| |
| /* ----------------------------------------------------------------------------------------------------------- |
| 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 |
| ----------------------------------------------------------------------------------------------------------- */ |
| |
| /*! |
| \file |
| \brief envelope decoding |
| This module provides envelope decoding and error concealment algorithms. The main |
| entry point is decodeSbrData(). |
| |
| \sa decodeSbrData(),\ref documentationOverview |
| */ |
| |
| #include "env_dec.h" |
| |
| #include "env_extr.h" |
| #include "transcendent.h" |
| |
| #include "genericStds.h" |
| |
| |
| static void decodeEnvelope (HANDLE_SBR_HEADER_DATA hHeaderData, |
| HANDLE_SBR_FRAME_DATA h_sbr_data, |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data, |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data_otherChannel); |
| static void sbr_envelope_unmapping (HANDLE_SBR_HEADER_DATA hHeaderData, |
| HANDLE_SBR_FRAME_DATA h_data_left, |
| HANDLE_SBR_FRAME_DATA h_data_right); |
| static void requantizeEnvelopeData (HANDLE_SBR_FRAME_DATA h_sbr_data, |
| int ampResolution); |
| static void deltaToLinearPcmEnvelopeDecoding (HANDLE_SBR_HEADER_DATA hHeaderData, |
| HANDLE_SBR_FRAME_DATA h_sbr_data, |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data); |
| static void decodeNoiseFloorlevels (HANDLE_SBR_HEADER_DATA hHeaderData, |
| HANDLE_SBR_FRAME_DATA h_sbr_data, |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data); |
| static void timeCompensateFirstEnvelope (HANDLE_SBR_HEADER_DATA hHeaderData, |
| HANDLE_SBR_FRAME_DATA h_sbr_data, |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data); |
| static int checkEnvelopeData (HANDLE_SBR_HEADER_DATA hHeaderData, |
| HANDLE_SBR_FRAME_DATA h_sbr_data, |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data); |
| |
| |
| |
| #define SBR_ENERGY_PAN_OFFSET (12 << ENV_EXP_FRACT) |
| #define SBR_MAX_ENERGY (35 << ENV_EXP_FRACT) |
| |
| #define DECAY ( 1 << ENV_EXP_FRACT) |
| |
| #if ENV_EXP_FRACT |
| #define DECAY_COUPLING ( 1 << (ENV_EXP_FRACT-1) ) /*!< corresponds to a value of 0.5 */ |
| #else |
| #define DECAY_COUPLING 1 /*!< If the energy data is not shifted, use 1 instead of 0.5 */ |
| #endif |
| |
| |
| /*! |
| \brief Convert table index |
| */ |
| static int indexLow2High(int offset, /*!< mapping factor */ |
| int index, /*!< index to scalefactor band */ |
| int res) /*!< frequency resolution */ |
| { |
| if(res == 0) |
| { |
| if (offset >= 0) |
| { |
| if (index < offset) |
| return(index); |
| else |
| return(2*index - offset); |
| } |
| else |
| { |
| offset = -offset; |
| if (index < offset) |
| return(2*index+index); |
| else |
| return(2*index + offset); |
| } |
| } |
| else |
| return(index); |
| } |
| |
| |
| /*! |
| \brief Update previous envelope value for delta-coding |
| |
| The current envelope values needs to be stored for delta-coding |
| in the next frame. The stored envelope is always represented with |
| the high frequency resolution. If the current envelope uses the |
| low frequency resolution, the energy value will be mapped to the |
| corresponding high-res bands. |
| */ |
| static void mapLowResEnergyVal(FIXP_SGL currVal, /*!< current energy value */ |
| FIXP_SGL* prevData,/*!< pointer to previous data vector */ |
| int offset, /*!< mapping factor */ |
| int index, /*!< index to scalefactor band */ |
