1
2/* -----------------------------------------------------------------------------------------------------------
3Software License for The Fraunhofer FDK AAC Codec Library for Android
4
5� Copyright  1995 - 2015 Fraunhofer-Gesellschaft zur F�rderung der angewandten Forschung e.V.
6  All rights reserved.
7
8 1.    INTRODUCTION
9The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
10the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
11This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
12
13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
14audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
15independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
16of the MPEG specifications.
17
18Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
19may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
20individually for the purpose of encoding or decoding bit streams in products that are compliant with
21the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
22these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
23software may already be covered under those patent licenses when it is used for those licensed purposes only.
24
25Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
26are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
27applications information and documentation.
28
292.    COPYRIGHT LICENSE
30
31Redistribution and use in source and binary forms, with or without modification, are permitted without
32payment of copyright license fees provided that you satisfy the following conditions:
33
34You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
35your modifications thereto in source code form.
36
37You must retain the complete text of this software license in the documentation and/or other materials
38provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
39You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
40modifications thereto to recipients of copies in binary form.
41
42The name of Fraunhofer may not be used to endorse or promote products derived from this library without
43prior written permission.
44
45You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
46software or your modifications thereto.
47
48Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
49and the date of any change. For modified versions of the FDK AAC Codec, the term
50"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
51"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
52
533.    NO PATENT LICENSE
54
55NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
56ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
57respect to this software.
58
59You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
60by appropriate patent licenses.
61
624.    DISCLAIMER
63
64This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
65"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
66of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
67CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
68including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
69or business interruption, however caused and on any theory of liability, whether in contract, strict
70liability, or tort (including negligence), arising in any way out of the use of this software, even if
71advised of the possibility of such damage.
72
735.    CONTACT INFORMATION
74
75Fraunhofer Institute for Integrated Circuits IIS
76Attention: Audio and Multimedia Departments - FDK AAC LL
77Am Wolfsmantel 33
7891058 Erlangen, Germany
79
80www.iis.fraunhofer.de/amm
81amm-info@iis.fraunhofer.de
82----------------------------------------------------------------------------------------------------------- */
83
84/******************************** MPEG Audio Encoder **************************
85
86   Initial author:       A. Horndasch (code originally from lwr) / Josef Hoepfl (FDK)
87   contents/description: intensity stereo processing
88
89******************************************************************************/
90
91#include "intensity.h"
92#include "interface.h"
93#include "psy_configuration.h"
94#include "psy_const.h"
95#include "qc_main.h"
96#include "bit_cnt.h"
97
98/* only set an IS seed it left/right channel correlation is above IS_CORR_THRESH */
