1 
2 /* -----------------------------------------------------------------------------------------------------------
3 Software 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
9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
12 
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
16 of the MPEG specifications.
17 
18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
20 individually for the purpose of encoding or decoding bit streams in products that are compliant with
21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
23 software may already be covered under those patent licenses when it is used for those licensed purposes only.
24 
25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
27 applications information and documentation.
28 
29 2.    COPYRIGHT LICENSE
30 
31 Redistribution and use in source and binary forms, with or without modification, are permitted without
32 payment of copyright license fees provided that you satisfy the following conditions:
33 
34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
35 your modifications thereto in source code form.
36 
37 You must retain the complete text of this software license in the documentation and/or other materials
38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
40 modifications thereto to recipients of copies in binary form.
41 
42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without
43 prior written permission.
44 
45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
46 software or your modifications thereto.
47 
48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
49 and 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 
53 3.    NO PATENT LICENSE
54 
55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
57 respect to this software.
58 
59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
60 by appropriate patent licenses.
61 
62 4.    DISCLAIMER
63 
64 This 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
66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
69 or business interruption, however caused and on any theory of liability, whether in contract, strict
70 liability, or tort (including negligence), arising in any way out of the use of this software, even if
71 advised of the possibility of such damage.
72 
73 5.    CONTACT INFORMATION
74 
75 Fraunhofer Institute for Integrated Circuits IIS
76 Attention: Audio and Multimedia Departments - FDK AAC LL
77 Am Wolfsmantel 33
78 91058 Erlangen, Germany
79 
80 www.iis.fraunhofer.de/amm
81 amm-info@iis.fraunhofer.de
82 ----------------------------------------------------------------------------------------------------------- */
83 
84 /***************************  Fraunhofer IIS FDK Tools  **********************
85 
86    Author(s):   M. Gayer
87    Description: Fixed point specific mathematical functions
88 
89 ******************************************************************************/
90 
91 #ifndef __fixpoint_math_H
92 #define __fixpoint_math_H
93 
94 
95 #include "common_fix.h"
96 
97 #if !defined(FUNCTION_fIsLessThan)
98 /**
99  * \brief Compares two fixpoint values incl. scaling.
100  * \param a_m mantissa of the first input value.
101  * \param a_e exponent of the first input value.
102  * \param b_m mantissa of the second input value.
103  * \param b_e exponent of the second input value.
104  * \return non-zero if (a_m*2^a_e) < (b_m*2^b_e), 0 otherwise
105  */
fIsLessThan(FIXP_DBL a_m,INT a_e,FIXP_DBL b_m,INT b_e)106 FDK_INLINE INT fIsLessThan(FIXP_DBL a_m, INT a_e, FIXP_DBL b_m, INT b_e)
107 {
108   if (a_e > b_e) {
109     return (b_m >> fMin(a_e-b_e, DFRACT_BITS-1) > a_m);
110   } else {
111     return (a_m >> fMin(b_e-a_e, DFRACT_BITS-1) < b_m);
112   }
113 }
114 
fIsLessThan(FIXP_SGL a_m,INT a_e,FIXP_SGL b_m,INT b_e)115 FDK_INLINE INT fIsLessThan(FIXP_SGL a_m, INT a_e, FIXP_SGL b_m, INT b_e)
116 {
117   if (a_e > b_e) {
118     return (b_m >> fMin(a_e-b_e, FRACT_BITS-1) > a_m);
119   } else {
120     return (a_m >> fMin(b_e-a_e, FRACT_BITS-1) < b_m);
121   }
122 }
123 #endif
124 
125 
126 
127 #define LD_DATA_SCALING (64.0f)
128 #define LD_DATA_SHIFT   6   /* pow(2, LD_DATA_SHIFT) = LD_DATA_SCALING */
129 
130 /**
131  * \brief deprecated. Use fLog2() instead.
