Snapshot 2bda038c163298531d47394bc2c09e1409c5d0db

Change-Id: If584e579464f28b97d50e51fc76ba654a5536c54

1 files changed, 385 insertions, 0 deletions

diff --git a/libFDK/src/mdct.cpp b/libFDK/src/mdct.cpp
new file mode 100644
index 0000000..7b9864f
--- /dev/null
+++ b/libFDK/src/mdct.cpp
@@ -0,0 +1,385 @@
+
+/* -----------------------------------------------------------------------------------------------------------
+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):   Josef Hoepfl, Manuel Jander
+   Description: MDCT routines
+
+******************************************************************************/
+
+#include "mdct.h"
+
+
+#include "FDK_tools_rom.h"
+#include "dct.h"
+#include "fixpoint_math.h"
+
+
+void mdct_init( H_MDCT hMdct,
+                FIXP_DBL *overlap,
+                INT overlapBufferSize )
+{
+  hMdct->overlap.freq = overlap;
+  //FDKmemclear(overlap, overlapBufferSize*sizeof(FIXP_DBL));
+  hMdct->prev_fr = 0;
+  hMdct->prev_nr = 0;
+  hMdct->prev_tl = 0;
+  hMdct->ov_size = overlapBufferSize;
+}
+
+
+void imdct_gain(FIXP_DBL *pGain_m, int *pGain_e, int tl)
+{
+  FIXP_DBL gain_m = *pGain_m;
+  int gain_e = *pGain_e;
+  int log2_tl;
+
+  log2_tl = DFRACT_BITS-1-fNormz((FIXP_DBL)tl);
+
+  gain_e += -MDCT_OUTPUT_GAIN - log2_tl - MDCT_OUT_HEADROOM + 1;
+
+  /* Detect non-radix 2 transform length and add amplitude compensation factor
+     which cannot be included into the exponent above */
+  switch ( (tl) >> (log2_tl - 2) ) {
+    case 0x7: /* 10 ms, 1/tl = 1.0/(FDKpow(2.0, -log2_tl) * 0.53333333333333333333) */
+      if (gain_m == (FIXP_DBL)0) {
+        gain_m = FL2FXCONST_DBL(0.53333333333333333333f);
+      } else {
+        gain_m = fMult(gain_m, FL2FXCONST_DBL(0.53333333333333333333f));
+      }
+      break;
+    case 0x6: /* 3/4 of radix 2, 1/tl = 1.0/(FDKpow(2.0, -log2_tl) * 2.0/3.0) */
+      if (gain_m == (FIXP_DBL)0) {
+        gain_m = FL2FXCONST_DBL(2.0/3.0f);
+      } else {
+        gain_m = fMult(gain_m, FL2FXCONST_DBL(2.0/3.0f));
+      }
+      break;
+    case 0x4:
+      /* radix 2, nothing to do. */
+      break;
+    default:
+      /* unsupported */
+      FDK_ASSERT(0);
+      break;
+  }
+
+  *pGain_m = gain_m;
+  *pGain_e = gain_e;
+}
+
+INT imdct_drain(
+        H_MDCT hMdct,
+        FIXP_DBL *output,
+        INT nrSamplesRoom
+        )
+{
+  int buffered_samples = 0;
+
+  if (nrSamplesRoom > 0) {
+    buffered_samples = hMdct->ov_offset;
+
+    FDK_ASSERT(buffered_samples <= nrSamplesRoom);
+
+    if (buffered_samples > 0)  {
+      FDKmemcpy(output, hMdct->overlap.time, buffered_samples*sizeof(FIXP_DBL));
+      hMdct->ov_offset = 0;
+    }
+  }
+  return buffered_samples;
+}
+
+INT imdct_copy_ov_and_nr(
+        H_MDCT hMdct,
+        FIXP_DBL * pTimeData,
+        INT nrSamples
+        )