99#define IS_CORR_THRESH                FL2FXCONST_DBL(0.95f)
100
101/* when expanding the IS region to more SFBs only accept an error that is
102 * not more than IS_TOTAL_ERROR_THRESH overall and
103 * not more than IS_LOCAL_ERROR_THRESH for the current SFB */
104#define IS_TOTAL_ERROR_THRESH         FL2FXCONST_DBL(0.04f)
105#define IS_LOCAL_ERROR_THRESH         FL2FXCONST_DBL(0.01f)
106
107/* the maximum allowed change of the intensity direction (unit: IS scale) - scaled with factor 0.25 - */
108#define IS_DIRECTION_DEVIATION_THRESH_SF 2
109#define IS_DIRECTION_DEVIATION_THRESH FL2FXCONST_DBL(2.0f/(1<<IS_DIRECTION_DEVIATION_THRESH_SF))
110
111/* IS regions need to have a minimal percentage of the overall loudness, e.g. 0.06 == 6% */
112#define IS_REGION_MIN_LOUDNESS        FL2FXCONST_DBL(0.1f)
113
114/* only perform IS if IS_MIN_SFBS neighboring SFBs can be processed */
115#define IS_MIN_SFBS                   6
116
117/* only do IS if
118 * if IS_LEFT_RIGHT_RATIO_THRESH < sfbEnergyLeft[sfb]/sfbEnergyRight[sfb] < 1 / IS_LEFT_RIGHT_RATIO_THRESH
119 * -> no IS if the panning angle is not far from the middle, MS will do */
120/* this is equivalent to a scale of +/-1.02914634566 */
121#define IS_LEFT_RIGHT_RATIO_THRESH    FL2FXCONST_DBL(0.7f)
122
123/* scalefactor of realScale */
124#define REAL_SCALE_SF                    1
125
126/* scalefactor overallLoudness */
127#define OVERALL_LOUDNESS_SF              6
128
129/* scalefactor for sum over max samples per goup */
130#define MAX_SFB_PER_GROUP_SF             6
131
132/* scalefactor for sum of mdct spectrum */
133#define MDCT_SPEC_SF                     6
134
135
136typedef struct
137{
138
139  FIXP_DBL corr_thresh;                 /*!< Only set an IS seed it left/right channel correlation is above corr_thresh */
140
141  FIXP_DBL total_error_thresh;          /*!< When expanding the IS region to more SFBs only accept an error that is
142                                             not more than 'total_error_thresh' overall. */
143
144  FIXP_DBL local_error_thresh;          /*!< When expanding the IS region to more SFBs only accept an error that is
145                                             not more than 'local_error_thresh' for the current SFB. */
146
147  FIXP_DBL direction_deviation_thresh;  /*!< The maximum allowed change of the intensity direction (unit: IS scale) */
148
149  FIXP_DBL is_region_min_loudness;      /*!< IS regions need to have a minimal percentage of the overall loudness, e.g. 0.06 == 6% */
150
151  INT      min_is_sfbs;                 /*!< Only perform IS if 'min_is_sfbs' neighboring SFBs can be processed */
152
153  FIXP_DBL left_right_ratio_threshold;  /*!< No IS if the panning angle is not far from the middle, MS will do */
154
155} INTENSITY_PARAMETERS;
156
157
158/*****************************************************************************
159
160    functionname: calcSfbMaxScale
161
162    description:  Calc max value in scalefactor band
163
164    input:        *mdctSpectrum
165                   l1
166                   l2
167
168    output:       none
169
170    returns:      scalefactor
171
172*****************************************************************************/
173static INT
174calcSfbMaxScale(const FIXP_DBL *mdctSpectrum,
175                const INT       l1,
176                const INT       l2)
177{
178  INT i;
179  INT sfbMaxScale;
180  FIXP_DBL maxSpc;
181
182  maxSpc = FL2FXCONST_DBL(0.0);
183  for (i=l1; i<l2; i++) {
184    FIXP_DBL tmp = fixp_abs((FIXP_DBL)mdctSpectrum[i]);
185    maxSpc = fixMax(maxSpc, tmp);
186  }
187  sfbMaxScale = (maxSpc==FL2FXCONST_DBL(0.0)) ? (DFRACT_BITS-2) : CntLeadingZeros(maxSpc)-1;
188
189  return sfbMaxScale;
190 }
191
192
193/*****************************************************************************
194
195    functionname: FDKaacEnc_initIsParams
196
197    description:  Initialization of intensity parameters
198
199    input:        isParams
200
201    output:       isParams
202
203    returns:      none
204
205*****************************************************************************/
206static void
207FDKaacEnc_initIsParams(INTENSITY_PARAMETERS *isParams)
