diff options
Diffstat (limited to 'libSBRdec/src/sbrdec_freq_sca.cpp')
| -rw-r--r-- | libSBRdec/src/sbrdec_freq_sca.cpp | 749 |
1 files changed, 749 insertions, 0 deletions
diff --git a/libSBRdec/src/sbrdec_freq_sca.cpp b/libSBRdec/src/sbrdec_freq_sca.cpp new file mode 100644 index 0000000..f48c7d0 --- /dev/null +++ b/libSBRdec/src/sbrdec_freq_sca.cpp @@ -0,0 +1,749 @@ +/**************************************************************************** + + (C) Copyright Fraunhofer IIS (2004) + 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. + + + 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. + + $Id$ + +*******************************************************************************/ +/*! + \file + \brief Frequency scale calculation $Revision: 36841 $ +*/ + +#include "sbrdec_freq_sca.h" + +#include "transcendent.h" +#include "sbr_rom.h" +#include "env_extr.h" + +#include "genericStds.h" /* need log() for debug-code only */ + +#define MAX_OCTAVE 29 +#define MAX_SECOND_REGION 50 + + +static int numberOfBands(FIXP_SGL bpo_div16, int start, int stop, int warpFlag); +static void CalcBands(UCHAR * diff, UCHAR start, UCHAR stop, UCHAR num_bands); +static SBR_ERROR modifyBands(UCHAR max_band, UCHAR * diff, UCHAR length); +static void cumSum(UCHAR start_value, UCHAR* diff, UCHAR length, UCHAR *start_adress); + + + +/*! + \brief Retrieve QMF-band where the SBR range starts + + Convert startFreq which was read from the bitstream into a + QMF-channel number. + + \return Number of start band +*/ +static UCHAR +getStartBand(UINT fs, /*!< Output sampling frequency */ + UCHAR startFreq, /*!< Index to table of possible start bands */ + UINT headerDataFlags) /*!< Info to SBR mode */ +{ + INT band; + UINT fsMapped; + + fsMapped = fs; + + switch (fsMapped) { + case 48000: + band = FDK_sbrDecoder_sbr_start_freq_48[startFreq]; + break; + case 44100: + band = FDK_sbrDecoder_sbr_start_freq_44[startFreq]; + break; + case 32000: + band = FDK_sbrDecoder_sbr_start_freq_32[startFreq]; + break; + case 24000: + band = FDK_sbrDecoder_sbr_start_freq_24[startFreq]; + break; + case 22050: + band = FDK_sbrDecoder_sbr_start_freq_22[startFreq]; + break; + case 16000: + band = FDK_sbrDecoder_sbr_start_freq_16[startFreq]; + break; + default: + band = 255; + } + + return band; +} + + +/*! + \brief Retrieve QMF-band where the SBR range starts + + Convert startFreq which was read from the bitstream into a + QMF-channel number. + + \return Number of start band +*/ +static UCHAR +getStopBand(UINT fs, /*!< Output sampling frequency */ + UCHAR stopFreq, /*!< Index to table of possible start bands */ + UINT headerDataFlags, /*!< Info to SBR mode */ + UCHAR k0) /*!< Start freq index */ +{ + UCHAR k2; + + if (stopFreq < 14) { + INT stopMin; + UCHAR diff_tot[MAX_OCTAVE + MAX_SECOND_REGION]; + UCHAR *diff0 = diff_tot; + UCHAR *diff1 = diff_tot+MAX_OCTAVE; + + if (fs < 32000) { + stopMin = (((2*6000*2*(64)) / fs) + 1) >> 1; + } + else { + if (fs < 64000) { + stopMin = (((2*8000*2*(64)) / fs) + 1) >> 1; + } + else { + stopMin = (((2*10000*2*(64)) / fs) + 1) >> 1; + } + } + + /* + Choose a stop band between k1 and 64 depending on stopFreq (0..13), + based on a logarithmic scale. + The vectors diff0 and diff1 are used temporarily here. + */ + CalcBands( diff0, stopMin, 64, 13); + shellsort( diff0, 13); + cumSum(stopMin, diff0, 13, diff1); + k2 = diff1[stopFreq]; + } + else if (stopFreq==14) + k2 = 2*k0; + else + k2 = 3*k0; + + /* Limit to Nyquist */ + if (k2 > (64)) + k2 = (64); + + + /* Range checks */ + /* 1 <= difference <= 48; 1 <= fs <= 96000 */ + if ( ((k2 - k0) > MAX_FREQ_COEFFS) || (k2 <= k0) ) { + return 255; + } + + if (headerDataFlags & (SBRDEC_SYNTAX_USAC|SBRDEC_SYNTAX_RSVD50)) { + /* 1 <= difference <= 35; 42000 <= fs <= 96000 */ + if ( (fs >= 42000) && ( (k2 - k0) > MAX_FREQ_COEFFS_FS44100 ) ) { + return 255; + } + /* 1 <= difference <= 32; 46009 <= fs <= 96000 */ + if ( (fs >= 46009) && ( (k2 - k0) > MAX_FREQ_COEFFS_FS48000 ) ) { + return 255; + } + } + else { + /* 1 <= difference <= 35; fs == 44100 */ + if ( (fs == 44100) && ( (k2 - k0) > MAX_FREQ_COEFFS_FS44100 ) ) { + return 255; + } + /* 1 <= difference <= 32; 48000 <= fs <= 96000 */ + if ( (fs >= 48000) && ( (k2 - k0) > MAX_FREQ_COEFFS_FS48000 ) ) { + return 255; + } + } + + return k2; +} + + +/*! + \brief Generates master frequency tables + + Frequency tables are calculated according to the selected domain + (linear/logarithmic) and granularity. + IEC 14496-3 4.6.18.3.2.1 + + \return errorCode, 0 if successful +*/ +SBR_ERROR +sbrdecUpdateFreqScale(UCHAR * v_k_master, /*!< Master table to be created */ + UCHAR *numMaster, /*!< Number of entries in master table */ + UINT fs, /*!< SBR working sampling rate */ + HANDLE_SBR_HEADER_DATA hHeaderData, /*!< Control data from bitstream */ + UINT flags) +{ + FIXP_SGL bpo_div16; /* bands_per_octave divided by 16 */ + INT dk=0; + + /* Internal variables */ + UCHAR k0, k2, i; + UCHAR num_bands0 = 0; + UCHAR num_bands1 = 0; + UCHAR diff_tot[MAX_OCTAVE + MAX_SECOND_REGION]; + UCHAR *diff0 = diff_tot; + UCHAR *diff1 = diff_tot+MAX_OCTAVE; + INT k2_achived; + INT k2_diff; + INT incr=0; + + /* + Determine start band + */ + k0 = getStartBand(fs, hHeaderData->bs_data.startFreq, flags); + if (k0 == 255) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + + /* + Determine stop band + */ + k2 = getStopBand(fs, hHeaderData->bs_data.stopFreq, flags, k0); + if (k2 == 255) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + + if(hHeaderData->bs_data.freqScale>0) { /* Bark */ + INT k1; + + if(hHeaderData->bs_data.freqScale==1) { + bpo_div16 = FL2FXCONST_SGL(12.0f/16.0f); + } + else if(hHeaderData->bs_data.freqScale==2) { + bpo_div16 = FL2FXCONST_SGL(10.0f/16.0f); + } + else { + bpo_div16 = FL2FXCONST_SGL(8.0f/16.0f); + } + + + if( 1000 * k2 > 2245 * k0 ) { /* Two or more regions */ + k1 = 2*k0; + + num_bands0 = numberOfBands(bpo_div16, k0, k1, 0); + num_bands1 = numberOfBands(bpo_div16, k1, k2, hHeaderData->bs_data.alterScale ); + if ( num_bands0 < 1) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + if ( num_bands1 < 1 ) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + + CalcBands(diff0, k0, k1, num_bands0); + shellsort( diff0, num_bands0); + if (diff0[0] == 0) { +#ifdef DEBUG_TOOLS +#endif + return SBRDEC_UNSUPPORTED_CONFIG; + } + + cumSum(k0, diff0, num_bands0, v_k_master); + + CalcBands(diff1, k1, k2, num_bands1); + shellsort( diff1, num_bands1); + if(diff0[num_bands0-1] > diff1[0]) { + SBR_ERROR err; + + err = modifyBands(diff0[num_bands0-1],diff1, num_bands1); + if (err) + return SBRDEC_UNSUPPORTED_CONFIG; + } + + /* Add 2nd region */ + cumSum(k1, diff1, num_bands1, &v_k_master[num_bands0]); + *numMaster = num_bands0 + num_bands1; /* Output nr of bands */ + + } + else { /* Only one region */ + k1=k2; + + num_bands0 = numberOfBands(bpo_div16, k0, k1, 0); + if ( num_bands0 < 1) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + CalcBands(diff0, k0, k1, num_bands0); + shellsort(diff0, num_bands0); + if (diff0[0] == 0) { +#ifdef DEBUG_TOOLS +#endif + return SBRDEC_UNSUPPORTED_CONFIG; + } + + cumSum(k0, diff0, num_bands0, v_k_master); + *numMaster = num_bands0; /* Output nr of bands */ + + } + } + else { /* Linear mode */ + if (hHeaderData->bs_data.alterScale==0) { + dk = 1; + /* FLOOR to get to few number of bands (next lower even number) */ + num_bands0 = (k2 - k0) & 254; + } else { + dk = 2; + num_bands0 = ( ((k2 - k0) >> 1) + 1 ) & 254; /* ROUND to the closest fit */ + } + + if (num_bands0 < 1) { + return SBRDEC_UNSUPPORTED_CONFIG; + /* We must return already here because 'i' can become negative below. */ + } + + k2_achived = k0 + num_bands0*dk; + k2_diff = k2 - k2_achived; + + for(i=0;i<num_bands0;i++) + diff_tot[i] = dk; + + /* If linear scale wasn't achieved */ + /* and we got too wide SBR area */ + if (k2_diff < 0) { + incr = 1; + i = 0; + } + + /* If linear scale wasn't achieved */ + /* and we got too small SBR area */ + if (k2_diff > 0) { + incr = -1; + i = num_bands0-1; + } + + /* Adjust diff vector to get sepc. SBR range */ + while (k2_diff != 0) { + diff_tot[i] = diff_tot[i] - incr; + i = i + incr; + k2_diff = k2_diff + incr; + } + + cumSum(k0, diff_tot, num_bands0, v_k_master);/* cumsum */ + *numMaster = num_bands0; /* Output nr of bands */ + } + + if (*numMaster < 1) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + + + /* + Print out the calculated table + */ + + return SBRDEC_OK; +} + + +/*! + \brief Calculate frequency ratio of one SBR band + + All SBR bands should span a constant frequency range in the logarithmic + domain. This function calculates the ratio of any SBR band's upper and lower + frequency. + + \return num_band-th root of k_start/k_stop +*/ +static FIXP_SGL calcFactorPerBand(int k_start, int k_stop, int num_bands) +{ +/* Changes CT fract class -> IIS fract class: + * scaled bandfactor and step 1 bit right to avoid overflow + * use CTdbouble data type */ + FIXP_DBL bandfactor = FL2FXCONST_DBL(0.25f); /* Start value */ + FIXP_DBL step = FL2FXCONST_DBL(0.125f); /* Initial increment for factor */ + + int direction = 1; + +/* Changes CT fract class -> IIS fract class: + * because saturation can't be done in INT IIS, + * changed start and stop data type from FIXP_SGL to FIXP_DBL */ + FIXP_DBL start = k_start << (DFRACT_BITS-8); + FIXP_DBL stop = k_stop << (DFRACT_BITS-8); + + FIXP_DBL temp; + + int j, i=0; + + while ( step > FL2FXCONST_DBL(0.0f)) { + i++; + temp = stop; + + /* Calculate temp^num_bands: */ + for (j=0; j<num_bands; j++) + //temp = fMult(temp,bandfactor); + temp = fMultDiv2(temp,bandfactor)<<2; + + if (temp<start) { /* Factor too strong, make it weaker */ + if (direction == 0) + /* Halfen step. Right shift is not done as fract because otherwise the + lowest bit cannot be cleared due to rounding */ + step = (FIXP_DBL)((LONG)step >> 1); + direction = 1; + bandfactor = bandfactor + step; + } + else { /* Factor is too weak: make it stronger */ + if (direction == 1) + step = (FIXP_DBL)((LONG)step >> 1); + direction = 0; + bandfactor = bandfactor - step; + } + + if (i>100) { + step = FL2FXCONST_DBL(0.0f); + } + } + return FX_DBL2FX_SGL(bandfactor<<1); +} + + +/*! + \brief Calculate number of SBR bands between start and stop band + + Given the number of bands per octave, this function calculates how many + bands fit in the given frequency range. + When the warpFlag is set, the 'band density' is decreased by a factor + of 1/1.3 + + \return number of bands +*/ +static int +numberOfBands(FIXP_SGL bpo_div16, /*!< Input: number of bands per octave divided by 16 */ + int start, /*!< First QMF band of SBR frequency range */ + int stop, /*!< Last QMF band of SBR frequency range + 1 */ + int warpFlag) /*!