+{
+  FIXP_DBL *pOvl;
+  int nt, nf, i;
+
+  nt = fMin(hMdct->ov_offset, nrSamples);
+  nrSamples -= nt;
+  nf = fMin(hMdct->prev_nr, nrSamples);
+  nrSamples -= nf;
+  FDKmemcpy(pTimeData, hMdct->overlap.time, nt*sizeof(FIXP_DBL));
+  pTimeData += nt;
+
+  pOvl = hMdct->overlap.freq + hMdct->ov_size - 1;
+  for (i=0; i<nf; i++) {
+    FIXP_DBL x = - (*pOvl--);
+    *pTimeData = IMDCT_SCALE_DBL(x);
+    pTimeData ++;
+  }
+
+  return (nt+nf);
+}
+
+void imdct_adapt_parameters(H_MDCT hMdct, int *pfl, int *pnl, int tl, const FIXP_WTP *wls, int noOutSamples)
+{
+  int fl = *pfl, nl = *pnl;
+  int window_diff, use_current = 0, use_previous = 0;
+  if (hMdct->prev_tl == 0) {
+    hMdct->prev_wrs    = wls;
+    hMdct->prev_fr     = fl;
+    hMdct->prev_nr     = (noOutSamples-fl)>>1;
+    hMdct->prev_tl     = noOutSamples;
+    hMdct->ov_offset   = 0;
+    use_current = 1;
+  }
+
+  window_diff = (hMdct->prev_fr - fl)>>1;
+
+  /* check if the previous window slope can be adjusted to match the current window slope */
+  if (hMdct->prev_nr + window_diff > 0) {
+    use_current = 1;
+  }
+  /* check if the current window slope can be adjusted to match the previous window slope */
+  if (nl - window_diff > 0 ) {
+    use_previous = 1;
+  }
+
+  /* if both is possible choose the larger of both window slope lengths */
+  if (use_current && use_previous) {
+    if (fl < hMdct->prev_fr) {
+      use_current = 0;
+    } else {
+      use_previous = 0;
+    }
+  }
+  /*
+   * If the previous transform block is big enough, enlarge previous window overlap,
+   * if not, then shrink current window overlap.
+   */
+  if (use_current) {
+    hMdct->prev_nr += window_diff;
+    hMdct->prev_fr = fl;
+    hMdct->prev_wrs = wls;
+  } else {
+    nl -= window_diff;
+    fl = hMdct->prev_fr;
+  }
+
+  *pfl = fl;
+  *pnl = nl;
+}
+
+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
+        )
+{
+  FIXP_DBL *pOvl;
+  FIXP_DBL *pOut0 = output, *pOut1;
+  INT nl, nr;
+  int w, i, nrSamples = 0, specShiftScale, transform_gain_e = 0;
+
+  /* Derive NR and NL */
+  nr = (tl - fr)>>1;
+  nl = (tl - fl)>>1;
+
+  /* Include 2/N IMDCT gain into gain factor and exponent. */
+  imdct_gain(&gain, &transform_gain_e, tl);
+
+  /* Detect FRprevious / FL mismatches and override parameters accordingly */
+  if (hMdct->prev_fr != fl) {
+    imdct_adapt_parameters(hMdct, &fl, &nl, tl, wls, noOutSamples);
+  }
+
+  pOvl = hMdct->overlap.freq + hMdct->ov_size - 1;
+
+  if ( noOutSamples > nrSamples ) {
+    /* Purge buffered output. */
+    for (i=0; i<hMdct->ov_offset; i++) {
+      *pOut0 = hMdct->overlap.time[i];
+      pOut0 ++;
+    }
+    nrSamples = hMdct->ov_offset;
+    hMdct->ov_offset = 0;
+  }
+
+  for (w=0; w<nSpec; w++)
+  {
+    FIXP_DBL *pSpec, *pCurr;
+    const FIXP_WTP *pWindow;