208{
209  isParams->corr_thresh                = IS_CORR_THRESH;
210  isParams->total_error_thresh         = IS_TOTAL_ERROR_THRESH;
211  isParams->local_error_thresh         = IS_LOCAL_ERROR_THRESH;
212  isParams->direction_deviation_thresh = IS_DIRECTION_DEVIATION_THRESH;
213  isParams->is_region_min_loudness     = IS_REGION_MIN_LOUDNESS;
214  isParams->min_is_sfbs                = IS_MIN_SFBS;
215  isParams->left_right_ratio_threshold = IS_LEFT_RIGHT_RATIO_THRESH;
216}
217
218
219/*****************************************************************************
220
221    functionname: FDKaacEnc_prepareIntensityDecision
222
223    description:  Prepares intensity decision
224
225    input:        sfbEnergyLeft
226                  sfbEnergyRight
227                  sfbEnergyLdDataLeft
228                  sfbEnergyLdDataRight
229                  mdctSpectrumLeft
230                  sfbEnergyLdDataRight
231                  isParams
232
233    output:       hrrErr            scale: none
234                  isMask            scale: none
235                  realScale         scale: LD_DATA_SHIFT + REAL_SCALE_SF
236                  normSfbLoudness   scale: none
237
238    returns:      none
239
240*****************************************************************************/
241static void
242FDKaacEnc_prepareIntensityDecision(const FIXP_DBL    *sfbEnergyLeft,
243                                   const FIXP_DBL    *sfbEnergyRight,
244                                   const FIXP_DBL    *sfbEnergyLdDataLeft,
245                                   const FIXP_DBL    *sfbEnergyLdDataRight,
246                                   const FIXP_DBL    *mdctSpectrumLeft,
247                                   const FIXP_DBL    *mdctSpectrumRight,
248                                   const INTENSITY_PARAMETERS *isParams,
249                                   FIXP_DBL    *hrrErr,
250                                   INT         *isMask,
251                                   FIXP_DBL    *realScale,
252                                   FIXP_DBL    *normSfbLoudness,
253                                   const INT    sfbCnt,
254                                   const INT    sfbPerGroup,
255                                   const INT    maxSfbPerGroup,
256                                   const INT   *sfbOffset)
257{
258  INT j,sfb,sfboffs;
259  INT grpCounter;
260
261  /* temporary variables to compute loudness */
262  FIXP_DBL overallLoudness[MAX_NO_OF_GROUPS];
263
264  /* temporary variables to compute correlation */
265  FIXP_DBL channelCorr[MAX_GROUPED_SFB];
266  FIXP_DBL ml, mr;
267  FIXP_DBL prod_lr;
268  FIXP_DBL square_l, square_r;
269  FIXP_DBL tmp_l, tmp_r;
270  FIXP_DBL inv_n;
271
272  FDKmemclear(channelCorr,     MAX_GROUPED_SFB*sizeof(FIXP_DBL));
273  FDKmemclear(normSfbLoudness, MAX_GROUPED_SFB*sizeof(FIXP_DBL));
274  FDKmemclear(overallLoudness, MAX_NO_OF_GROUPS*sizeof(FIXP_DBL));
275  FDKmemclear(realScale,       MAX_GROUPED_SFB*sizeof(FIXP_DBL));
276
277  for (grpCounter = 0, sfboffs = 0; sfboffs < sfbCnt; sfboffs += sfbPerGroup, grpCounter++) {
278    overallLoudness[grpCounter] = FL2FXCONST_DBL(0.0f);
279    for (sfb = 0; sfb < maxSfbPerGroup; sfb++) {
280      INT sL,sR,s;
281      FIXP_DBL isValue = sfbEnergyLdDataLeft[sfb+sfboffs]-sfbEnergyLdDataRight[sfb+sfboffs];
282
283      /* delimitate intensity scale value to representable range */
284      realScale[sfb + sfboffs] = fixMin(FL2FXCONST_DBL(60.f/(1<<(REAL_SCALE_SF+LD_DATA_SHIFT))), fixMax(FL2FXCONST_DBL(-60.f/(1<<(REAL_SCALE_SF+LD_DATA_SHIFT))), isValue));
285
286      sL = fixMax(0,(CntLeadingZeros(sfbEnergyLeft[sfb + sfboffs])-1));
287      sR = fixMax(0,(CntLeadingZeros(sfbEnergyRight[sfb + sfboffs])-1));
288      s  = (fixMin(sL,sR)>>2)<<2;
289      normSfbLoudness[sfb + sfboffs] = sqrtFixp(sqrtFixp(((sfbEnergyLeft[sfb + sfboffs]<<s) >> 1) + ((sfbEnergyRight[sfb + sfboffs]<<s) >> 1))) >> (s>>2);
290
291      overallLoudness[grpCounter] += normSfbLoudness[sfb + sfboffs] >> OVERALL_LOUDNESS_SF;
292      /* don't do intensity if
293       * - panning angle is too close to the middle or
294       * - one channel is non-existent or
295       * - if it is dual mono */