| int res) /*!< frequeny resolution */ |
| { |
| if(res == 0) |
| { |
| if (offset >= 0) |
| { |
| if(index < offset) |
| prevData[index] = currVal; |
| else |
| { |
| prevData[2*index - offset] = currVal; |
| prevData[2*index+1 - offset] = currVal; |
| } |
| } |
| else |
| { |
| offset = -offset; |
| if (index < offset) |
| { |
| prevData[3*index] = currVal; |
| prevData[3*index+1] = currVal; |
| prevData[3*index+2] = currVal; |
| } |
| else |
| { |
| prevData[2*index + offset] = currVal; |
| prevData[2*index + 1 + offset] = currVal; |
| } |
| } |
| } |
| else |
| prevData[index] = currVal; |
| } |
| |
| |
| |
| /*! |
| \brief Convert raw envelope and noisefloor data to energy levels |
| |
| This function is being called by sbrDecoder_ParseElement() and provides two important algorithms: |
| |
| First the function decodes envelopes and noise floor levels as described in requantizeEnvelopeData() |
| and sbr_envelope_unmapping(). The function also implements concealment algorithms in case there are errors |
| within the sbr data. For both operations fractional arithmetic is used. |
| Therefore you might encounter different output values on your target |
| system compared to the reference implementation. |
| */ |
| void |
| decodeSbrData (HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_data_left, /*!< pointer to left channel frame data */ |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data_left, /*!< pointer to left channel previous frame data */ |
| HANDLE_SBR_FRAME_DATA h_data_right, /*!< pointer to right channel frame data */ |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data_right)/*!< pointer to right channel previous frame data */ |
| { |
| FIXP_SGL tempSfbNrgPrev[MAX_FREQ_COEFFS]; |
| int errLeft; |
| |
| /* Save previous energy values to be able to reuse them later for concealment. */ |
| FDKmemcpy (tempSfbNrgPrev, h_prev_data_left->sfb_nrg_prev, MAX_FREQ_COEFFS * sizeof(FIXP_SGL)); |
| |
| decodeEnvelope (hHeaderData, h_data_left, h_prev_data_left, h_prev_data_right); |
| decodeNoiseFloorlevels (hHeaderData, h_data_left, h_prev_data_left); |
| |
| if(h_data_right != NULL) { |
| errLeft = hHeaderData->frameErrorFlag; |
| decodeEnvelope (hHeaderData, h_data_right, h_prev_data_right, h_prev_data_left); |
| decodeNoiseFloorlevels (hHeaderData, h_data_right, h_prev_data_right); |
| |
| if (!errLeft && hHeaderData->frameErrorFlag) { |
| /* If an error occurs in the right channel where the left channel seemed ok, |
| we apply concealment also on the left channel. This ensures that the coupling |
| modes of both channels match and that we have the same number of envelopes in |
| coupling mode. |
| However, as the left channel has already been processed before, the resulting |
| energy levels are not the same as if the left channel had been concealed |
| during the first call of decodeEnvelope(). |
| */ |
| /* Restore previous energy values for concealment, because the values have been |
| overwritten by the first call of decodeEnvelope(). */ |
| FDKmemcpy (h_prev_data_left->sfb_nrg_prev, tempSfbNrgPrev, MAX_FREQ_COEFFS * sizeof(FIXP_SGL)); |
| /* Do concealment */ |
| decodeEnvelope (hHeaderData, h_data_left, h_prev_data_left, h_prev_data_right); |
| } |
| |
| if (h_data_left->coupling) { |
| sbr_envelope_unmapping (hHeaderData, h_data_left, h_data_right); |
| } |
| } |
| |
| /* Display the data for debugging: */ |