< Stretching flag */ +{ + FIXP_SGL num_bands_div128; + int num_bands; + + num_bands_div128 = FX_DBL2FX_SGL(fMult(FDK_getNumOctavesDiv8(start,stop),bpo_div16)); + + if (warpFlag) { + /* Apply the warp factor of 1.3 to get wider bands. We use a value + of 32768/25200 instead of the exact value to avoid critical cases + of rounding. + */ + num_bands_div128 = FX_DBL2FX_SGL(fMult(num_bands_div128, FL2FXCONST_SGL(25200.0/32768.0))); + } + + /* add scaled 1 for rounding to even numbers: */ + num_bands_div128 = num_bands_div128 + FL2FXCONST_SGL( 1.0f/128.0f ); + /* scale back to right aligned integer and double the value: */ + num_bands = 2 * ((LONG)num_bands_div128 >> (FRACT_BITS - 7)); + + return(num_bands); +} + + +/*! + \brief Calculate width of SBR bands + + Given the desired number of bands within the SBR frequency range, + this function calculates the width of each SBR band in QMF channels. + The bands get wider from start to stop (bark scale). +*/ +static void +CalcBands(UCHAR * diff, /*!< Vector of widths to be calculated */ + UCHAR start, /*!< Lower end of subband range */ + UCHAR stop, /*!< Upper end of subband range */ + UCHAR num_bands) /*!< Desired number of bands */ +{ + int i; + int previous; + int current; + FIXP_SGL exact, temp; + FIXP_SGL bandfactor = calcFactorPerBand(start, stop, num_bands); + + previous = stop; /* Start with highest QMF channel */ + exact = (FIXP_SGL)(stop << (FRACT_BITS-8)); /* Shift left to gain some accuracy */ + + for(i=num_bands-1; i>=0; i--) { + /* Calculate border of next lower sbr band */ + exact = FX_DBL2FX_SGL(fMult(exact,bandfactor)); + + /* Add scaled 0.5 for rounding: + We use a value 128/256 instead of 0.5 to avoid some critical cases of rounding. */ + temp = exact + FL2FXCONST_SGL(128.0/32768.0); + + /* scale back to right alinged integer: */ + current = (LONG)temp >> (FRACT_BITS-8); + + /* Save width of band i */ + diff[i] = previous - current; + previous = current; + } +} + + +/*! + \brief Calculate cumulated sum vector from delta vector +*/ +static void +cumSum(UCHAR start_value, UCHAR* diff, UCHAR length, UCHAR *start_adress) +{ + int i; + start_adress[0]=start_value; + for(i=1; i<=length; i++) + start_adress[i] = start_adress[i-1] + diff[i-1]; +} + + +/*! + \brief Adapt width of frequency bands in the second region + + If SBR spans more than 2 octaves, the upper part of a bark-frequency-scale + is calculated separately. This function tries to avoid that the second region + starts with a band smaller than the highest band of the first region. +*/ +static SBR_ERROR +modifyBands(UCHAR max_band_previous, UCHAR * diff, UCHAR length) +{ + int change = max_band_previous - diff[0]; + + /* Limit the change so that the last band cannot get narrower than the first one */ + if ( change > (diff[length-1]-diff[0])>>1 ) + change = (diff[length-1]-diff[0])>>1; + + diff[0] += change; + diff[length-1] -= change; + shellsort(diff, length); + + return SBRDEC_OK; +} + + +/*! + \brief Update high resolution frequency band table +*/ +static void +sbrdecUpdateHiRes(UCHAR * h_hires, + UCHAR * num_hires, + UCHAR * v_k_master, + UCHAR num_bands, + UCHAR xover_band) +{ + UCHAR i; + + *num_hires = num_bands-xover_band; + + for(i=xover_band; i<=num_bands; i++) { + h_hires[i-xover_band] = v_k_master[i]; + } +} + + +/*! + \brief Build low resolution table out of high resolution table +*/ +static void +sbrdecUpdateLoRes(UCHAR * h_lores, + UCHAR * num_lores, + UCHAR * h_hires, + UCHAR num_hires) +{ + UCHAR i; + + if( (num_hires & 1) == 0) { + /* If even number of hires bands */ + *num_lores = num_hires >> 1; + /* Use every second lores=hires[0,2,4...] */ + for(i=0; i<=*num_lores; i++) + h_lores[i] = h_hires[i*2]; + } + else { + /* Odd number of hires, which means xover is odd */ + *num_lores = (num_hires+1) >> 1; + /* Use lores=hires[0,1,3,5 ...] */ + h_lores[0] = h_hires[0]; + for(i=1; i<=*num_lores; i++) { + h_lores[i] = h_hires[i*2-1]; + } + } +} + + +/*! + \brief Derive a low-resolution frequency-table from the