296      if(   (sfbEnergyLeft[sfb + sfboffs] >= fMult(isParams->left_right_ratio_threshold,sfbEnergyRight[sfb + sfboffs]))
297         && (fMult(isParams->left_right_ratio_threshold,sfbEnergyLeft[sfb + sfboffs]) <= sfbEnergyRight[sfb + sfboffs]) ) {
298
299        /* this will prevent post processing from considering this SFB for merging */
300        hrrErr[sfb + sfboffs] = FL2FXCONST_DBL(1.0/8.0);
301      }
302    }
303  }
304
305  for (grpCounter = 0, sfboffs = 0; sfboffs < sfbCnt; sfboffs += sfbPerGroup, grpCounter++) {
306    INT invOverallLoudnessSF;
307    FIXP_DBL invOverallLoudness;
308
309    if (overallLoudness[grpCounter] == FL2FXCONST_DBL(0.0)) {
310      invOverallLoudness = FL2FXCONST_DBL(0.0);
311      invOverallLoudnessSF = 0;
312    }
313    else {
314      invOverallLoudness = fDivNorm((FIXP_DBL)MAXVAL_DBL, overallLoudness[grpCounter],&invOverallLoudnessSF);
315      invOverallLoudnessSF = invOverallLoudnessSF - OVERALL_LOUDNESS_SF + 1; /* +1: compensate fMultDiv2() in subsequent loop */
316    }
317    invOverallLoudnessSF = fixMin(fixMax(invOverallLoudnessSF,-(DFRACT_BITS-1)),DFRACT_BITS-1);
318
319    for (sfb = 0; sfb < maxSfbPerGroup; sfb++) {
320      FIXP_DBL tmp;
321
322      tmp = fMultDiv2((normSfbLoudness[sfb + sfboffs]>>OVERALL_LOUDNESS_SF)<<OVERALL_LOUDNESS_SF,invOverallLoudness);
323
324      normSfbLoudness[sfb + sfboffs] = scaleValue(tmp, invOverallLoudnessSF);
325
326      channelCorr[sfb + sfboffs] = FL2FXCONST_DBL(0.0f);
327
328      /* max width of scalefactorband is 96; width's are always even */
329      /* inv_n is scaled with factor 2 to compensate fMultDiv2() in subsequent loops */
330      inv_n = GetInvInt((sfbOffset[sfb + sfboffs + 1] - sfbOffset[sfb + sfboffs])>>1);
331
332      if (inv_n > FL2FXCONST_DBL(0.0f)) {
333        INT s,sL,sR;
334
335        /* correlation := Pearson's product-moment coefficient */
336        /* compute correlation between channels and check if it is over threshold */
337        ml       = FL2FXCONST_DBL(0.0f);
338        mr       = FL2FXCONST_DBL(0.0f);
339        prod_lr  = FL2FXCONST_DBL(0.0f);
340        square_l = FL2FXCONST_DBL(0.0f);
341        square_r = FL2FXCONST_DBL(0.0f);
342
343        sL = calcSfbMaxScale(mdctSpectrumLeft,sfbOffset[sfb+sfboffs],sfbOffset[sfb+sfboffs+1]);
344        sR = calcSfbMaxScale(mdctSpectrumRight,sfbOffset[sfb+sfboffs],sfbOffset[sfb+sfboffs+1]);
345        s = fixMin(sL,sR);
346
347        for (j = sfbOffset[sfb + sfboffs]; j < sfbOffset[sfb + sfboffs + 1]; j++) {
348          ml += fMultDiv2((mdctSpectrumLeft[j]  << s),inv_n);             // scaled with mdctScale - s + inv_n
349          mr += fMultDiv2((mdctSpectrumRight[j] << s),inv_n);             // scaled with mdctScale - s + inv_n
350        }
351        ml = fMultDiv2(ml,inv_n);                                         // scaled with mdctScale - s + inv_n
352        mr = fMultDiv2(mr,inv_n);                                         // scaled with mdctScale - s + inv_n
353
354        for (j = sfbOffset[sfb + sfboffs]; j < sfbOffset[sfb + sfboffs + 1]; j++) {
355          tmp_l = fMultDiv2((mdctSpectrumLeft[j]  << s),inv_n) - ml;      // scaled with mdctScale - s + inv_n
356          tmp_r = fMultDiv2((mdctSpectrumRight[j] << s),inv_n) - mr;      // scaled with mdctScale - s + inv_n
357
358          prod_lr  += fMultDiv2(tmp_l,tmp_r);                             // scaled with 2*(mdctScale - s + inv_n) + 1
359          square_l += fPow2Div2(tmp_l);                                   // scaled with 2*(mdctScale - s + inv_n) + 1
360          square_r += fPow2Div2(tmp_r);                                   // scaled with 2*(mdctScale - s + inv_n) + 1
361        }
362        prod_lr  = prod_lr  << 1;                                         // scaled with 2*(mdctScale - s + inv_n)
363        square_l = square_l << 1;                                         // scaled with 2*(mdctScale - s + inv_n)
364        square_r = square_r << 1;                                         // scaled with 2*(mdctScale - s + inv_n)
365
366        if (square_l > FL2FXCONST_DBL(0.0f) && square_r > FL2FXCONST_DBL(0.0f)) {
367          INT channelCorrSF = 0;
368