132  */
133 FIXP_DBL CalcLdData(FIXP_DBL op);
134 
135 void LdDataVector(FIXP_DBL *srcVector, FIXP_DBL *destVector, INT number);
136 
137 FIXP_DBL CalcInvLdData(FIXP_DBL op);
138 
139 
140 void     InitLdInt();
141 FIXP_DBL CalcLdInt(INT i);
142 
143 extern const USHORT sqrt_tab[49];
144 
sqrtFixp_lookup(FIXP_DBL x)145 inline FIXP_DBL sqrtFixp_lookup(FIXP_DBL x)
146 {
147   UINT y = (INT)x;
148   UCHAR is_zero=(y==0);
149   INT zeros=fixnormz_D(y) & 0x1e;
150   y<<=zeros;
151   UINT idx=(y>>26)-16;
152   USHORT frac=(y>>10)&0xffff;
153   USHORT nfrac=0xffff^frac;
154   UINT t=nfrac*sqrt_tab[idx]+frac*sqrt_tab[idx+1];
155   t=t>>(zeros>>1);
156   return(is_zero ? 0 : t);
157 }
158 
sqrtFixp_lookup(FIXP_DBL x,INT * x_e)159 inline FIXP_DBL sqrtFixp_lookup(FIXP_DBL x, INT *x_e)
160 {
161   UINT y = (INT)x;
162   INT e;
163 
164   if (x == (FIXP_DBL)0) {
165     return x;
166   }
167 
168   /* Normalize */
169   e=fixnormz_D(y);
170   y<<=e;
171   e  = *x_e - e + 2;
172 
173   /* Correct odd exponent. */
174   if (e & 1) {
175     y >>= 1;
176     e ++;
177   }
178   /* Get square root */
179   UINT idx=(y>>26)-16;
180   USHORT frac=(y>>10)&0xffff;
181   USHORT nfrac=0xffff^frac;
182   UINT t=nfrac*sqrt_tab[idx]+frac*sqrt_tab[idx+1];
183 
184   /* Write back exponent */
185   *x_e = e >> 1;
186   return (FIXP_DBL)(LONG)(t>>1);
187 }
188 
189 
190 
191 FIXP_DBL sqrtFixp(FIXP_DBL op);
192 
193 void InitInvSqrtTab();
194 
195 FIXP_DBL invSqrtNorm2(FIXP_DBL op, INT *shift);
196 
197 /*****************************************************************************
198 
199     functionname: invFixp
200     description:  delivers 1/(op)
201 
202 *****************************************************************************/
invFixp(FIXP_DBL op)203 inline FIXP_DBL invFixp(FIXP_DBL op)
204 {
205     INT tmp_exp ;
206     FIXP_DBL tmp_inv = invSqrtNorm2(op, &tmp_exp) ;
207     FDK_ASSERT((31-(2*tmp_exp+1))>=0) ;
208     return ( fPow2Div2( (FIXP_DBL)tmp_inv ) >> (31-(2*tmp_exp+1)) ) ;
209 }
210 
211 
212 
213 #if defined(__mips__) && (__GNUC__==2)
214 
215 #define FUNCTION_schur_div
schur_div(FIXP_DBL num,FIXP_DBL denum,INT count)216 inline FIXP_DBL schur_div(FIXP_DBL num,FIXP_DBL denum, INT count)
217 {
218   INT result, tmp ;
219    __asm__ ("srl %1, %2, 15\n"
220             "div %3, %1\n" : "=lo" (result)
221                            : "%d" (tmp), "d" (denum) ,  "d" (num)
222                            : "hi" ) ;
223   return result<<16 ;
224 }
225 
226 /*###########################################################################################*/
227 #elif defined(__mips__) && (__GNUC__==3)
228 
229 #define FUNCTION_schur_div
schur_div(FIXP_DBL num,FIXP_DBL denum,INT count)230 inline FIXP_DBL schur_div(FIXP_DBL num,FIXP_DBL denum, INT count)
231 {
232   INT result, tmp;
233 
234    __asm__ ("srl  %[tmp], %[denum], 15\n"
235             "div %[result], %[num], %[tmp]\n"
236             : [tmp] "+r" (tmp), [result]"=r"(result)
237             : [denum]"r"(denum), [num]"r"(num)
238             : "hi", "lo");
239   return result << (DFRACT_BITS-16);
240 }
241 
242 /*###########################################################################################*/
243 #elif defined(SIMULATE_MIPS_DIV)
244 
245 #define FUNCTION_schur_div
schur_div(FIXP_DBL num,FIXP_DBL denum,INT count)246 inline FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count)
247 {
248     FDK_ASSERT (count<=DFRACT_BITS-1);
249     FDK_ASSERT (num>=(FIXP_DBL)0);
250     FDK_ASSERT (denum>(FIXP_DBL)0);
251     FDK_ASSERT (num <= denum);
252 
253     INT tmp = denum >> (count-1);
254     INT result = 0;
255 
256     while (num > tmp)
257     {
258         num -= tmp;
259         result++;
260     }
261 
262     return result << (DFRACT_BITS-count);
263 }
264 
265 /*###########################################################################################*/
266 #endif /* target architecture selector */
267 
268 #if !defined(FUNCTION_schur_div)
269 /**
270  * \brief Divide two FIXP_DBL values with given precision.
