tran_det.h - Android社区 - https://www.androidos.net.cn/

/* -----------------------------------------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android

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

/*!
  \file
  \brief  Transient detector prototypes  
*/
#ifndef __TRAN_DET_H
#define __TRAN_DET_H

#include "sbr_encoder.h"
#include "sbr_def.h"

typedef struct
{
  FIXP_DBL  transients[QMF_MAX_TIME_SLOTS+(QMF_MAX_TIME_SLOTS/2)];
  FIXP_DBL  thresholds[QMF_CHANNELS];
  FIXP_DBL  tran_thr;              /* Master threshold for transient signals */
  FIXP_DBL  split_thr_m;           /* Threshold for splitting FIXFIX-frames into 2 env */
  INT       split_thr_e;           /* Scale for splitting threshold */
  FIXP_DBL  prevLowBandEnergy;     /* Energy of low band */
  FIXP_DBL  prevHighBandEnergy;    /* Energy of high band */
  INT    tran_fc;                  /* Number of lowband subbands to discard  */
  INT    no_cols;
  INT    no_rows;
  INT    mode;

int    frameShift;
  int    tran_off;                 /* Offset for reading energy values. */
}
SBR_TRANSIENT_DETECTOR;

typedef SBR_TRANSIENT_DETECTOR *HANDLE_SBR_TRANSIENT_DETECTOR;

#define TRAN_DET_LOOKAHEAD 2
#define TRAN_DET_START_FREQ 4500  /*start frequency for transient detection*/
#define TRAN_DET_STOP_FREQ  13500 /*stop frequency for transient detection*/
#define TRAN_DET_MIN_QMFBANDS 4 /* minimum qmf bands for transient detection */
#define QMF_HP_dBd_SLOPE_FIX FL2FXCONST_DBL(0.00075275f) /* 0.002266f/10 * log2(10) */
#define TRAN_DET_THRSHLD FL2FXCONST_DBL(3.2f/4.f)
#define TRAN_DET_THRSHLD_SCALE (2)

typedef struct
{
  INT transientCandidates[QMF_MAX_TIME_SLOTS + TRAN_DET_LOOKAHEAD];
  INT nTimeSlots;
  INT lookahead;
  INT startBand;
  INT stopBand;

FIXP_DBL dBf_m[QMF_CHANNELS];
  INT      dBf_e[QMF_CHANNELS];

FIXP_DBL energy_timeSlots[QMF_MAX_TIME_SLOTS + TRAN_DET_LOOKAHEAD];
  INT      energy_timeSlots_scale[QMF_MAX_TIME_SLOTS + TRAN_DET_LOOKAHEAD];

FIXP_DBL delta_energy[QMF_MAX_TIME_SLOTS + TRAN_DET_LOOKAHEAD];
  INT      delta_energy_scale[QMF_MAX_TIME_SLOTS + TRAN_DET_LOOKAHEAD];

FIXP_DBL lowpass_energy[QMF_MAX_TIME_SLOTS + TRAN_DET_LOOKAHEAD];
  INT      lowpass_energy_scale[QMF_MAX_TIME_SLOTS + TRAN_DET_LOOKAHEAD];
#if defined (FTD_LOG)
  FDKFILE *ftd_log;
#endif
}
FAST_TRAN_DETECTOR;
typedef FAST_TRAN_DETECTOR *HANDLE_FAST_TRAN_DET;

INT FDKsbrEnc_InitSbrFastTransientDetector(
        HANDLE_FAST_TRAN_DET h_sbrFastTransientDetector,
        const INT time_slots_per_frame,
        const INT bandwidth_qmf_slot,
        const INT no_qmf_channels,
        const INT sbr_qmf_1st_band
        );

void FDKsbrEnc_fastTransientDetect(
        const HANDLE_FAST_TRAN_DET          h_sbrFastTransientDetector,
        const FIXP_DBL              *const *Energies,
        const int                   *const  scaleEnergies,
        const INT                           YBufferWriteOffset,
              UCHAR                 *const  tran_vector
        );

void
FDKsbrEnc_transientDetect(HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTransientDetector,
                          FIXP_DBL **Energies,
                          INT *scaleEnergies,
                          UCHAR *tran_vector,
                          int YBufferWriteOffset,
                          int YBufferSzShift,
                          int timeStep,
                          int frameMiddleBorder);

int
FDKsbrEnc_InitSbrTransientDetector (HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTransientDetector,
                            UINT  sbrSyntaxFlags, /* SBR syntax flags derived from AOT. */
                            INT   frameSize,
                            INT   sampleFreq,
                            sbrConfigurationPtr params,
                            int   tran_fc,
                            int   no_cols,
                            int   no_rows,
                            int   YBufferWriteOffset,
                            int   YBufferSzShift,
                            int   frameShift,
                            int   tran_off);

void
FDKsbrEnc_frameSplitter(FIXP_DBL **Energies,
                        INT *scaleEnergies,
                        HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTransientDetector,
                        UCHAR *freqBandTable,
                        UCHAR *tran_vector,
                        int YBufferWriteOffset,
                        int YBufferSzShift,
                        int nSfb,
                        int timeStep,
                        int no_cols,
                        FIXP_DBL* tonality);
#endif

C++程序 | 204行 | 8.81 KB

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