369          /* local scaling of square_l and square_r is compensated after sqrt calculation */
370          sL  = fixMax(0,(CntLeadingZeros(square_l)-1));
371          sR  = fixMax(0,(CntLeadingZeros(square_r)-1));
372          s   = ((sL + sR)>>1)<<1;
373          sL  = fixMin(sL,s);
374          sR  = s-sL;
375          tmp = fMult(square_l<<sL,square_r<<sR);
376          tmp = sqrtFixp(tmp);
377
378          FDK_ASSERT(tmp > FL2FXCONST_DBL(0.0f));
379
380          /* numerator and denominator have the same scaling */
381          if (prod_lr < FL2FXCONST_DBL(0.0f) ) {
382            channelCorr[sfb + sfboffs] = -(fDivNorm(-prod_lr,tmp,&channelCorrSF));
383
384          }
385          else {
386            channelCorr[sfb + sfboffs] =  (fDivNorm( prod_lr,tmp,&channelCorrSF));
387          }
388          channelCorrSF = fixMin(fixMax(( channelCorrSF + ((sL+sR)>>1)),-(DFRACT_BITS-1)),DFRACT_BITS-1);
389
390          if (channelCorrSF < 0) {
391            channelCorr[sfb + sfboffs] = channelCorr[sfb + sfboffs] >> (-channelCorrSF);
392          }
393          else {
394            /* avoid overflows due to limited computational accuracy */
395            if ( fAbs(channelCorr[sfb + sfboffs]) > (((FIXP_DBL)MAXVAL_DBL)>>channelCorrSF) ) {
396              if (channelCorr[sfb + sfboffs] < FL2FXCONST_DBL(0.0f))
397                channelCorr[sfb + sfboffs] = -(FIXP_DBL) MAXVAL_DBL;
398              else
399                channelCorr[sfb + sfboffs] =  (FIXP_DBL) MAXVAL_DBL;
400            }
401            else {
402              channelCorr[sfb + sfboffs] = channelCorr[sfb + sfboffs] << channelCorrSF;
403            }
404          }
405        }
406      }
407
408      /* for post processing: hrrErr is the error in terms of (too little) correlation
409       * weighted with the loudness of the SFB; SFBs with small hrrErr can be merged */
410      if (hrrErr[sfb + sfboffs] == FL2FXCONST_DBL(1.0/8.0)) {
411        continue;
412      }
413
414      hrrErr[sfb + sfboffs] = fMultDiv2((FL2FXCONST_DBL(0.25f)-(channelCorr[sfb + sfboffs]>>2)),normSfbLoudness[sfb + sfboffs]);
415
416      /* set IS mask/vector to 1, if correlation is high enough */
417      if (fAbs(channelCorr[sfb + sfboffs]) >= isParams->corr_thresh) {
418        isMask[sfb + sfboffs] = 1;
419      }
420    }
421  }
422}
423
424
425/*****************************************************************************
426
427    functionname: FDKaacEnc_finalizeIntensityDecision
428
429    description:  Finalizes intensity decision
430
431    input:        isParams          scale: none
432                  hrrErr            scale: none
433                  realIsScale       scale: LD_DATA_SHIFT + REAL_SCALE_SF
434                  normSfbLoudness   scale: none
435
436    output:       isMask            scale: none
437
438    returns:      none
439
440*****************************************************************************/
441static void
442FDKaacEnc_finalizeIntensityDecision(const FIXP_DBL *hrrErr,
443                                    INT            *isMask,
444                                    const FIXP_DBL *realIsScale,
445                                    const FIXP_DBL *normSfbLoudness,
446                                    const INTENSITY_PARAMETERS *isParams,
447                                    const INT       sfbCnt,
448                                    const INT       sfbPerGroup,
449                                    const INT       maxSfbPerGroup)
450{
451  INT sfb,sfboffs, j;
452  FIXP_DBL isScaleLast = FL2FXCONST_DBL(0.0f);
453  INT isStartValueFound = 0;
454
455  for (sfboffs = 0; sfboffs < sfbCnt; sfboffs += sfbPerGroup) {
456    INT startIsSfb = 0;
457    INT inIsBlock = 0;
458    INT currentIsSfbCount = 0;
459    FIXP_DBL overallHrrError = FL2FXCONST_DBL(0.0f);
460    FIXP_DBL isRegionLoudness = FL2FXCONST_DBL(0.0f);
461
462    for (sfb = 0; sfb < maxSfbPerGroup; sfb++) {
463      if (isMask[sfboffs + sfb] == 1) {
464        if (currentIsSfbCount == 0) {
465          startIsSfb = sfboffs + sfb;
466        }
467        if (isStartValueFound==0) {
468          isScaleLast = realIsScale[sfboffs + sfb];
469          isStartValueFound = 1;
470        }
471        inIsBlock = 1;