| } |
| |
| |
| /*! |
| \brief Convert from coupled channels to independent L/R data |
| */ |
| static void |
| sbr_envelope_unmapping (HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_data_left, /*!< pointer to left channel */ |
| HANDLE_SBR_FRAME_DATA h_data_right) /*!< pointer to right channel */ |
| { |
| int i; |
| FIXP_SGL tempL_m, tempR_m, tempRplus1_m, newL_m, newR_m; |
| SCHAR tempL_e, tempR_e, tempRplus1_e, newL_e, newR_e; |
| |
| |
| /* 1. Unmap (already dequantized) coupled envelope energies */ |
| |
| for (i = 0; i < h_data_left->nScaleFactors; i++) { |
| tempR_m = (FIXP_SGL)((LONG)h_data_right->iEnvelope[i] & MASK_M); |
| tempR_e = (SCHAR)((LONG)h_data_right->iEnvelope[i] & MASK_E); |
| |
| tempR_e -= (18 + NRG_EXP_OFFSET); /* -18 = ld(UNMAPPING_SCALE / h_data_right->nChannels) */ |
| tempL_m = (FIXP_SGL)((LONG)h_data_left->iEnvelope[i] & MASK_M); |
| tempL_e = (SCHAR)((LONG)h_data_left->iEnvelope[i] & MASK_E); |
| |
| tempL_e -= NRG_EXP_OFFSET; |
| |
| /* Calculate tempRight+1 */ |
| FDK_add_MantExp( tempR_m, tempR_e, |
| FL2FXCONST_SGL(0.5f), 1, /* 1.0 */ |
| &tempRplus1_m, &tempRplus1_e); |
| |
| FDK_divide_MantExp( tempL_m, tempL_e+1, /* 2 * tempLeft */ |
| tempRplus1_m, tempRplus1_e, |
| &newR_m, &newR_e ); |
| |
| if (newR_m >= ((FIXP_SGL)MAXVAL_SGL - ROUNDING)) { |
| newR_m >>= 1; |
| newR_e += 1; |
| } |
| |
| newL_m = FX_DBL2FX_SGL(fMult(tempR_m,newR_m)); |
| newL_e = tempR_e + newR_e; |
| |
| h_data_right->iEnvelope[i] = ((FIXP_SGL)((SHORT)(FIXP_SGL)(newR_m + ROUNDING) & MASK_M)) + |
| (FIXP_SGL)((SHORT)(FIXP_SGL)(newR_e + NRG_EXP_OFFSET) & MASK_E); |
| h_data_left->iEnvelope[i] = ((FIXP_SGL)((SHORT)(FIXP_SGL)(newL_m + ROUNDING) & MASK_M)) + |
| (FIXP_SGL)((SHORT)(FIXP_SGL)(newL_e + NRG_EXP_OFFSET) & MASK_E); |
| } |
| |
| /* 2. Dequantize and unmap coupled noise floor levels */ |
| |
| for (i = 0; i < hHeaderData->freqBandData.nNfb * h_data_left->frameInfo.nNoiseEnvelopes; i++) { |
| |
| tempL_e = (SCHAR)(6 - (LONG)h_data_left->sbrNoiseFloorLevel[i]); |
| tempR_e = (SCHAR)((LONG)h_data_right->sbrNoiseFloorLevel[i] - 12) /*SBR_ENERGY_PAN_OFFSET*/; |
| |
| /* Calculate tempR+1 */ |
| FDK_add_MantExp( FL2FXCONST_SGL(0.5f), 1+tempR_e, /* tempR */ |
| FL2FXCONST_SGL(0.5f), 1, /* 1.0 */ |
| &tempRplus1_m, &tempRplus1_e); |
| |
| /* Calculate 2*tempLeft/(tempR+1) */ |
| FDK_divide_MantExp( FL2FXCONST_SGL(0.5f), tempL_e+2, /* 2 * tempLeft */ |
| tempRplus1_m, tempRplus1_e, |
| &newR_m, &newR_e ); |
| |
| /* if (newR_m >= ((FIXP_SGL)MAXVAL_SGL - ROUNDING)) { |
| newR_m >>= 1; |
| newR_e += 1; |
| } */ |
| |
| /* L = tempR * R */ |
| newL_m = newR_m; |
| newL_e = newR_e + tempR_e; |
| h_data_right->sbrNoiseFloorLevel[i] = ((FIXP_SGL)((SHORT)(FIXP_SGL)(newR_m + ROUNDING) & MASK_M)) + |
| (FIXP_SGL)((SHORT)(FIXP_SGL)(newR_e + NOISE_EXP_OFFSET) & MASK_E); |
| h_data_left->sbrNoiseFloorLevel[i] = ((FIXP_SGL)((SHORT)(FIXP_SGL)(newL_m + ROUNDING) & MASK_M)) + |
| (FIXP_SGL)((SHORT)(FIXP_SGL)(newL_e + NOISE_EXP_OFFSET) & MASK_E); |
| } |
| } |
| |
| |
| /*! |
| \brief Simple alternative to the real SBR concealment |
| |
| If the real frameInfo is not available due to a frame loss, a replacement will |
| be constructed with 1 envelope spanning the whole frame (FIX-FIX). |
| The delta-coded energies are set to negative values, resulting in a fade-down. |
| In case of coupling, the balance-channel will move towards the center. |
