android / platform / external / aac / ce97e7d55e1f69683b5bc8f19cc8da8c85bc2cd4 / . / libFDK / include / dct.h

/* ----------------------------------------------------------------------------- | |

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 | |

----------------------------------------------------------------------------- */ | |

/******************* Library for basic calculation routines ******************** | |

Author(s): | |

Description: Library functions to calculate standard DCTs. This will most | |

likely be replaced by hand-optimized functions for the specific | |

target processor. | |

*******************************************************************************/ | |

#ifndef DCT_H | |

#define DCT_H | |

#include "common_fix.h" | |

void dct_getTables(const FIXP_WTP **ptwiddle, const FIXP_STP **sin_twiddle, | |

int *sin_step, int length); | |

/** | |

* \brief Calculate DCT type II of given length. The DCT IV is | |

* calculated by a complex FFT, with some pre and post twiddeling. | |

* A factor of sqrt(2/(N-1)) is NOT applied. | |

* \param pDat pointer to input/output data (in place processing). | |

* \param size size of pDat. | |

* \param pDat_e pointer to an integer containing the exponent of the data | |

* referenced by pDat. The exponent is updated accordingly. | |

*/ | |

void dct_II(FIXP_DBL *pDat, FIXP_DBL *tmp, int size, int *pDat_e); | |

/** | |

* \brief Calculate DCT type III of given length. The DCT IV is | |

* calculated by a complex FFT, with some pre and post twiddeling. | |

* Note that the factor 0.5 for the sum term x[0] is 1.0 instead of 0.5. | |

* A factor of sqrt(2/N) is NOT applied. | |

* \param pDat pointer to input/output data (in place processing). | |

* \param size size of pDat. | |

* \param pDat_e pointer to an integer containing the exponent of the data | |

* referenced by pDat. The exponent is updated accordingly. | |

*/ | |

void dct_III(FIXP_DBL *pDat, FIXP_DBL *tmp, int size, int *pDat_e); | |

/** | |

* \brief Calculate DST type III of given length. The DST III is | |

* calculated by a DCT III of mirrored input and sign-flipping of odd | |

* output coefficients. | |

* Note that the factor 0.5 for the sum term x[N-1] is 1.0 instead of | |

* 0.5. A factor of sqrt(2/N) is NOT applied. | |

* \param pDat pointer to input/output data (in place processing). | |

* \param size size of pDat. | |

* \param pDat_e pointer to an integer containing the exponent of the data | |

* referenced by pDat. The exponent is updated accordingly. | |

*/ | |

void dst_III(FIXP_DBL *pDat, FIXP_DBL *tmp, int size, int *pDat_e); | |

/** | |

* \brief Calculate DCT type IV of given length. The DCT IV is | |

* calculated by a complex FFT, with some pre and post twiddeling. | |

* A factor of sqrt(2/N) is NOT applied. | |

* \param pDat pointer to input/output data (in place processing). | |

* \param size size of pDat. | |

* \param pDat_e pointer to an integer containing the exponent of the data | |

* referenced by pDat. The exponent is updated accordingly. | |

*/ | |

void dct_IV(FIXP_DBL *pDat, int size, int *pDat_e); | |

/** | |

* \brief Calculate DST type IV of given length. The DST IV is | |

* calculated by a complex FFT, with some pre and post twiddeling. | |

* A factor of sqrt(2/N) is NOT applied. | |

* \param pDat pointer to input/output data (in place processing). | |

* \param size size of pDat. | |

* \param pDat_e pointer to an integer containing the exponent of the data | |

* referenced by pDat. The exponent is updated accordingly. | |

*/ | |

void dst_IV(FIXP_DBL *pDat, int size, int *pDat_e); | |

#endif |