1 /* -----------------------------------------------------------------------------
2 Software License for The Fraunhofer FDK AAC Codec Library for Android
3 
4 © Copyright  1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
5 Forschung e.V. All rights reserved.
6 
7  1.    INTRODUCTION
8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
10 scheme for digital audio. This FDK AAC Codec software is intended to be used on
11 a wide variety of Android devices.
12 
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
14 general perceptual audio codecs. AAC-ELD is considered the best-performing
15 full-bandwidth communications codec by independent studies and is widely
16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG
17 specifications.
18 
19 Patent licenses for necessary patent claims for the FDK AAC Codec (including
20 those of Fraunhofer) may be obtained through Via Licensing
21 (www.vialicensing.com) or through the respective patent owners individually for
22 the purpose of encoding or decoding bit streams in products that are compliant
23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
24 Android devices already license these patent claims through Via Licensing or
25 directly from the patent owners, and therefore FDK AAC Codec software may
26 already be covered under those patent licenses when it is used for those
27 licensed purposes only.
28 
29 Commercially-licensed AAC software libraries, including floating-point versions
30 with enhanced sound quality, are also available from Fraunhofer. Users are
31 encouraged to check the Fraunhofer website for additional applications
32 information and documentation.
33 
34 2.    COPYRIGHT LICENSE
35 
36 Redistribution and use in source and binary forms, with or without modification,
37 are permitted without payment of copyright license fees provided that you
38 satisfy the following conditions:
39 
40 You must retain the complete text of this software license in redistributions of
41 the FDK AAC Codec or your modifications thereto in source code form.
42 
43 You must retain the complete text of this software license in the documentation
44 and/or other materials provided with redistributions of the FDK AAC Codec or
45 your modifications thereto in binary form. You must make available free of
46 charge copies of the complete source code of the FDK AAC Codec and your
47 modifications thereto to recipients of copies in binary form.
48 
49 The name of Fraunhofer may not be used to endorse or promote products derived
50 from this library without prior written permission.
51 
52 You may not charge copyright license fees for anyone to use, copy or distribute
53 the FDK AAC Codec software or your modifications thereto.
54 
55 Your modified versions of the FDK AAC Codec must carry prominent notices stating
56 that you changed the software and the date of any change. For modified versions
57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
59 AAC Codec Library for Android."
60 
61 3.    NO PATENT LICENSE
62 
63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
65 Fraunhofer provides no warranty of patent non-infringement with respect to this
66 software.
67 
68 You may use this FDK AAC Codec software or modifications thereto only for
69 purposes that are authorized by appropriate patent licenses.
70 
71 4.    DISCLAIMER
72 
73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
75 including but not limited to the implied warranties of merchantability and
76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
78 or consequential damages, including but not limited to procurement of substitute
79 goods or services; loss of use, data, or profits, or business interruption,
80 however caused and on any theory of liability, whether in contract, strict
81 liability, or tort (including negligence), arising in any way out of the use of
82 this software, even if advised of the possibility of such damage.
83 
84 5.    CONTACT INFORMATION
85 
86 Fraunhofer Institute for Integrated Circuits IIS
87 Attention: Audio and Multimedia Departments - FDK AAC LL
88 Am Wolfsmantel 33
89 91058 Erlangen, Germany
90 
91 www.iis.fraunhofer.de/amm
92 amm-info@iis.fraunhofer.de
93 ----------------------------------------------------------------------------- */
94 
95 /**************************** SBR encoder library ******************************
96 
97    Author(s):
98 
99    Description:
100 
101 *******************************************************************************/
102 
103 /*!