| */ |
| static void |
| leanSbrConcealment(HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_sbr_data, /*!< pointer to current data */ |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data /*!< pointer to data of last frame */ |
| ) |
| { |
| FIXP_SGL target; /* targeted level for sfb_nrg_prev during fade-down */ |
| FIXP_SGL step; /* speed of fade */ |
| int i; |
| |
| int currentStartPos = h_prev_data->stopPos - hHeaderData->numberTimeSlots; |
| int currentStopPos = hHeaderData->numberTimeSlots; |
| |
| |
| /* Use some settings of the previous frame */ |
| h_sbr_data->ampResolutionCurrentFrame = h_prev_data->ampRes; |
| h_sbr_data->coupling = h_prev_data->coupling; |
| for(i=0;i<MAX_INVF_BANDS;i++) |
| h_sbr_data->sbr_invf_mode[i] = h_prev_data->sbr_invf_mode[i]; |
| |
| /* Generate concealing control data */ |
| |
| h_sbr_data->frameInfo.nEnvelopes = 1; |
| h_sbr_data->frameInfo.borders[0] = currentStartPos; |
| h_sbr_data->frameInfo.borders[1] = currentStopPos; |
| h_sbr_data->frameInfo.freqRes[0] = 1; |
| h_sbr_data->frameInfo.tranEnv = -1; /* no transient */ |
| h_sbr_data->frameInfo.nNoiseEnvelopes = 1; |
| h_sbr_data->frameInfo.bordersNoise[0] = currentStartPos; |
| h_sbr_data->frameInfo.bordersNoise[1] = currentStopPos; |
| |
| h_sbr_data->nScaleFactors = hHeaderData->freqBandData.nSfb[1]; |
| |
| /* Generate fake envelope data */ |
| |
| h_sbr_data->domain_vec[0] = 1; |
| |
| if (h_sbr_data->coupling == COUPLING_BAL) { |
| target = (FIXP_SGL)SBR_ENERGY_PAN_OFFSET; |
| step = (FIXP_SGL)DECAY_COUPLING; |
| } |
| else { |
| target = FL2FXCONST_SGL(0.0f); |
| step = (FIXP_SGL)DECAY; |
| } |
| if (hHeaderData->bs_info.ampResolution == 0) { |
| target <<= 1; |
| step <<= 1; |
| } |
| |
| for (i=0; i < h_sbr_data->nScaleFactors; i++) { |
| if (h_prev_data->sfb_nrg_prev[i] > target) |
| h_sbr_data->iEnvelope[i] = -step; |
| else |
| h_sbr_data->iEnvelope[i] = step; |
| } |
| |
| /* Noisefloor levels are always cleared ... */ |
| |
| h_sbr_data->domain_vec_noise[0] = 1; |
| for (i=0; i < hHeaderData->freqBandData.nNfb; i++) |
| h_sbr_data->sbrNoiseFloorLevel[i] = FL2FXCONST_SGL(0.0f); |
| |
| /* ... and so are the sines */ |
| FDKmemclear(h_sbr_data->addHarmonics, MAX_FREQ_COEFFS); |
| } |
| |
| |
| /*! |
| \brief Build reference energies and noise levels from bitstream elements |
| */ |
| static void |
| decodeEnvelope (HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_sbr_data, /*!< pointer to current data */ |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data, /*!< pointer to data of last frame */ |
| HANDLE_SBR_PREV_FRAME_DATA otherChannel /*!< other channel's last frame data */ |
| ) |
| { |
| int i; |
| int fFrameError = hHeaderData->frameErrorFlag; |
| FIXP_SGL tempSfbNrgPrev[MAX_FREQ_COEFFS]; |
| |
| if (!fFrameError) { |
| /* |
| To avoid distortions after bad frames, set the error flag if delta coding in time occurs. |
| However, SBR can take a little longer to come up again. |
| */ |
| if ( h_prev_data->frameErrorFlag ) { |
| if (h_sbr_data->domain_vec[0] != 0) { |
| fFrameError = 1; |
| } |
| } else { |
| /* Check that the previous stop position and the current start position match. |
| (Could be done in checkFrameInfo(), but the previous frame data is not available there) */ |
| if ( h_sbr_data->frameInfo.borders[0] != h_prev_data->stopPos - hHeaderData->numberTimeSlots ) { |