271  * \param num dividend
272  * \param denum divisor
273  * \param count amount of significant bits of the result (starting to the MSB)
274  * \return num/divisor
275  */
276 FIXP_DBL schur_div(FIXP_DBL num,FIXP_DBL denum, INT count);
277 #endif
278 
279 
280 
281 FIXP_DBL mul_dbl_sgl_rnd (const FIXP_DBL op1,
282                           const FIXP_SGL op2);
283 
284 /**
285  * \brief multiply two values with normalization, thus max precision.
286  * Author: Robert Weidner
287  *
288  * \param f1 first factor
289  * \param f2 secod factor
290  * \param result_e pointer to an INT where the exponent of the result is stored into
291  * \return mantissa of the product f1*f2
292  */
293 FIXP_DBL fMultNorm(
294         FIXP_DBL f1,
295         FIXP_DBL f2,
296         INT *result_e
297         );
298 
fMultNorm(FIXP_DBL f1,FIXP_DBL f2)299 inline FIXP_DBL fMultNorm(FIXP_DBL f1, FIXP_DBL f2)
300 {
301   FIXP_DBL m;
302   INT e;
303 
304   m = fMultNorm(f1, f2, &e);
305 
306   m = scaleValueSaturate(m, e);
307 
308   return m;
309 }
310 
311 /**
312  * \brief Divide 2 FIXP_DBL values with normalization of input values.
313  * \param num numerator
314  * \param denum denomintator
315  * \return num/denum with exponent = 0
316  */
317 FIXP_DBL fDivNorm(FIXP_DBL num, FIXP_DBL denom, INT *result_e);
318 
319 /**
320  * \brief Divide 2 FIXP_DBL values with normalization of input values.
321  * \param num numerator
322  * \param denum denomintator
323  * \param result_e pointer to an INT where the exponent of the result is stored into
324  * \return num/denum with exponent = *result_e
325  */
326 FIXP_DBL fDivNorm(FIXP_DBL num, FIXP_DBL denom);
327 
328 /**
329  * \brief Divide 2 FIXP_DBL values with normalization of input values.
330  * \param num numerator
331  * \param denum denomintator
332  * \return num/denum with exponent = 0
333  */
334 FIXP_DBL fDivNormHighPrec(FIXP_DBL L_num, FIXP_DBL L_denum, INT *result_e);
335 
336 /**
337  * \brief Calculate log(argument)/log(2) (logarithm with base 2). deprecated. Use fLog2() instead.
338  * \param arg mantissa of the argument
339  * \param arg_e exponent of the argument
340  * \param result_e pointer to an INT to store the exponent of the result
341  * \return the mantissa of the result.
342  * \param
343  */
344 FIXP_DBL CalcLog2(FIXP_DBL arg, INT arg_e, INT *result_e);
345 
346 /**
347  * \brief return 2 ^ (exp * 2^exp_e)
348  * \param exp_m mantissa of the exponent to 2.0f
349  * \param exp_e exponent of the exponent to 2.0f
350  * \param result_e pointer to a INT where the exponent of the result will be stored into
351  * \return mantissa of the result
352  */
353 FIXP_DBL f2Pow(const FIXP_DBL exp_m, const INT exp_e, INT *result_e);
354 
355 /**
356  * \brief return 2 ^ (exp_m * 2^exp_e). This version returns only the mantissa with implicit exponent of zero.
357  * \param exp_m mantissa of the exponent to 2.0f
358  * \param exp_e exponent of the exponent to 2.0f
359  * \return mantissa of the result
360  */
361 FIXP_DBL f2Pow(const FIXP_DBL exp_m, const INT exp_e);
362 
363 /**
364  * \brief return x ^ (exp * 2^exp_e), where log2(x) = baseLd_m * 2^(baseLd_e). This saves
365  *        the need to compute log2() of constant values (when x is a constant).
366  * \param ldx_m mantissa of log2() of x.
367  * \param ldx_e exponent of log2() of x.
368  * \param exp_m mantissa of the exponent to 2.0f
369  * \param exp_e exponent of the exponent to 2.0f
370  * \param result_e pointer to a INT where the exponent of the result will be stored into
371  * \return mantissa of the result
372  */
373 FIXP_DBL fLdPow(
374         FIXP_DBL baseLd_m,
375         INT baseLd_e,
376         FIXP_DBL exp_m, INT exp_e,
377         INT *result_e
378         );
379 
380 /**
381  * \brief return x ^ (exp * 2^exp_e), where log2(x) = baseLd_m * 2^(baseLd_e). This saves
382  *        the need to compute log2() of constant values (when x is a constant). This version
383  *        does not return an exponent, which is implicitly 0.
