| |
| /* ----------------------------------------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2013 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; |
| } |
| |