/* * ReplayGainAnalysis - analyzes input samples and give the recommended dB change * Copyright (C) 2001 David Robinson and Glen Sawyer * Improvements and optimizations added by Frank Klemm, and by Marcel Muller * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * concept and filter values by David Robinson (David@Robinson.org) * -- blame him if you think the idea is flawed * original coding by Glen Sawyer (mp3gain@hotmail.com) * -- blame him if you think this runs too slowly, or the coding is otherwise flawed * * lots of code improvements by Frank Klemm ( http://www.uni-jena.de/~pfk/mpp/ ) * -- credit him for all the _good_ programming ;) * * * For an explanation of the concepts and the basic algorithms involved, go to: * http://www.replaygain.org/ */ /* * Here's the deal. Call * * InitGainAnalysis ( long samplefreq ); * * to initialize everything. Call * * AnalyzeSamples ( const Float_t* left_samples, * const Float_t* right_samples, * size_t num_samples, * int num_channels ); * * as many times as you want, with as many or as few samples as you want. * If mono, pass the sample buffer in through left_samples, leave * right_samples NULL, and make sure num_channels = 1. * * GetTitleGain() * * will return the recommended dB level change for all samples analyzed * SINCE THE LAST TIME you called GetTitleGain() OR InitGainAnalysis(). * * GetAlbumGain() * * will return the recommended dB level change for all samples analyzed * since InitGainAnalysis() was called and finalized with GetTitleGain(). * * Pseudo-code to process an album: * * Float_t l_samples [4096]; * Float_t r_samples [4096]; * size_t num_samples; * unsigned int num_songs; * unsigned int i; * * InitGainAnalysis ( 44100 ); * for ( i = 1; i <= num_songs; i++ ) { * while ( ( num_samples = getSongSamples ( song[i], left_samples, right_samples ) ) > 0 ) * AnalyzeSamples ( left_samples, right_samples, num_samples, 2 ); * fprintf ("Recommended dB change for song %2d: %+6.2f dB\n", i, GetTitleGain() ); * } * fprintf ("Recommended dB change for whole album: %+6.2f dB\n", GetAlbumGain() ); */ /* * So here's the main source of potential code confusion: * * The filters applied to the incoming samples are IIR filters, * meaning they rely on up to number of previous samples * AND up to number of previous filtered samples. * * I set up the AnalyzeSamples routine to minimize memory usage and interface * complexity. The speed isn't compromised too much (I don't think), but the * internal complexity is higher than it should be for such a relatively * simple routine. * * Optimization/clarity suggestions are welcome. */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include "lame.h" #include "machine.h" #include "gain_analysis.h" /* for each filter: */ /* [0] 48 kHz, [1] 44.1 kHz, [2] 32 kHz, [3] 24 kHz, [4] 22050 Hz, [5] 16 kHz, [6] 12 kHz, [7] is 11025 Hz, [8] 8 kHz */ #ifdef WIN32 #pragma warning ( disable : 4305 ) #endif /*lint -save -e736 loss of precision */ static const Float_t ABYule[9][multiple_of(4, 2 * YULE_ORDER + 1)] = { /* 20 18 16 14 12 10 8 6 4 2 0 19 17 15 13 11 9 7 5 3 1 */ { 0.00288463683916, 0.00012025322027, 0.00306428023191, 0.00594298065125, -0.02074045215285, 0.02161526843274, -0.01655260341619, -0.00009291677959, -0.00123395316851, -0.02160367184185, 0.03857599435200, 0.13919314567432, -0.86984376593551, 2.75465861874613, -5.87257861775999, 9.48293806319790,-12.28759895145294, 13.05504219327545,-11.34170355132042, 7.81501653005538, -3.84664617118067}, {-0.00187763777362, 0.00674613682247, -0.00240879051584, 0.01624864962975, -0.02596338512915, 0.02245293253339, -0.00834990904936, -0.00851165645469, -0.00848709379851, -0.02911007808948, 0.05418656406430, 0.13149317958808, -0.75104302451432, 2.19611684890774, -4.39470996079559, 6.85401540936998, -8.81498681370155, 9.47693607801280, -8.54751527471874, 6.36317777566148, -3.47845948550071}, {-0.00881362733839, 0.00651420667831, -0.01390589421898, 0.03174092540049, 0.00222312597743, 0.04781476674921, -0.05588393329856, 0.02163541888798, -0.06247880153653, -0.09331049056315, 0.15457299681924, 0.02347897407020, -0.05032077717131, 0.16378164858596, -0.45953458054983, 