384  * \param ldx_m mantissa of log2() of x.
385  * \param ldx_e exponent of log2() of x.
386  * \param exp_m mantissa of the exponent to 2.0f
387  * \param exp_e exponent of the exponent to 2.0f
388  * \return mantissa of the result
389  */
390 FIXP_DBL fLdPow(
391         FIXP_DBL baseLd_m, INT baseLd_e,
392         FIXP_DBL exp_m, INT exp_e
393         );
394 
395 /**
396  * \brief return (base * 2^base_e) ^ (exp * 2^exp_e). Use fLdPow() instead whenever possible.
397  * \param base_m mantissa of the base.
398  * \param base_e exponent of the base.
399  * \param exp_m mantissa of power to be calculated of the base.
400  * \param exp_e exponent of power to be calculated of the base.
401  * \param result_e pointer to a INT where the exponent of the result will be stored into.
402  * \return mantissa of the result.
403  */
404 FIXP_DBL fPow(FIXP_DBL base_m, INT base_e, FIXP_DBL exp_m, INT exp_e, INT *result_e);
405 
406 /**
407  * \brief return (base * 2^base_e) ^ N
408  * \param base mantissa of the base
409  * \param base_e exponent of the base
410  * \param power to be calculated of the base
411  * \param result_e pointer to a INT where the exponent of the result will be stored into
412  * \return mantissa of the result
413  */
414 FIXP_DBL fPowInt(FIXP_DBL base_m, INT base_e, INT N, INT *result_e);
415 
416 /**
417  * \brief calculate logarithm of base 2 of x_m * 2^(x_e)
418  * \param x_m mantissa of the input value.
419  * \param x_e exponent of the input value.
420  * \param pointer to an INT where the exponent of the result is returned into.
421  * \return mantissa of the result.
422  */
423 FIXP_DBL fLog2(FIXP_DBL x_m, INT x_e, INT *result_e);
424 
425 /**
426  * \brief calculate logarithm of base 2 of x_m * 2^(x_e)
427  * \param x_m mantissa of the input value.
428  * \param x_e exponent of the input value.
429  * \return mantissa of the result with implicit exponent of LD_DATA_SHIFT.
430  */
431 FIXP_DBL fLog2(FIXP_DBL x_m, INT x_e);
432 
433 /**
434  * \brief Add with saturation of the result.
435  * \param a first summand
436  * \param b second summand
437  * \return saturated sum of a and b.
438  */
fAddSaturate(const FIXP_SGL a,const FIXP_SGL b)439 inline FIXP_SGL fAddSaturate(const FIXP_SGL a, const FIXP_SGL b)
440 {
441   LONG sum;
442 
443   sum = (LONG)(SHORT)a + (LONG)(SHORT)b;
444   sum = fMax(fMin((INT)sum, (INT)MAXVAL_SGL), (INT)MINVAL_SGL);
445   return (FIXP_SGL)(SHORT)sum;
446 }
447 
448 /**
449  * \brief Add with saturation of the result.
450  * \param a first summand
451  * \param b second summand
452  * \return saturated sum of a and b.
453  */
fAddSaturate(const FIXP_DBL a,const FIXP_DBL b)454 inline FIXP_DBL fAddSaturate(const FIXP_DBL a, const FIXP_DBL b)
455 {
456   LONG sum;
457 
458   sum = (LONG)(a>>1) + (LONG)(b>>1);
459   sum = fMax(fMin((INT)sum, (INT)(MAXVAL_DBL>>1)), (INT)(MINVAL_DBL>>1));
460   return (FIXP_DBL)(LONG)(sum<<1);
461 }
462 
463 //#define TEST_ROUNDING
464 
465 
466 
467 
468 /*****************************************************************************
469 
470  array for 1/n, n=1..80
471 
472 ****************************************************************************/
473 
474   extern const FIXP_DBL invCount[80];
475 
476   LNK_SECTION_INITCODE
InitInvInt(void)477   inline void InitInvInt(void) {}
478 
479 
480 /**
481  * \brief Calculate the value of 1/i where i is a integer value. It supports
482  *        input values from 1 upto 80.
483  * \param intValue Integer input value.
484  * \param FIXP_DBL representation of 1/intValue
485  */
GetInvInt(int intValue)486 inline FIXP_DBL GetInvInt(int intValue)
487 {
488   FDK_ASSERT((intValue > 0) && (intValue < 80));
489   FDK_ASSERT(intValue<80);
490 	return invCount[intValue];
491 }
492 
493 
494 #endif
495 
496