1
2/* -----------------------------------------------------------------------------------------------------------
3Software License for The Fraunhofer FDK AAC Codec Library for Android
4
5� Copyright  1995 - 2013 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#ifndef __RESAMPLER_H
85#define __RESAMPLER_H
86/*!
87  \file
88  \brief  Fixed Point Resampler Tool Box
89*/
90
91#include "common_fix.h"
92
93
94/**************************************************************************/
95/*                         BIQUAD Filter Structure                           */
96/**************************************************************************/
97
98#define MAXNR_SECTIONS  (15)
99
100#ifdef RS_BIQUAD_STATES16
101typedef FIXP_SGL FIXP_BQS;
102#else
103typedef FIXP_DBL FIXP_BQS;
104#endif
105
106typedef struct
107{
108  FIXP_BQS states[MAXNR_SECTIONS+1][2];   /*! state buffer */
109  const FIXP_SGL *coeffa;               /*! pointer to filter coeffs */
110  FIXP_DBL gain;                        /*! overall gain factor */
111  int Wc;                               /*! normalized cutoff freq * 1000 */
112  int noCoeffs;                         /*! number of filter coeffs sets */
113  int ptr;                              /*! index to rinbuffers */
114} LP_FILTER;
115
116
117/**************************************************************************/
118/*                        Downsampler Structure                           */
119/**************************************************************************/
120
121typedef struct
122{
123  LP_FILTER downFilter;           /*! filter instance */
124  int ratio;                      /*! downsampling ration */
125  int delay;                      /*! downsampling delay (source fs)   */
126  int pending;                    /*! number of pending output samples */
127} DOWNSAMPLER;
128
129
130/**
131 * \brief Initialized a given downsampler structure.
132 */
133INT FDKaacEnc_InitDownsampler(DOWNSAMPLER *DownSampler, /*!< pointer to downsampler instance */
134                              INT Wc,                   /*!< normalized cutoff freq * 1000 */
135                              INT ratio);               /*!< downsampler ratio */
136
137/**
138 * \brief Downsample a set of audio samples. numInSamples must be at least equal to the
139 *        downsampler ratio.
140 */
141INT FDKaacEnc_Downsample(DOWNSAMPLER *DownSampler,  /*!< pointer to downsampler instance */
142                         INT_PCM *inSamples,        /*!< pointer to input samples */
143                         INT numInSamples,          /*!< number  of input samples  */
144                         INT inStride,              /*!< increment of input samples      */
145                         INT_PCM *outSamples,       /*!< pointer to output samples */
146                         INT *numOutSamples,        /*!< pointer tp number of output samples */
147                         INT outstride);            /*!< increment of output samples */
148
149
150
151#endif /* __RESAMPLER_H */
152