Fraunhofer AAC codec.

License boilerplate update to follow.

Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5

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__ */