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Diffstat (limited to 'libFDK/include/mdct.h')
| -rw-r--r-- | libFDK/include/mdct.h | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/libFDK/include/mdct.h b/libFDK/include/mdct.h new file mode 100644 index 0000000..f96ea06 --- /dev/null +++ b/libFDK/include/mdct.h @@ -0,0 +1,181 @@ +/*************************** Fraunhofer IIS FDK Tools ********************** + + (C) Copyright Fraunhofer IIS (2011) + All Rights Reserved + + Please be advised that this software and/or program delivery is + Confidential Information of Fraunhofer and subject to and covered by the + + Fraunhofer IIS Software Evaluation Agreement + between Google Inc. and Fraunhofer + effective and in full force since March 1, 2012. + + You may use this software and/or program only under the terms and + conditions described in the above mentioned Fraunhofer IIS Software + Evaluation Agreement. Any other and/or further use requires a separate agreement. + + + $Id$ + Author(s): Manuel Jander, Josef Hoepfl + Description: MDCT routines + + This software and/or program is protected by copyright law and international + treaties. Any reproduction or distribution of this software and/or program, + or any portion of it, may result in severe civil and criminal penalties, and + will be prosecuted to the maximum extent possible under law. + +******************************************************************************/ + +#ifndef __MDCT_H__ +#define __MDCT_H__ + + + +#include "common_fix.h" + +#define MDCT_OUT_HEADROOM 2 /* Output additional headroom */ +#define MDCT_OUTPUT_SCALE (DFRACT_BITS-SAMPLE_BITS-MDCT_OUT_HEADROOM) +/* Refer to "Output word length" in ISO/IEC 14496-3:2008(E) 23.2.3.6 */ +#define MDCT_OUTPUT_GAIN 16 + +#if (SAMPLE_BITS == DFRACT_BITS) +#define IMDCT_SCALE(x) (INT_PCM)SATURATE_LEFT_SHIFT(x, -MDCT_OUTPUT_SCALE, SAMPLE_BITS) +#else +#define IMDCT_SCALE(x) (INT_PCM)SATURATE_RIGHT_SHIFT(x, MDCT_OUTPUT_SCALE, SAMPLE_BITS) +#endif +#define IMDCT_SCALE_DBL(x) (FIXP_DBL)(x) + +/** + * \brief MDCT persistent data + */ +typedef struct { + union { + FIXP_DBL *freq; + FIXP_DBL *time; + } overlap; /**< Pointer to overlap memory */ + + const FIXP_WTP *prev_wrs; /**< pointer to previous right window slope */ + int prev_tl; /**< previous tranform length */ + int prev_nr; /**< previous right window offset */ + int prev_fr; /**< previous right window slope length */ + int ov_offset; /**< overlap time data fill level */ + int ov_size; /**< Overlap buffer size in words */ + +} mdct_t; + +typedef mdct_t* H_MDCT; + +/** + * \brief Initialize as valid MDCT handle + * + * \param hMdct handle of an allocated MDCT handle. + * \param overlap pointer to FIXP_DBL overlap buffer. + * \param overlapBufferSize size in FIXP_DBLs of the given overlap buffer. + * \return void + */ +void mdct_init( H_MDCT hMdct, + FIXP_DBL *overlap, + INT overlapBufferSize ); + +/** + * \brief perform MDCT transform (time domain to frequency domain) with given parameters. + * + * \param hMdct handle of an allocated MDCT handle. + * \param spectrum pointer to where the resulting MDCT spectrum will be stored into. + * \param scalefactor pointer to the input scale shift value. Updated accordingly on return. + * \param input pointer to input time domain signal + * \param tl transformation length. + * \param nr right window slope offset (amount of window coefficients assumed to be 1.0) + * \param fr right overlap window slope length + * \param wrs pointer to the right side overlap window coefficients. + * \return number of input samples processed. + */ +INT mdct_block( + H_MDCT hMdct, + FIXP_DBL *spectrum, + INT *scalefactor, + INT_PCM *input, + INT tl, + INT nr, + INT fr, + const FIXP_WTB *wrs ); + + +/** + * \brief add/multiply 2/N transform gain and MPEG4 part 3 defined output gain (see definition + * of MDCT_OUTPUT_GAIN) to given mantissa factor and exponent. + * \param pGain pointer to the mantissa of a gain factor to be applied to IMDCT data. + * \param pExponent pointer to the exponent of a gain factor to be applied to IMDCT data. + * \param tl length of the IMDCT where the gain *pGain * (2 ^ *pExponent) will be applied to. + */ +void imdct_gain( + FIXP_DBL *pGain, + int *pExponent, + int tl + ); + +/** + * \brief drain buffered output samples into given buffer. Changes the MDCT state. + */ +INT imdct_drain( + H_MDCT hMdct, + FIXP_DBL * pTimeData, + INT nrSamplesRoom + ); + + +/** + * \brief Copy overlap time domain data to given buffer. Does not change the MDCT state. + * \return number of actually copied samples (ov + nr). + */ +INT imdct_copy_ov_and_nr( + H_MDCT hMdct, + FIXP_DBL * pTimeData, + INT nrSamples + ); + +/** + * \brief Adapt MDCT parameters for non-matching window slopes. + * \param hMdct handle of an allocated MDCT handle. + * \param pfl pointer to left overlap window side length. + * \param pnl pointer to length of the left n part of the window. + * \param tl transform length. + * \param wls pointer to the left side overlap window coefficients. + * \param noOutSamples desired number of output samples. + */ +void imdct_adapt_parameters(H_MDCT hMdct, int *pfl, int *pnl, int tl, const FIXP_WTP *wls, int noOutSamples); + +/** + * \brief perform several inverse MDCT transforms (frequency domain to time domain) with given parameters. + * + * \param hMdct handle of an allocated MDCT handle. + * \param output pointer to where the output time domain signal will be stored into. + * \param stride the stride factor for accessing time domain samples in output. + * \param spectrum pointer to the input MDCT spectra. + * \param scalefactors scale shift values of the input spectrum. + * \param nSpec number of MDCT spectrums. + * \param noOutSamples desired number of output samples. + * \param tl transform length. + * \param wls pointer to the left side overlap window coefficients. + * \param fl left overlap window side length. + * \param wrs pointer to the right side overlap window coefficients of all individual IMDCTs. + * \param fr right overlap window side length of all individual IMDCTs. + * \param gain factor to apply to output samples (if != 0). + * \return number of output samples returned. + */ +INT imdct_block( + H_MDCT hMdct, + FIXP_DBL *output, + FIXP_DBL *spectrum, + const SHORT scalefactor[], + const INT nSpec, + const INT noOutSamples, + const INT tl, + const FIXP_WTP *wls, + INT fl, + const FIXP_WTP *wrs, + const INT fr, + FIXP_DBL gain ); + + +#endif /* __MDCT_H__ */ |