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authorThe Android Open Source Project <initial-contribution@android.com>2012-07-11 10:15:24 -0700
committerThe Android Open Source Project <initial-contribution@android.com>2012-07-11 10:15:24 -0700
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+
+/* -----------------------------------------------------------------------------------------------------------
+Software License for The Fraunhofer FDK AAC Codec Library for Android
+
+© Copyright 1995 - 2012 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
+----------------------------------------------------------------------------------------------------------- */
+
+/*************************** Fraunhofer IIS FDK Tools **********************
+
+ Author(s): Manuel Jander, Josef Hoepfl
+ Description: MDCT routines
+
+******************************************************************************/
+
+#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__ */