| /* Both the previous as well as the current frame are flagged to be ok, but they do not match! */ |
| if (h_sbr_data->domain_vec[0] == 1) { |
| /* Prefer concealment over delta-time coding between the mismatching frames */ |
| fFrameError = 1; |
| } |
| else { |
| /* Close the gap in time by triggering timeCompensateFirstEnvelope() */ |
| fFrameError = 1; |
| } |
| } |
| } |
| } |
| |
| |
| if (fFrameError) /* Error is detected */ |
| { |
| leanSbrConcealment(hHeaderData, |
| h_sbr_data, |
| h_prev_data); |
| |
| /* decode the envelope data to linear PCM */ |
| deltaToLinearPcmEnvelopeDecoding (hHeaderData, h_sbr_data, h_prev_data); |
| } |
| else /*Do a temporary dummy decoding and check that the envelope values are within limits */ |
| { |
| if (h_prev_data->frameErrorFlag) { |
| timeCompensateFirstEnvelope (hHeaderData, h_sbr_data, h_prev_data); |
| if (h_sbr_data->coupling != h_prev_data->coupling) { |
| /* |
| Coupling mode has changed during concealment. |
| The stored energy levels need to be converted. |
| */ |
| for (i = 0; i < hHeaderData->freqBandData.nSfb[1]; i++) { |
| /* Former Level-Channel will be used for both channels */ |
| if (h_prev_data->coupling == COUPLING_BAL) |
| h_prev_data->sfb_nrg_prev[i] = otherChannel->sfb_nrg_prev[i]; |
| /* Former L/R will be combined as the new Level-Channel */ |
| else if (h_sbr_data->coupling == COUPLING_LEVEL) |
| h_prev_data->sfb_nrg_prev[i] = (h_prev_data->sfb_nrg_prev[i] + otherChannel->sfb_nrg_prev[i]) >> 1; |
| else if (h_sbr_data->coupling == COUPLING_BAL) |
| h_prev_data->sfb_nrg_prev[i] = (FIXP_SGL)SBR_ENERGY_PAN_OFFSET; |
| } |
| } |
| } |
| FDKmemcpy (tempSfbNrgPrev, h_prev_data->sfb_nrg_prev, |
| MAX_FREQ_COEFFS * sizeof (FIXP_SGL)); |
| |
| deltaToLinearPcmEnvelopeDecoding (hHeaderData, h_sbr_data, h_prev_data); |
| |
| fFrameError = checkEnvelopeData (hHeaderData, h_sbr_data, h_prev_data); |
| |
| if (fFrameError) |
| { |
| hHeaderData->frameErrorFlag = 1; |
| FDKmemcpy (h_prev_data->sfb_nrg_prev, tempSfbNrgPrev, |
| MAX_FREQ_COEFFS * sizeof (FIXP_SGL)); |
| decodeEnvelope (hHeaderData, h_sbr_data, h_prev_data, otherChannel); |
| return; |
| } |
| } |
| |
| requantizeEnvelopeData (h_sbr_data, h_sbr_data->ampResolutionCurrentFrame); |
| |
| hHeaderData->frameErrorFlag = fFrameError; |
| } |
| |
| |
| /*! |
| \brief Verify that envelope energies are within the allowed range |
| \return 0 if all is fine, 1 if an envelope value was too high |
| */ |
| static int |
| checkEnvelopeData (HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_sbr_data, /*!< pointer to current data */ |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data /*!< pointer to data of last frame */ |
| ) |
| { |
| FIXP_SGL *iEnvelope = h_sbr_data->iEnvelope; |
| FIXP_SGL *sfb_nrg_prev = h_prev_data->sfb_nrg_prev; |
| int i = 0, errorFlag = 0; |
| FIXP_SGL sbr_max_energy = |
| (h_sbr_data->ampResolutionCurrentFrame == 1) ? SBR_MAX_ENERGY : (SBR_MAX_ENERGY << 1); |
| |
| /* |
| Range check for current energies |
| */ |
| for (i = 0; i < h_sbr_data->nScaleFactors; i++) { |
| if (iEnvelope[i] > sbr_max_energy) { |
| errorFlag = 1; |
| } |
| if (iEnvelope[i] < FL2FXCONST_SGL(0.0f)) { |
| errorFlag = 1; |
| /* iEnvelope[i] = FL2FXCONST_SGL(0.0f); */ |
| } |
| } |
| |
| /* |
| Range check for previous energies |
| */ |
| for (i = 0; i < hHeaderData->freqBandData.nSfb[1]; i++) { |
| sfb_nrg_prev[i] = fixMax(sfb_nrg_prev[i], FL2FXCONST_SGL(0.0f)); |
