libAACdec/src/stereo.h - third_party/android/platform/external/aac - Git at Google

 /* -----------------------------------------------------------------------------
 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
 ----------------------------------------------------------------------------- */

 /**************************** AAC decoder library ******************************

    Author(s):   Josef Hoepfl

    Description: joint stereo processing

 *******************************************************************************/

 #ifndef STEREO_H
 #define STEREO_H

 #include "machine_type.h"
 #include "FDK_bitstream.h"
 #include "common_fix.h"

 #define SFB_PER_PRED_BAND 2

 #define SR_FNA_OUT                                                           \
   0 /* Additional scaling of the CJointStereo_filterAndAdd()-output to avoid \
        overflows.    */
     /* The scaling factor can be set to 0 if the coefficients are prescaled
      * appropriately. */
 /* Prescaling via factor SF_FNA_COEFFS is done at compile-time but should only
  * be      */
 /* utilized if the coefficients are stored as FIXP_DBL. (cp. aac_rom.cpp/.h) */

 /* The NO_CPLX_PRED_BUGFIX-switch was introduced to enable decoding of
    conformance-streams in way that they are comparable to buggy
    reference-streams. This is established by storing the prediction direction
    for computation of the "downmix MDCT of previous frame". This is not standard
    compliant. Once correct reference-streams for complex-stereo-prediction are
    available this switch becomes obsolete.
 */
 /*#define NO_CPLX_PRED_BUGFIX*/

 enum { JointStereoMaximumGroups = 8, JointStereoMaximumBands = 64 };

 typedef struct {
   UCHAR pred_dir;  // 0 = prediction from mid to side channel, 1 = vice versa
   UCHAR
   igf_pred_dir;  // 0 = prediction from mid to side channel, 1 = vice versa
   UCHAR complex_coef;    // 0 = alpha_q_im[x] is 0 for all prediction bands, 1 =
                          // alpha_q_im[x] is transmitted via bitstream
   UCHAR use_prev_frame;  // 0 = use current frame for MDST estimation, 1 = use
                          // current and previous frame

   SHORT alpha_q_re[JointStereoMaximumGroups][JointStereoMaximumBands];
   SHORT alpha_q_im[JointStereoMaximumGroups][JointStereoMaximumBands];
 } CCplxPredictionData;

 /* joint stereo scratch memory (valid for this frame) */
 typedef struct {
   UCHAR MsMaskPresent;
   UCHAR MsUsed[JointStereoMaximumBands]; /*!< every arry element contains flags
                                             for up to 8 groups. this array is
                                             also utilized for complex stereo
                                             prediction. */
   UCHAR IGF_MsMaskPresent;

   UCHAR cplx_pred_flag; /* stereo complex prediction was signalled for this
                            frame */
   UCHAR igf_cplx_pred_flag;

   /* The following array and variable are needed for the case  when INF is
    * active */
   FIXP_DBL store_dmx_re_prev[1024];
   SHORT store_dmx_re_prev_e;

 } CJointStereoData;

 /* joint stereo persistent memory */
 typedef struct {
   UCHAR clearSpectralCoeffs; /* indicates that the spectral coeffs must be
                                 cleared because the transform splitting active
                                 flag of the left and right channel was different
                               */

   FIXP_DBL *scratchBuffer; /* pointer to scratch buffer */

   FIXP_DBL
   *spectralCoeffs[2]; /* spectral coefficients of this channel utilized by
                          complex stereo prediction */
   SHORT *specScale[2];

   SHORT alpha_q_re_prev[JointStereoMaximumGroups][JointStereoMaximumBands];
   SHORT alpha_q_im_prev[JointStereoMaximumGroups][JointStereoMaximumBands];

   UCHAR winSeqPrev;
   UCHAR winShapePrev;
   UCHAR winGroupsPrev;

 } CJointStereoPersistentData;

 /*!
   \brief Read joint stereo data from bitstream

   The function reads joint stereo data from bitstream.

   \param bs bit stream handle data source.
   \param pJointStereoData pointer to stereo data structure to receive decoded
   data. \param windowGroups number of window groups. \param
   scaleFactorBandsTransmitted number of transmitted scalefactor bands. \param
   flags decoder flags

   \return  0 on success, -1 on error.
 */
 int CJointStereo_Read(HANDLE_FDK_BITSTREAM bs,
                       CJointStereoData *pJointStereoData,
                       const int windowGroups,
                       const int scaleFactorBandsTransmitted,
                       const int max_sfb_ste_clear,
                       CJointStereoPersistentData *pJointStereoPersistentData,
                       CCplxPredictionData *cplxPredictionData,
                       int cplxPredictionActiv, int scaleFactorBandsTotal,
                       int windowSequence, const UINT flags);