472        currentIsSfbCount++;
473        overallHrrError  += hrrErr[sfboffs + sfb] >> (MAX_SFB_PER_GROUP_SF-3);
474        isRegionLoudness += normSfbLoudness[sfboffs + sfb] >> MAX_SFB_PER_GROUP_SF;
475      }
476      else {
477        /* based on correlation, IS should not be used
478         * -> use it anyway, if overall error is below threshold
479         *    and if local error does not exceed threshold
480         * otherwise: check if there are enough IS SFBs
481         */
482        if (inIsBlock) {
483          overallHrrError  += hrrErr[sfboffs + sfb] >> (MAX_SFB_PER_GROUP_SF-3);
484          isRegionLoudness += normSfbLoudness[sfboffs + sfb] >> MAX_SFB_PER_GROUP_SF;
485
486          if ( (hrrErr[sfboffs + sfb] < (isParams->local_error_thresh>>3)) && (overallHrrError < (isParams->total_error_thresh>>MAX_SFB_PER_GROUP_SF)) ) {
487            currentIsSfbCount++;
488            /* overwrite correlation based decision */
489            isMask[sfboffs + sfb] = 1;
490          } else {
491            inIsBlock = 0;
492          }
493        }
494      }
495      /* check for large direction deviation */
496      if (inIsBlock) {
497        if( fAbs(isScaleLast-realIsScale[sfboffs + sfb]) < (isParams->direction_deviation_thresh>>(REAL_SCALE_SF+LD_DATA_SHIFT-IS_DIRECTION_DEVIATION_THRESH_SF)) ) {
498          isScaleLast = realIsScale[sfboffs + sfb];
499        }
500        else{
501          isMask[sfboffs + sfb] = 0;
502          inIsBlock = 0;
503          currentIsSfbCount--;
504        }
505      }
506
507      if (currentIsSfbCount > 0 && (!inIsBlock || sfb == maxSfbPerGroup - 1)) {
508        /* not enough SFBs -> do not use IS */
509        if (currentIsSfbCount < isParams->min_is_sfbs || (isRegionLoudness < isParams->is_region_min_loudness>>MAX_SFB_PER_GROUP_SF)) {
510          for(j = startIsSfb; j <= sfboffs + sfb; j++) {
511            isMask[j] = 0;
512          }
513          isScaleLast = FL2FXCONST_DBL(0.0f);
514          isStartValueFound = 0;
515          for (j=0; j < startIsSfb; j++) {
516            if (isMask[j]!=0) {
517              isScaleLast = realIsScale[j];
518              isStartValueFound = 1;
519            }
520          }
521        }
522        currentIsSfbCount = 0;
523        overallHrrError = FL2FXCONST_DBL(0.0f);
524        isRegionLoudness = FL2FXCONST_DBL(0.0f);
525      }
526    }
527  }
528}
529
530
531/*****************************************************************************
532
533    functionname: FDKaacEnc_IntensityStereoProcessing
534
535    description:  Intensity stereo processing tool
536
537    input:        sfbEnergyLeft
538                  sfbEnergyRight
539                  mdctSpectrumLeft
540                  mdctSpectrumRight
541                  sfbThresholdLeft
542                  sfbThresholdRight
543                  sfbSpreadEnLeft
544                  sfbSpreadEnRight
545                  sfbEnergyLdDataLeft
546                  sfbEnergyLdDataRight
547
548    output:       isBook
549                  isScale
550                  pnsData->pnsFlag
551                  msDigest                 zeroed from start to sfbCnt
552                  msMask                   zeroed from start to sfbCnt
553                  mdctSpectrumRight        zeroed where isBook!=0
554                  sfbEnergyRight           zeroed where isBook!=0
555                  sfbSpreadEnRight       zeroed where isBook!=0
556                  sfbThresholdRight        zeroed where isBook!=0
557                  sfbEnergyLdDataRight     FL2FXCONST_DBL(-1.0) where isBook!=0
558                  sfbThresholdLdDataRight  FL2FXCONST_DBL(-0.515625f) where isBook!=0
559
560    returns:      none
561
562*****************************************************************************/
563void FDKaacEnc_IntensityStereoProcessing(
564        FIXP_DBL                  *sfbEnergyLeft,
565        FIXP_DBL                  *sfbEnergyRight,
566        FIXP_DBL                  *mdctSpectrumLeft,
567        FIXP_DBL                  *mdctSpectrumRight,
568        FIXP_DBL                  *sfbThresholdLeft,
569        FIXP_DBL                  *sfbThresholdRight,
570        FIXP_DBL                  *sfbThresholdLdDataRight,