| sfb_nrg_prev[i] = fixMin(sfb_nrg_prev[i], sbr_max_energy); |
| } |
| |
| return (errorFlag); |
| } |
| |
| |
| /*! |
| \brief Verify that the noise levels are within the allowed range |
| |
| The function is equivalent to checkEnvelopeData(). |
| When the noise-levels are being decoded, it is already too late for |
| concealment. Therefore the noise levels are simply limited here. |
| */ |
| static void |
| limitNoiseLevels(HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_sbr_data) /*!< pointer to current data */ |
| { |
| int i; |
| int nNfb = hHeaderData->freqBandData.nNfb; |
| |
| /* |
| Set range limits. The exact values depend on the coupling mode. |
| However this limitation is primarily intended to avoid unlimited |
| accumulation of the delta-coded noise levels. |
| */ |
| #define lowerLimit ((FIXP_SGL)0) /* lowerLimit actually refers to the _highest_ noise energy */ |
| #define upperLimit ((FIXP_SGL)35) /* upperLimit actually refers to the _lowest_ noise energy */ |
| |
| /* |
| Range check for current noise levels |
| */ |
| for (i = 0; i < h_sbr_data->frameInfo.nNoiseEnvelopes * nNfb; i++) { |
| h_sbr_data->sbrNoiseFloorLevel[i] = fixMin(h_sbr_data->sbrNoiseFloorLevel[i], upperLimit); |
| h_sbr_data->sbrNoiseFloorLevel[i] = fixMax(h_sbr_data->sbrNoiseFloorLevel[i], lowerLimit); |
| } |
| } |
| |
| |
| /*! |
| \brief Compensate for the wrong timing that might occur after a frame error. |
| */ |
| static void |
| timeCompensateFirstEnvelope (HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_sbr_data, /*!< pointer to actual data */ |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data) /*!< pointer to data of last frame */ |
| { |
| int i, nScalefactors; |
| FRAME_INFO *pFrameInfo = &h_sbr_data->frameInfo; |
| UCHAR *nSfb = hHeaderData->freqBandData.nSfb; |
| int estimatedStartPos = h_prev_data->stopPos - hHeaderData->numberTimeSlots; |
| int refLen, newLen, shift; |
| FIXP_SGL deltaExp; |
| |
| /* Original length of first envelope according to bitstream */ |
| refLen = pFrameInfo->borders[1] - pFrameInfo->borders[0]; |
| /* Corrected length of first envelope (concealing can make the first envelope longer) */ |
| newLen = pFrameInfo->borders[1] - estimatedStartPos; |
| |
| if (newLen <= 0) { |
| /* An envelope length of <= 0 would not work, so we don't use it. |
| May occur if the previous frame was flagged bad due to a mismatch |
| of the old and new frame infos. */ |
| newLen = refLen; |
| estimatedStartPos = pFrameInfo->borders[0]; |
| } |
| |
| deltaExp = FDK_getNumOctavesDiv8(newLen, refLen); |
| |
| /* Shift by -3 to rescale ld-table, 1-ampRes to enable coarser steps */ |
| shift = (FRACT_BITS - 1 - ENV_EXP_FRACT + 1 - h_sbr_data->ampResolutionCurrentFrame - 3); |
| deltaExp = deltaExp >> shift; |
| pFrameInfo->borders[0] = estimatedStartPos; |
| pFrameInfo->bordersNoise[0] = estimatedStartPos; |
| |
| if (h_sbr_data->coupling != COUPLING_BAL) { |
| nScalefactors = (pFrameInfo->freqRes[0]) ? nSfb[1] : nSfb[0]; |
| |
| for (i = 0; i < nScalefactors; i++) |
| h_sbr_data->iEnvelope[i] = h_sbr_data->iEnvelope[i] + deltaExp; |
| } |
| } |
| |
| |
| |
| /*! |
| \brief Convert each envelope value from logarithmic to linear domain |
| |
| Energy levels are transmitted in powers of 2, i.e. only the exponent |
| is extracted from the bitstream. |
| Therefore, normally only integer exponents can occur. However during |