+
+    specShiftScale = transform_gain_e;
+
+    /* Setup window pointers */
+    pWindow = hMdct->prev_wrs;
+
+    /* Current spectrum */
+    pSpec = spectrum+w*tl;
+
+    /* DCT IV of current spectrum. */
+    dct_IV(pSpec, tl, &specShiftScale);
+
+    /* Optional scaling of time domain - no yet windowed - of current spectrum */
+    /* and de-scale current spectrum signal (time domain, no yet windowed) */	
+    if (gain != (FIXP_DBL)0) {
+      scaleValuesWithFactor(pSpec, gain, tl, scalefactor[w] + specShiftScale);
+    } else {
+      scaleValues(pSpec, tl, scalefactor[w] + specShiftScale);
+    }
+
+    if ( noOutSamples <= nrSamples ) {
+      /* Divert output first half to overlap buffer if we already got enough output samples. */
+      pOut0 = hMdct->overlap.time + hMdct->ov_offset;
+      hMdct->ov_offset += hMdct->prev_nr + fl/2;
+    } else {
+      /* Account output samples */
+      nrSamples += hMdct->prev_nr + fl/2;
+    }
+
+    /* NR output samples 0 .. NR. -overlap[TL/2..TL/2-NR] */
+    for (i=0; i<hMdct->prev_nr; i++) {
+      FIXP_DBL x = - (*pOvl--);
+      *pOut0 = IMDCT_SCALE_DBL(x);
+      pOut0 ++;
+    }
+
+    if ( noOutSamples <= nrSamples ) {
+      /* Divert output second half to overlap buffer if we already got enough output samples. */
+      pOut1 = hMdct->overlap.time + hMdct->ov_offset + fl/2 - 1;
+      hMdct->ov_offset += fl/2 + nl;
+    } else {
+      pOut1 = pOut0 + (fl - 1);
+      nrSamples += fl/2 + nl;
+    }
+
+    /* output samples before window crossing point NR .. TL/2. -overlap[TL/2-NR..TL/2-NR-FL/2] + current[NR..TL/2] */
+    /* output samples after window crossing point TL/2 .. TL/2+FL/2. -overlap[0..FL/2] - current[TL/2..FL/2] */
+    pCurr = pSpec + tl - fl/2;
+    for (i=0; i<fl/2; i++) {
+      FIXP_DBL x0, x1;
+
+      cplxMult(&x1, &x0, *pCurr++, - *pOvl--, pWindow[i]);
+      *pOut0 = IMDCT_SCALE_DBL(x0);
+      *pOut1 = IMDCT_SCALE_DBL(-x1);
+      pOut0 ++;
+      pOut1 --;
+    }
+    pOut0 += (fl/2);
+
+    /* NL output samples TL/2+FL/2..TL. - current[FL/2..0] */
+    pOut1 += (fl/2) + 1;
+    pCurr = pSpec + tl - fl/2 - 1;
+    for (i=0; i<nl; i++) {
+      FIXP_DBL x = - (*pCurr--);
+      *pOut1 = IMDCT_SCALE_DBL(x);
+      pOut1 ++;
+    }
+
+    /* Set overlap source pointer for next window pOvl = pSpec + tl/2 - 1; */
+    pOvl = pSpec + tl/2 - 1;
+
+    /* Previous window values. */
+    hMdct->prev_nr = nr;
+    hMdct->prev_fr = fr;
+    hMdct->prev_tl = tl;
+    hMdct->prev_wrs = wrs;
+  }
+
+  /* Save overlap */
+  
+  pOvl = hMdct->overlap.freq + hMdct->ov_size - tl/2;
+  FDK_ASSERT(pOvl >= hMdct->overlap.time + hMdct->ov_offset);
+  FDK_ASSERT(tl/2 <= hMdct->ov_size);
+  for (i=0; i<tl/2; i++) {
+    pOvl[i] = spectrum[i+(nSpec-1)*tl];
+  }
+
+  return nrSamples;
+}
+