571        FIXP_DBL                  *sfbSpreadEnLeft,
572        FIXP_DBL                  *sfbSpreadEnRight,
573        FIXP_DBL                  *sfbEnergyLdDataLeft,
574        FIXP_DBL                  *sfbEnergyLdDataRight,
575        INT                       *msDigest,
576        INT                       *msMask,
577        const INT                  sfbCnt,
578        const INT                  sfbPerGroup,
579        const INT                  maxSfbPerGroup,
580        const INT                 *sfbOffset,
581        const INT                  allowIS,
582        INT                       *isBook,
583        INT                       *isScale,
584        PNS_DATA         *RESTRICT pnsData[2]
585        )
586{
587  INT sfb,sfboffs, j;
588  FIXP_DBL scale;
589  FIXP_DBL lr;
590  FIXP_DBL hrrErr[MAX_GROUPED_SFB];
591  FIXP_DBL normSfbLoudness[MAX_GROUPED_SFB];
592  FIXP_DBL realIsScale[MAX_GROUPED_SFB];
593  INTENSITY_PARAMETERS isParams;
594  INT isMask[MAX_GROUPED_SFB];
595
596  FDKmemclear((void*)isBook,sfbCnt*sizeof(INT));
597  FDKmemclear((void*)isMask,sfbCnt*sizeof(INT));
598  FDKmemclear((void*)realIsScale,sfbCnt*sizeof(FIXP_DBL));
599  FDKmemclear((void*)isScale,sfbCnt*sizeof(INT));
600  FDKmemclear((void*)hrrErr,sfbCnt*sizeof(FIXP_DBL));
601
602  if (!allowIS)
603    return;
604
605  FDKaacEnc_initIsParams(&isParams);
606
607  /* compute / set the following values per SFB:
608   * - left/right ratio between channels
609   * - normalized loudness
610   *   + loudness == average of energy in channels to 0.25
611   *   + normalization: division by sum of all SFB loudnesses
612   * - isMask (is set to 0 if channels are the same or one is 0)
613   */
614   FDKaacEnc_prepareIntensityDecision(sfbEnergyLeft,
615                                      sfbEnergyRight,
616                                      sfbEnergyLdDataLeft,
617                                      sfbEnergyLdDataRight,
618                                      mdctSpectrumLeft,
619                                      mdctSpectrumRight,
620                                      &isParams,
621                                      hrrErr,
622                                      isMask,
623                                      realIsScale,
624                                      normSfbLoudness,
625                                      sfbCnt,
626                                      sfbPerGroup,
627                                      maxSfbPerGroup,
628                                      sfbOffset);
629
630  FDKaacEnc_finalizeIntensityDecision(hrrErr,
631                                      isMask,
632                                      realIsScale,
633                                      normSfbLoudness,
634                                      &isParams,
635                                      sfbCnt,
636                                      sfbPerGroup,
637                                      maxSfbPerGroup);
638
639  for (sfb=0; sfb<sfbCnt; sfb+=sfbPerGroup) {
640    for (sfboffs=0; sfboffs<maxSfbPerGroup; sfboffs++) {
641      INT sL, sR;
642      FIXP_DBL inv_n;
643
644      msMask[sfb+sfboffs] = 0;
645      if (isMask[sfb+sfboffs] == 0) {
646        continue;
647      }
648
649      if (   (sfbEnergyLeft[sfb+sfboffs] < sfbThresholdLeft[sfb+sfboffs])
650          &&(fMult(FL2FXCONST_DBL(1.0f/1.5f),sfbEnergyRight[sfb+sfboffs]) > sfbThresholdRight[sfb+sfboffs]) ) {
651        continue;
652      }
653      /* NEW: if there is a big-enough IS region, switch off PNS */
654      if (pnsData[0]) {
655        if(pnsData[0]->pnsFlag[sfb+sfboffs]) {
656          pnsData[0]->pnsFlag[sfb+sfboffs] = 0;
657        }
658        if(pnsData[1]->pnsFlag[sfb+sfboffs]) {
659          pnsData[1]->pnsFlag[sfb+sfboffs] = 0;
660        }
661      }
662
663      inv_n = GetInvInt((sfbOffset[sfb + sfboffs + 1] - sfbOffset[sfb + sfboffs])>>1);  // scaled with 2 to compensate fMultDiv2() in subsequent loop
664      sL = calcSfbMaxScale(mdctSpectrumLeft,sfbOffset[sfb+sfboffs],sfbOffset[sfb+sfboffs+1]);
665      sR = calcSfbMaxScale(mdctSpectrumRight,sfbOffset[sfb+sfboffs],sfbOffset[sfb+sfboffs+1]);
666
667      lr = FL2FXCONST_DBL(0.0f);