master frequency table +*/ +void +sbrdecDownSampleLoRes(UCHAR *v_result, + UCHAR num_result, + UCHAR *freqBandTableRef, + UCHAR num_Ref) +{ + int step; + int i,j; + int org_length,result_length; + int v_index[MAX_FREQ_COEFFS>>1]; + + /* init */ + org_length = num_Ref; + result_length = num_result; + + v_index[0] = 0; /* Always use left border */ + i=0; + while(org_length > 0) { + /* Create downsample vector */ + i++; + step = org_length / result_length; + org_length = org_length - step; + result_length--; + v_index[i] = v_index[i-1] + step; + } + + for(j=0;j<=i;j++) { + /* Use downsample vector to index LoResolution vector */ + v_result[j]=freqBandTableRef[v_index[j]]; + } + +} + + +/*! + \brief Sorting routine +*/ +void shellsort(UCHAR *in, UCHAR n) +{ + + int i, j, v, w; + int inc = 1; + + do + inc = 3 * inc + 1; + while (inc <= n); + + do { + inc = inc / 3; + for (i = inc; i < n; i++) { + v = in[i]; + j = i; + while ((w=in[j-inc]) > v) { + in[j] = w; + j -= inc; + if (j < inc) + break; + } + in[j] = v; + } + } while (inc > 1); + +} + + + +/*! + \brief Reset frequency band tables + \return errorCode, 0 if successful +*/ +SBR_ERROR +resetFreqBandTables(HANDLE_SBR_HEADER_DATA hHeaderData, const UINT flags) +{ + SBR_ERROR err = SBRDEC_OK; + int k2,kx, lsb, usb; + int intTemp; + UCHAR nBandsLo, nBandsHi; + HANDLE_FREQ_BAND_DATA hFreq = &hHeaderData->freqBandData; + + /* Calculate master frequency function */ + err = sbrdecUpdateFreqScale(hFreq->v_k_master, + &hFreq->numMaster, + hHeaderData->sbrProcSmplRate, + hHeaderData, + flags); + + if ( err || (hHeaderData->bs_info.xover_band > hFreq->numMaster) ) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + + /* Derive Hiresolution from master frequency function */ + sbrdecUpdateHiRes(hFreq->freqBandTable[1], &nBandsHi, hFreq->v_k_master, hFreq->numMaster, hHeaderData->bs_info.xover_band ); + /* Derive Loresolution from Hiresolution */ + sbrdecUpdateLoRes(hFreq->freqBandTable[0], &nBandsLo, hFreq->freqBandTable[1], nBandsHi); + + + hFreq->nSfb[0] = nBandsLo; + hFreq->nSfb[1] = nBandsHi; + + /* Check index to freqBandTable[0] */ + if ( !(nBandsLo > 0) || (nBandsLo > (MAX_FREQ_COEFFS>>1)) ) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + + lsb = hFreq->freqBandTable[0][0]; + usb = hFreq->freqBandTable[0][nBandsLo]; + + /* Additional check for lsb */ + if ( (lsb > (32)) || (lsb >= usb) ) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + + + /* Calculate number of noise bands */ + + k2 = hFreq->freqBandTable[1][nBandsHi]; + kx = hFreq->freqBandTable[1][0]; + + if (hHeaderData->bs_data.noise_bands == 0) + { + hFreq->nNfb = 1; + } + else /* Calculate no of noise bands 1,2 or 3 bands/octave */ + { + /* Fetch number of octaves divided by 32 */ + intTemp = (LONG)FDK_getNumOctavesDiv8(kx,k2) >> 2; + + /* Integer-Multiplication with number of bands: */ + intTemp = intTemp * hHeaderData->bs_data.noise_bands; + + /* Add scaled 0.5 for rounding: */ + intTemp = intTemp + (LONG)FL2FXCONST_SGL(0.5f/32.0f); + + /* Convert to right-aligned integer: */ + intTemp = intTemp >> (FRACT_BITS - 1 /*sign*/ - 5 /* rescale */); + + /* Compare with float calculation */ + FDK_ASSERT( intTemp == (int)((hHeaderData->bs_data.noise_bands * FDKlog( (float)k2/kx) / (float)(FDKlog(2.0)))+0.5) ); + + if( intTemp==0) + intTemp=1; + + hFreq->nNfb = intTemp; + } + + hFreq->nInvfBands = hFreq->nNfb; + + if( hFreq->nNfb > MAX_NOISE_COEFFS ) { + return SBRDEC_UNSUPPORTED_CONFIG; + } + + /* Get noise bands */ + sbrdecDownSampleLoRes(hFreq->freqBandTableNoise, + hFreq->nNfb, + hFreq->freqBandTable[0], + nBandsLo); + + + + + hFreq->lowSubband = lsb; + hFreq->highSubband = usb; + + return SBRDEC_OK; +} |