 #endif /* #ifndef STEREO_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
	----------------------------------------------------------------------------- */

	/************************** AAC decoder library ****************************

	Author(s): Josef Hoepfl

	Description: joint stereo processing

	*******************************************************************************/

	#ifndef STEREO_H
	#define STEREO_H

	#include "machine_type.h"
	#include "FDK_bitstream.h"
	#include "common_fix.h"

	#define SFB_PER_PRED_BAND 2

	#define SR_FNA_OUT \
	0 /* Additional scaling of the CJointStereo_filterAndAdd()-output to avoid \
	overflows. */
	/* The scaling factor can be set to 0 if the coefficients are prescaled
	* appropriately. */
	/* Prescaling via factor SF_FNA_COEFFS is done at compile-time but should only
	* be */
	/* utilized if the coefficients are stored as FIXP_DBL. (cp. aac_rom.cpp/.h) */

	/* The NO_CPLX_PRED_BUGFIX-switch was introduced to enable decoding of
	conformance-streams in way that they are comparable to buggy
	reference-streams. This is established by storing the prediction direction
	for computation of the "downmix MDCT of previous frame". This is not standard
	compliant. Once correct reference-streams for complex-stereo-prediction are
	available this switch becomes obsolete.
	*/
	/#define NO_CPLX_PRED_BUGFIX/

	enum { JointStereoMaximumGroups = 8, JointStereoMaximumBands = 64 };

	typedef struct {
	UCHAR pred_dir; // 0 = prediction from mid to side channel, 1 = vice versa
	UCHAR
	igf_pred_dir; // 0 = prediction from mid to side channel, 1 = vice versa
	UCHAR complex_coef; // 0 = alpha_q_im[x] is 0 for all prediction bands, 1 =
	// alpha_q_im[x] is transmitted via bitstream
	UCHAR use_prev_frame; // 0 = use current frame for MDST estimation, 1 = use
	// current and previous frame

	SHORT alpha_q_re[JointStereoMaximumGroups][JointStereoMaximumBands];
	SHORT alpha_q_im[JointStereoMaximumGroups][JointStereoMaximumBands];
	} CCplxPredictionData;

	/* joint stereo scratch memory (valid for this frame) */
	typedef struct {
	UCHAR MsMaskPresent;
	UCHAR MsUsed[JointStereoMaximumBands]; /*!< every arry element contains flags
	for up to 8 groups. this array is
	also utilized for complex stereo
	prediction. */
	UCHAR IGF_MsMaskPresent;

	UCHAR cplx_pred_flag; /* stereo complex prediction was signalled for this
	frame */
	UCHAR igf_cplx_pred_flag;

	/* The following array and variable are needed for the case when INF is
	* active */
	FIXP_DBL store_dmx_re_prev[1024];
	SHORT store_dmx_re_prev_e;

	} CJointStereoData;

	/* joint stereo persistent memory */
	typedef struct {
	UCHAR clearSpectralCoeffs; /* indicates that the spectral coeffs must be
	cleared because the transform splitting active
	flag of the left and right channel was different
	*/

	FIXP_DBL scratchBuffer; / pointer to scratch buffer */

	FIXP_DBL
	spectralCoeffs[2]; / spectral coefficients of this channel utilized by
	complex stereo prediction */
	SHORT *specScale[2];

	SHORT alpha_q_re_prev[JointStereoMaximumGroups][JointStereoMaximumBands];
	SHORT alpha_q_im_prev[JointStereoMaximumGroups][JointStereoMaximumBands];

	UCHAR winSeqPrev;
	UCHAR winShapePrev;
	UCHAR winGroupsPrev;

	} CJointStereoPersistentData;

	/*!
	\brief Read joint stereo data from bitstream

	The function reads joint stereo data from bitstream.

	\param bs bit stream handle data source.
	\param pJointStereoData pointer to stereo data structure to receive decoded
	data. \param windowGroups number of window groups. \param
	scaleFactorBandsTransmitted number of transmitted scalefactor bands. \param
	flags decoder flags

	\return 0 on success, -1 on error.
	*/
	int CJointStereo_Read(HANDLE_FDK_BITSTREAM bs,
	CJointStereoData *pJointStereoData,
	const int windowGroups,
	const int scaleFactorBandsTransmitted,
	const int max_sfb_ste_clear,
	CJointStereoPersistentData *pJointStereoPersistentData,
	CCplxPredictionData *cplxPredictionData,
	int cplxPredictionActiv, int scaleFactorBandsTotal,
	int windowSequence, const UINT flags);

	#endif /* #ifndef STEREO_H */