668      for (j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++)
669        lr += fMultDiv2(fMultDiv2(mdctSpectrumLeft[j]<<sL,mdctSpectrumRight[j]<<sR),inv_n);
670      lr = lr<<1;
671
672      if (lr < FL2FXCONST_DBL(0.0f)) {
673        /* This means OUT OF phase intensity stereo, cf. standard */
674        INT s0, s1, s2;
675        FIXP_DBL tmp, d, ed = FL2FXCONST_DBL(0.0f);
676
677        s0 = fixMin(sL,sR);
678        for (j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++) {
679          d = ((mdctSpectrumLeft[j]<<s0)>>1) - ((mdctSpectrumRight[j]<<s0)>>1);
680          ed += fMultDiv2(d,d)>>(MDCT_SPEC_SF-1);
681        }
682        msMask[sfb+sfboffs] = 1;
683        tmp = fDivNorm(sfbEnergyLeft[sfb+sfboffs],ed,&s1);
684        s2 = (s1) + (2*s0) - 2 - MDCT_SPEC_SF;
685        if (s2 & 1) {
686          tmp = tmp>>1;
687          s2 = s2+1;
688        }
689        s2 = (s2>>1) + 1;  // +1 compensate fMultDiv2() in subsequent loop
690        s2 = fixMin(fixMax(s2,-(DFRACT_BITS-1)),(DFRACT_BITS-1));
691        scale = sqrtFixp(tmp);
692        if (s2 < 0) {
693          s2 = -s2;
694          for (j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++) {
695            mdctSpectrumLeft[j] = (fMultDiv2(mdctSpectrumLeft[j],scale) - fMultDiv2(mdctSpectrumRight[j],scale)) >> s2;
696            mdctSpectrumRight[j] = FL2FXCONST_DBL(0.0f);
697          }
698        }
699        else {
700          for (j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++) {
701            mdctSpectrumLeft[j] = (fMultDiv2(mdctSpectrumLeft[j],scale) - fMultDiv2(mdctSpectrumRight[j],scale)) << s2;
702            mdctSpectrumRight[j] = FL2FXCONST_DBL(0.0f);
703          }
704        }
705      }
706      else {
707        /* This means IN phase intensity stereo, cf. standard */
708        INT s0,s1,s2;
709        FIXP_DBL tmp, s, es = FL2FXCONST_DBL(0.0f);
710
711        s0 = fixMin(sL,sR);
712        for (j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++) {
713          s   = ((mdctSpectrumLeft[j]<<s0)>>1) + ((mdctSpectrumRight[j]<<s0)>>1);
714          es += fMultDiv2(s,s)>>(MDCT_SPEC_SF-1);     // scaled 2*(mdctScale - s0 + 1) + MDCT_SPEC_SF
715        }
716        msMask[sfb+sfboffs] = 0;
717        tmp = fDivNorm(sfbEnergyLeft[sfb+sfboffs],es,&s1);
718        s2 = (s1) + (2*s0) - 2 - MDCT_SPEC_SF;
719        if (s2 & 1) {
720          tmp = tmp>>1;
721          s2 = s2 + 1;
722        }
723        s2 = (s2>>1) + 1; // +1 compensate fMultDiv2() in subsequent loop
724        s2 = fixMin(fixMax(s2,-(DFRACT_BITS-1)),(DFRACT_BITS-1));
725        scale = sqrtFixp(tmp);
726        if (s2 < 0) {
727          s2 = -s2;
728          for (j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++) {
729            mdctSpectrumLeft[j] = (fMultDiv2(mdctSpectrumLeft[j],scale) + fMultDiv2(mdctSpectrumRight[j],scale)) >> s2;
730            mdctSpectrumRight[j] = FL2FXCONST_DBL(0.0f);
731          }
732        }
733        else {
734          for (j=sfbOffset[sfb+sfboffs]; j<sfbOffset[sfb+sfboffs+1]; j++) {
735            mdctSpectrumLeft[j] = (fMultDiv2(mdctSpectrumLeft[j],scale) + fMultDiv2(mdctSpectrumRight[j],scale)) << s2;
736            mdctSpectrumRight[j] = FL2FXCONST_DBL(0.0f);
737          }
738        }
739      }
740
741      isBook[sfb+sfboffs] = CODE_BOOK_IS_IN_PHASE_NO;
742
743      if ( realIsScale[sfb+sfboffs] < FL2FXCONST_DBL(0.0f) ) {
744        isScale[sfb+sfboffs] = (INT)(((realIsScale[sfb+sfboffs]>>1)-FL2FXCONST_DBL(0.5f/(1<<(REAL_SCALE_SF+LD_DATA_SHIFT+1))))>>(DFRACT_BITS-1-REAL_SCALE_SF-LD_DATA_SHIFT-1)) + 1;
745      }
746      else {
747        isScale[sfb+sfboffs] = (INT)(((realIsScale[sfb+sfboffs]>>1)+FL2FXCONST_DBL(0.5f/(1<<(REAL_SCALE_SF+LD_DATA_SHIFT+1))))>>(DFRACT_BITS-1-REAL_SCALE_SF-LD_DATA_SHIFT-1));
748      }
749
750      sfbEnergyRight[sfb+sfboffs] = FL2FXCONST_DBL(0.0f);
751      sfbEnergyLdDataRight[sfb+sfboffs] = FL2FXCONST_DBL(-1.0f);
752      sfbThresholdRight[sfb+sfboffs] = FL2FXCONST_DBL(0.0f);
753      sfbThresholdLdDataRight[sfb+sfboffs] = FL2FXCONST_DBL(-0.515625f);
754      sfbSpreadEnRight[sfb+sfboffs] = FL2FXCONST_DBL(0.0f);
755
756      *msDigest = MS_SOME;
757    }
758  }
759}
760
761