104   \file
105   \brief  Transient detector prototypes $Revision: 95111 $
106 */
107 #ifndef TRAN_DET_H
108 #define TRAN_DET_H
109 
110 #include "sbr_encoder.h"
111 #include "sbr_def.h"
112 
113 typedef struct {
114   FIXP_DBL transients[32 + (32 / 2)];
115   FIXP_DBL thresholds[64];
116   FIXP_DBL tran_thr;    /* Master threshold for transient signals */
117   FIXP_DBL split_thr_m; /* Threshold for splitting FIXFIX-frames into 2 env */
118   INT split_thr_e;      /* Scale for splitting threshold */
119   FIXP_DBL prevLowBandEnergy;  /* Energy of low band */
120   FIXP_DBL prevHighBandEnergy; /* Energy of high band */
121   INT tran_fc;                 /* Number of lowband subbands to discard  */
122   INT no_cols;
123   INT no_rows;
124   INT mode;
125 
126   int frameShift;
127   int tran_off; /* Offset for reading energy values. */
128 } SBR_TRANSIENT_DETECTOR;
129 
130 typedef SBR_TRANSIENT_DETECTOR *HANDLE_SBR_TRANSIENT_DETECTOR;
131 
132 #define TRAN_DET_LOOKAHEAD 2
133 #define TRAN_DET_START_FREQ 4500 /*start frequency for transient detection*/
134 #define TRAN_DET_STOP_FREQ 13500 /*stop frequency for transient detection*/
135 #define TRAN_DET_MIN_QMFBANDS                    \
136   4 /* minimum qmf bands for transient detection \
137      */
138 #define QMF_HP_dBd_SLOPE_FIX \
139   FL2FXCONST_DBL(0.00075275f) /* 0.002266f/10 * log2(10) */
140 #define TRAN_DET_THRSHLD FL2FXCONST_DBL(5.0f / 8.0f)
141 #define TRAN_DET_THRSHLD_SCALE (3)
142 
143 typedef struct {
144   INT transientCandidates[32 + TRAN_DET_LOOKAHEAD];
145   INT nTimeSlots;
146   INT lookahead;
147   INT startBand;
148   INT stopBand;
149 
150   FIXP_DBL dBf_m[64];
151   INT dBf_e[64];
152 
153   FIXP_DBL energy_timeSlots[32 + TRAN_DET_LOOKAHEAD];
154   INT energy_timeSlots_scale[32 + TRAN_DET_LOOKAHEAD];
155 
156   FIXP_DBL delta_energy[32 + TRAN_DET_LOOKAHEAD];
157   INT delta_energy_scale[32 + TRAN_DET_LOOKAHEAD];
158 
159   FIXP_DBL lowpass_energy[32 + TRAN_DET_LOOKAHEAD];
160   INT lowpass_energy_scale[32 + TRAN_DET_LOOKAHEAD];
161 } FAST_TRAN_DETECTOR;
162 typedef FAST_TRAN_DETECTOR *HANDLE_FAST_TRAN_DET;
163 
164 INT FDKsbrEnc_InitSbrFastTransientDetector(
165     HANDLE_FAST_TRAN_DET h_sbrFastTransientDetector,
166     const INT time_slots_per_frame, const INT bandwidth_qmf_slot,
167     const INT no_qmf_channels, const INT sbr_qmf_1st_band);
168 
169 void FDKsbrEnc_fastTransientDetect(
170     const HANDLE_FAST_TRAN_DET h_sbrFastTransientDetector,
171     const FIXP_DBL *const *Energies, const int *const scaleEnergies,
172     const INT YBufferWriteOffset, UCHAR *const tran_vector);
173 
174 void FDKsbrEnc_transientDetect(
175     HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTransientDetector, FIXP_DBL **Energies,
176     INT *scaleEnergies, UCHAR *tran_vector, int YBufferWriteOffset,
177     int YBufferSzShift, int timeStep, int frameMiddleBorder);
178 
179 int FDKsbrEnc_InitSbrTransientDetector(
180     HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTransientDetector,
181     UINT sbrSyntaxFlags, /* SBR syntax flags derived from AOT. */
182     INT frameSize, INT sampleFreq, sbrConfigurationPtr params, int tran_fc,
183     int no_cols, int no_rows, int YBufferWriteOffset, int YBufferSzShift,
184     int frameShift, int tran_off);
185 
186 void FDKsbrEnc_frameSplitter(
187     FIXP_DBL **Energies, INT *scaleEnergies,
188     HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTransientDetector, UCHAR *freqBandTable,
189     UCHAR *tran_vector, int YBufferWriteOffset, int YBufferSzShift, int nSfb,
190     int timeStep, int no_cols, FIXP_DBL *tonality);
191 #endif
192