
+
+ for (i = 0; i < num_bands0; i++) diff_tot[i] = dk;
+
+ /* If linear scale wasn't achived */
+ /* and we got wide SBR are */
+ if (k2_diff < 0) {
+ incr = 1;
+ i = 0;
+ }
+
+ /* If linear scale wasn't achived */
+ /* and we got small SBR are */
+ if (k2_diff > 0) {
+ incr = -1;
+ i = num_bands0 - 1;
+ }
+
+ /* Adjust diff vector to get sepc. SBR range */
+ while (k2_diff != 0) {
+ diff_tot[i] = diff_tot[i] - incr;
+ i = i + incr;
+ k2_diff = k2_diff + incr;
+ }
+
+ cumSum(k0, diff_tot, num_bands0, v_k_master); /* cumsum */
+ *h_num_bands = num_bands0; /* Output nr of bands */
+ }
+
+ if (*h_num_bands < 1) return (1); /*To small sbr area */
+
+ return (0);
+} /* End FDKsbrEnc_UpdateFreqScale */
+
+static INT numberOfBands(INT b_p_o, INT start, INT stop, FIXP_DBL warp_factor) {
+ INT result = 0;
+ /* result = 2* (INT) ( (double)b_p_o *
+ * (double)(FDKlog((double)stop/(double)start)/FDKlog((double)2)) *
+ * (double)FX_DBL2FL(warp_factor) + 0.5); */
+ result = ((b_p_o * fMult((CalcLdInt(stop) - CalcLdInt(start)), warp_factor) +
+ (FL2FX_DBL(0.5f) >> LD_DATA_SHIFT)) >>
+ ((DFRACT_BITS - 1) - LD_DATA_SHIFT))
+ << 1; /* do not optimize anymore (rounding!!) */
+
+ return (result);
+}
+
+static void CalcBands(INT *diff, INT start, INT stop, INT num_bands) {
+ INT i, qb, qe, qtmp;
+ INT previous;
+ INT current;
+ FIXP_DBL base, exp, tmp;
+
+ previous = start;
+ for (i = 1; i <= num_bands; i++) {
+ base = fDivNorm((FIXP_DBL)stop, (FIXP_DBL)start, &qb);
+ exp = fDivNorm((FIXP_DBL)i, (FIXP_DBL)num_bands, &qe);
+ tmp = fPow(base, qb, exp, qe, &qtmp);
+ tmp = fMult(tmp, (FIXP_DBL)(start << 24));
+ current = (INT)scaleValue(tmp, qtmp - 23);
+ current = (current + 1) >> 1; /* rounding*/
+ diff[i - 1] = current - previous;
+ previous = current;
+ }
+
+} /* End CalcBands */
+
+static void cumSum(INT start_value, INT *diff, INT length,
+ UCHAR *start_adress) {
+ INT i;
+ start_adress[0] = start_value;
+ for (i = 1; i <= length; i++)
+ start_adress[i] = start_adress[i - 1] + diff[i - 1];
+} /* End cumSum */
+
+static INT modifyBands(INT max_band_previous, INT *diff, INT length) {
+ INT change = max_band_previous - diff[0];
+
+ /* Limit the change so that the last band cannot get narrower than the first
+ * one */
+ if (change > (diff[length - 1] - diff[0]) / 2)
+ change = (diff[length - 1] - diff[0]) / 2;
+
+ diff[0] += change;
+ diff[length - 1] -= change;
+ FDKsbrEnc_Shellsort_int(diff, length);
+
+ return (0);
+} /* End modifyBands */
+
+/*******************************************************************************
+ Functionname: FDKsbrEnc_UpdateHiRes
+ *******************************************************************************
+ Description:
+
+
+ Arguments:
+
+ Return:
+ *******************************************************************************/
+INT FDKsbrEnc_UpdateHiRes(UCHAR *h_hires, INT *num_hires, UCHAR *v_k_master,
+ INT num_master, INT *xover_band) {
+ INT i;
+ INT max1, max2;
+
+ if ((v_k_master[*xover_band] >
+ 32) || /* v_k_master[*xover_band] > noQMFChannels(dualRate)/divider */
+ (*xover_band > num_master)) {
+ /* xover_band error, too big for this startFreq. Will be clipped */
+
+ /* Calculate maximum value for xover_band */
+ max1 = 0;
+ max2 = num_master;
+ while ((v_k_master[max1 + 1] < 32) && /* noQMFChannels(dualRate)/divider */
+ ((max1 + 1) < max2)) {
+ max1++;
+ }
+
+ *xover_band = max1;
+ }
+
+ *num_hires = num_master - *xover_band;
+ for (i = *xover_band; i <= num_master; i++) {
+ h_hires[i - *xover_band] = v_k_master[i];
+ }
+
+ return (0);
+} /* End FDKsbrEnc_UpdateHiRes */
+
+/*******************************************************************************
+ Functionname: FDKsbrEnc_UpdateLoRes
+ *******************************************************************************
+ Description:
+
+ Arguments:
+
+ Return:
+ *******************************************************************************/
+void FDKsbrEnc_UpdateLoRes(UCHAR *h_lores, INT *num_lores, UCHAR *h_hires,
+ INT num_hires) {
+ INT i;
+
+ if (num_hires % 2 == 0) /* if even number of hires bands */
+ {
+ *num_lores = num_hires / 2;
+ /* Use every second lores=hires[0,2,4...] */
+ for (i = 0; i <= *num_lores; i++) h_lores[i] = h_hires[i * 2];
+
+ } else /* odd number of hires which means xover is odd */
+ {
+ *num_lores = (num_hires + 1) / 2;
+
+ /* Use lores=hires[0,1,3,5 ...] */
+ h_lores[0] = h_hires[0];
+ for (i = 1; i <= *num_lores; i++) {
+ h_lores[i] = h_hires[i * 2 - 1];
+ }
+ }
+
+} /* End FDKsbrEnc_UpdateLoRes */