| fading (in case of a corrupt bitstream), a fractional part can also |
| occur. The data in the array iEnvelope is shifted left by ENV_EXP_FRACT |
| compared to an integer representation so that numbers smaller than 1 |
| can be represented. |
| |
| This function calculates a mantissa corresponding to the fractional |
| part of the exponent for each reference energy. The array iEnvelope |
| is converted in place to save memory. Input and output data must |
| be interpreted differently, as shown in the below figure: |
| |
| \image html EnvelopeData.png |
| |
| The data is then used in calculateSbrEnvelope(). |
| */ |
| static void |
| requantizeEnvelopeData (HANDLE_SBR_FRAME_DATA h_sbr_data, int ampResolution) |
| { |
| int i; |
| FIXP_SGL mantissa; |
| int ampShift = 1 - ampResolution; |
| int exponent; |
| |
| /* In case that ENV_EXP_FRACT is changed to something else but 0 or 8, |
| the initialization of this array has to be adapted! |
| */ |
| #if ENV_EXP_FRACT |
| static const FIXP_SGL pow2[ENV_EXP_FRACT] = |
| { |
| FL2FXCONST_SGL(0.5f * pow(2.0f, pow(0.5f, 1))), /* 0.7071 */ |
| FL2FXCONST_SGL(0.5f * pow(2.0f, pow(0.5f, 2))), /* 0.5946 */ |
| FL2FXCONST_SGL(0.5f * pow(2.0f, pow(0.5f, 3))), |
| FL2FXCONST_SGL(0.5f * pow(2.0f, pow(0.5f, 4))), |
| FL2FXCONST_SGL(0.5f * pow(2.0f, pow(0.5f, 5))), |
| FL2FXCONST_SGL(0.5f * pow(2.0f, pow(0.5f, 6))), |
| FL2FXCONST_SGL(0.5f * pow(2.0f, pow(0.5f, 7))), |
| FL2FXCONST_SGL(0.5f * pow(2.0f, pow(0.5f, 8))) /* 0.5013 */ |
| }; |
| |
| int bit, mask; |
| #endif |
| |
| for (i = 0; i < h_sbr_data->nScaleFactors; i++) { |
| exponent = (LONG)h_sbr_data->iEnvelope[i]; |
| |
| #if ENV_EXP_FRACT |
| |
| exponent = exponent >> ampShift; |
| mantissa = 0.5f; |
| |
| /* Amplify mantissa according to the fractional part of the |
| exponent (result will be between 0.500000 and 0.999999) |
| */ |
| mask = 1; /* begin with lowest bit of exponent */ |
| |
| for ( bit=ENV_EXP_FRACT-1; bit>=0; bit-- ) { |
| if (exponent & mask) { |
| /* The current bit of the exponent is set, |
| multiply mantissa with the corresponding factor: */ |
| mantissa = (FIXP_SGL)( (mantissa * pow2[bit]) << 1); |
| } |
| /* Advance to next bit */ |
| mask = mask << 1; |
| } |
| |
| /* Make integer part of exponent right aligned */ |
| exponent = exponent >> ENV_EXP_FRACT; |
| |
| #else |
| /* In case of the high amplitude resolution, 1 bit of the exponent gets lost by the shift. |
| This will be compensated by a mantissa of 0.5*sqrt(2) instead of 0.5 if that bit is 1. */ |
| mantissa = (exponent & ampShift) ? FL2FXCONST_SGL(0.707106781186548f) : FL2FXCONST_SGL(0.5f); |
| exponent = exponent >> ampShift; |
| #endif |
| |
| /* |
| Mantissa was set to 0.5 (instead of 1.0, therefore increase exponent by 1). |
| Multiply by L=nChannels=64 by increasing exponent by another 6. |
| => Increase exponent by 7 |
| */ |
| exponent += 7 + NRG_EXP_OFFSET; |
| |
| /* Combine mantissa and exponent and write back the result */ |
| h_sbr_data->iEnvelope[i] = (FIXP_SGL)(((LONG)mantissa & MASK_M) | (exponent & MASK_E)); |
| |
| } |
| } |
| |
| |
| /*! |
| \brief Build new reference energies from old ones and delta coded data |
| */ |
| static void |
| deltaToLinearPcmEnvelopeDecoding (HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_sbr_data, /*!< pointer to current data */ |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data) /*!< pointer to previous data */ |
| { |
| int i, domain, no_of_bands, band, freqRes; |
| |
| FIXP_SGL *sfb_nrg_prev = h_prev_data->sfb_nrg_prev; |
| FIXP_SGL *ptr_nrg = h_sbr_data->iEnvelope; |
| |
| int offset = 2 * hHeaderData->freqBandData.nSfb[0] - hHeaderData->freqBandData.nSfb[1]; |
| |
| for (i = 0; i < h_sbr_data->frameInfo.nEnvelopes; i++) { |
| domain = h_sbr_data->domain_vec[i]; |
| freqRes = h_sbr_data->frameInfo.freqRes[i]; |
| |
| FDK_ASSERT(freqRes >= 0 && freqRes <= 1); |
| |
| no_of_bands = hHeaderData->freqBandData.nSfb[freqRes]; |
| |
| FDK_ASSERT(no_of_bands < (64)); |
| |
| if (domain == 0) |
| { |
| mapLowResEnergyVal(*ptr_nrg, sfb_nrg_prev, offset, 0, freqRes); |
| ptr_nrg++; |
| for (band = 1; band < no_of_bands; band++) |
| { |
| *ptr_nrg = *ptr_nrg + *(ptr_nrg-1); |
| mapLowResEnergyVal(*ptr_nrg, sfb_nrg_prev, offset, band, freqRes); |
| ptr_nrg++; |
| } |
| } |
| else |
| { |
| for (band = 0; band < no_of_bands; band++) |
| { |
| *ptr_nrg = *ptr_nrg + sfb_nrg_prev[indexLow2High(offset, band, freqRes)]; |
| mapLowResEnergyVal(*ptr_nrg, sfb_nrg_prev, offset, band, freqRes); |
| ptr_nrg++; |
| } |
| } |
| } |
| } |
| |
| |
| /*! |
| \brief Build new noise levels from old ones and delta coded data |
| */ |
| static void |
| decodeNoiseFloorlevels (HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Static control data */ |
| HANDLE_SBR_FRAME_DATA h_sbr_data, /*!< pointer to current data */ |
| HANDLE_SBR_PREV_FRAME_DATA h_prev_data) /*!< pointer to previous data */ |
| { |
| int i; |
| int nNfb = hHeaderData->freqBandData.nNfb; |
| int nNoiseFloorEnvelopes = h_sbr_data->frameInfo.nNoiseEnvelopes; |
| |
| /* Decode first noise envelope */ |
| |
| if (h_sbr_data->domain_vec_noise[0] == 0) { |
| FIXP_SGL noiseLevel = h_sbr_data->sbrNoiseFloorLevel[0]; |
| for (i = 1; i < nNfb; i++) { |
| noiseLevel += h_sbr_data->sbrNoiseFloorLevel[i]; |
| h_sbr_data->sbrNoiseFloorLevel[i] = noiseLevel; |
| } |
| } |
| else { |
| for (i = 0; i < nNfb; i++) { |
| h_sbr_data->sbrNoiseFloorLevel[i] += h_prev_data->prevNoiseLevel[i]; |
| } |
| } |
| |
| /* If present, decode the second noise envelope |
| Note: nNoiseFloorEnvelopes can only be 1 or 2 */ |
| |
| if (nNoiseFloorEnvelopes > 1) { |
| if (h_sbr_data->domain_vec_noise[1] == 0) { |
| FIXP_SGL noiseLevel = h_sbr_data->sbrNoiseFloorLevel[nNfb]; |
| for (i = nNfb + 1; i < 2*nNfb; i++) { |
| noiseLevel += h_sbr_data->sbrNoiseFloorLevel[i]; |
| h_sbr_data->sbrNoiseFloorLevel[i] = noiseLevel; |
| } |
| } |
| else { |
| for (i = 0; i < nNfb; i++) { |
| h_sbr_data->sbrNoiseFloorLevel[i + nNfb] += h_sbr_data->sbrNoiseFloorLevel[i]; |
| } |
| } |
| } |
| |
| limitNoiseLevels(hHeaderData, h_sbr_data); |
| |
| /* Update prevNoiseLevel with the last noise envelope */ |
| for (i = 0; i < nNfb; i++) |
| h_prev_data->prevNoiseLevel[i] = h_sbr_data->sbrNoiseFloorLevel[i + nNfb*(nNoiseFloorEnvelopes-1)]; |
| |
| |
| /* Requantize the noise floor levels in COUPLING_OFF-mode */ |
| if (!h_sbr_data->coupling) { |
| int nf_e; |
| |
| for (i = 0; i < nNoiseFloorEnvelopes*nNfb; i++) { |
| nf_e = 6 - (LONG)h_sbr_data->sbrNoiseFloorLevel[i] + 1 + NOISE_EXP_OFFSET; |
| /* +1 to compensate for a mantissa of 0.5 instead of 1.0 */ |
| |
| h_sbr_data->sbrNoiseFloorLevel[i] = |
| (FIXP_SGL)( ((LONG)FL2FXCONST_SGL(0.5f)) + /* mantissa */ |
| (nf_e & MASK_E) ); /* exponent */ |
| |
| } |
| } |
| } |