1.00595954808547, -1.67148153367602, 2.23697657451713, -2.64577170229825, 2.84868151156327, -2.37898834973084}, {-0.02950134983287, 0.00205861885564, -0.00000828086748, 0.06276101321749, -0.00584456039913, -0.02364141202522, -0.00915702933434, 0.03282930172664, -0.08587323730772, -0.22613988682123, 0.30296907319327, 0.00302439095741, 0.02005851806501, 0.04500235387352, -0.22138138954925, 0.39120800788284, -0.22638893773906, -0.16276719120440, -0.25656257754070, 1.07977492259970, -1.61273165137247}, {-0.01760176568150, -0.01635381384540, 0.00832043980773, 0.05724228140351, -0.00589500224440, -0.00469977914380, -0.07834489609479, 0.11921148675203, -0.11828570177555, -0.25572241425570, 0.33642304856132, 0.02977207319925, -0.04237348025746, 0.08333755284107, -0.04067510197014, -0.12453458140019, 0.47854794562326, -0.80774944671438, 0.12205022308084, 0.87350271418188, -1.49858979367799}, { 0.00541907748707, -0.03193428438915, -0.01863887810927, 0.10478503600251, 0.04097565135648, -0.12398163381748, 0.04078262797139, -0.01419140100551, -0.22784394429749, -0.14351757464547, 0.44915256608450, 0.03222754072173, 0.05784820375801, 0.06747620744683, 0.00613424350682, 0.22199650564824, -0.42029820170918, 0.00213767857124, -0.37256372942400, 0.29661783706366, -0.62820619233671}, {-0.00588215443421, -0.03788984554840, 0.08647503780351, 0.00647310677246, -0.27562961986224, 0.30931782841830, -0.18901604199609, 0.16744243493672, 0.16242137742230, -0.75464456939302, 0.56619470757641, 0.01807364323573, 0.01639907836189, -0.04784254229033, 0.06739368333110, -0.33032403314006, 0.45054734505008, 0.00819999645858, -0.26806001042947, 0.29156311971249, -1.04800335126349}, {-0.00749618797172, -0.03721611395801, 0.06920467763959, 0.01628462406333, -0.25344790059353, 0.15558449135573, 0.02377945217615, 0.17520704835522, -0.14289799034253, -0.53174909058578, 0.58100494960553, 0.01818801111503, 0.02442357316099, -0.02505961724053, -0.05246019024463, -0.23313271880868, 0.38952639978999, 0.14728154134330, -0.20256413484477, -0.31863563325245, -0.51035327095184}, {-0.02217936801134, 0.04788665548180, -0.04060034127000, -0.11202315195388, -0.02459864859345, 0.14590772289388, -0.10214864179676, 0.04267842219415, -0.00275953611929, -0.42163034350696, 0.53648789255105, 0.04704409688120, 0.05477720428674, -0.18823009262115, -0.17556493366449, 0.15113130533216, 0.26408300200955, -0.04678328784242, -0.03424681017675, -0.43193942311114, -0.25049871956020} }; static const Float_t ABButter[9][multiple_of(4, 2 * BUTTER_ORDER + 1)] = { /* 5 4 3 2 1 */ {0.98621192462708, 0.97261396931306, -1.97242384925416, -1.97223372919527, 0.98621192462708}, {0.98500175787242, 0.97022847566350, -1.97000351574484, -1.96977855582618, 0.98500175787242}, {0.97938932735214, 0.95920349965459, -1.95877865470428, -1.95835380975398, 0.97938932735214}, {0.97531843204928, 0.95124613669835, -1.95063686409857, -1.95002759149878, 0.97531843204928}, {0.97316523498161, 0.94705070426118, -1.94633046996323, -1.94561023566527, 0.97316523498161}, {0.96454515552826, 0.93034775234268, -1.92909031105652, -1.92783286977036, 0.96454515552826}, {0.96009142950541, 0.92177618768381, -1.92018285901082, -1.91858953033784, 0.96009142950541}, {0.95856916599601, 0.91885558323625, -1.91713833199203, -1.91542108074780, 0.95856916599601}, {0.94597685600279, 0.89487434461664, -1.89195371200558, -1.88903307939452, 0.94597685600279} }; /*lint -restore */ #ifdef WIN32 #pragma warning ( default : 4305 ) #endif /* When calling this procedure, make sure that ip[-order] and op[-order] point to real data! */ static void filterYule(const Float_t * input, Float_t * output, size_t nSamples, const Float_t * const kernel) { while (nSamples--) { Float_t y0 = input[-10] * kernel[ 0]; Float_t y2 = input[ -9] * kernel[ 1]; Float_t y4 = input[ -8] * kernel[ 2]; Float_t y6 = input[ -7] * kernel[ 3]; Float_t s00 = y0 + y2 + y4 + y6; Float_t y8 = input[ -6] * kernel[ 4]; Float_t yA = input[ -5] * kernel[ 5]; Float_t yC = input[ -4] * kernel[ 6]; Float_t yE = input[ -3] * kernel[ 7]; Float_t s01 = y8 + yA + yC + yE; Float_t yG = input[ -2] * kernel[ 8] + input[ -1] * kernel[ 9]; Float_t yK = input[ 0] * kernel[10]; Float_t s1 = s00 + s01 + yG + yK; Float_t x1 = output[-10] * kernel[11] + output[ -9] * kernel[12]; Float_t x5 = output[ -8] * kernel[13] + output[ -7] * kernel[14]; Float_t x9 = output[ -6] * kernel[15] + output[ -5] * kernel[16]; Float_t xD = output[ -4] * kernel[17] + output[ -3] * kernel[18]; Float_t xH = output[ -2] * kernel[19] + output[ -1] * kernel[20]; Float_t s2 = x1 + x5 + x9 + xD + xH; output[0] = (Float_t)(s1 - s2); ++output; ++input; } } static void filterButter(const Float_t * input, Float_t * output, size_t nSamples, const Float_t * const kernel) { while (nSamples--) { Float_t s1 = input[-2] * kernel[0] + input[-1] * kernel[2] + input[ 0] * kernel[4]; Float_t s2 = output[-2] * kernel[1] + output[-1] * kernel[3]; output[0] = (Float_t)(s1 - s2); ++output; ++input; } } static int ResetSampleFrequency(replaygain_t * rgData, long samplefreq); /* returns a INIT_GAIN_ANALYSIS_OK if successful, INIT_GAIN_ANALYSIS_ERROR if not */ int ResetSampleFrequency(replaygain_t * rgData, long samplefreq) { /* zero out initial values, only first MAX_ORDER values */ memset(rgData->linprebuf, 0, MAX_ORDER * sizeof(*rgData->linprebuf)); memset(rgData->rinprebuf, 0, MAX_ORDER * sizeof(*rgData->rinprebuf)); memset(rgData->lstepbuf, 0, MAX_ORDER * sizeof(*rgData->lstepbuf)); memset(rgData->rstepbuf, 0, MAX_ORDER * sizeof(*rgData->rstepbuf)); memset(rgData->loutbuf, 0, MAX_ORDER * sizeof(*rgData->loutbuf)); memset(rgData->routbuf, 0, MAX_ORDER * sizeof(*rgData->routbuf)); switch ((int) (samplefreq)) { case 48000: rgData->freqindex = 0; break; case 44100: rgData->freqindex = 1; break; case 32000: rgData->freqindex = 2; break; case 24000: rgData->freqindex = 3; break; case 22050: rgData->freqindex = 4; break; case 16000: rgData->freqindex = 5; break; case 12000: rgData->freqindex = 6; break; case 11025: rgData->freqindex = 7; break; case 8000: rgData->freqindex = 8; break; default: return INIT_GAIN_ANALYSIS_ERROR; } rgData->sampleWindow = (samplefreq * RMS_WINDOW_TIME_NUMERATOR + RMS_WINDOW_TIME_DENOMINATOR - 1) / RMS_WINDOW_TIME_DENOMINATOR; rgData->lsum = 0.; rgData->rsum = 0.; rgData->totsamp = 0; memset(rgData->A, 0, sizeof(rgData->A)); return INIT_GAIN_ANALYSIS_OK; } int InitGainAnalysis(replaygain_t * rgData, long samplefreq) { if (ResetSampleFrequency(rgData, samplefreq) != INIT_GAIN_ANALYSIS_OK) { return INIT_GAIN_ANALYSIS_ERROR; } rgData->linpre = rgData->linprebuf + MAX_ORDER; rgData->rinpre = rgData->rinprebuf + MAX_ORDER; rgData->lstep = rgData->lstepbuf + MAX_ORDER; rgData->rstep = rgData->rstepbuf + MAX_ORDER; rgData->lout = rgData->loutbuf + MAX_ORDER; rgData->rout = rgData->routbuf + MAX_ORDER; memset(rgData->B, 0, sizeof(rgData->B)); return INIT_GAIN_ANALYSIS_OK; } /* returns GAIN_ANALYSIS_OK if successful, GAIN_ANALYSIS_ERROR if not */ int AnalyzeSamples(replaygain_t * rgData, const Float_t * left_samples, const Float_t * right_samples, size_t num_samples, int num_channels) { const Float_t *curleft; const Float_t *curright; long batchsamples; long cursamples; long cursamplepos; int i; Float_t sum_l, sum_r; if (num_samples == 0) return GAIN_ANALYSIS_OK; cursamplepos = 0; batchsamples = (long) num_samples; switch (num_channels) { case 1: right_samples = left_samples; break; case 2: break; default: return GAIN_ANALYSIS_ERROR; } if (num_samples < MAX_ORDER) { memcpy(rgData->linprebuf + MAX_ORDER, left_samples, num_samples * sizeof(Float_t)); memcpy(rgData->rinprebuf + MAX_ORDER, right_samples, num_samples * sizeof(Float_t)); } else { memcpy(rgData->linprebuf + MAX_ORDER, left_samples, MAX_ORDER * sizeof(Float_t)); memcpy(rgData->rinprebuf + MAX_ORDER, right_samples, MAX_ORDER * sizeof(Float_t)); } while (batchsamples > 0) { cursamples = batchsamples > rgData->sampleWindow - rgData->totsamp ? rgData->sampleWindow - rgData->totsamp : batchsamples; if (cursamplepos < MAX_ORDER) { curleft = rgData->linpre + cursamplepos; curright = rgData->rinpre + cursamplepos; if (cursamples > MAX_ORDER - cursamplepos) cursamples = MAX_ORDER - cursamplepos; } else { curleft = left_samples + cursamplepos; curright = right_samples + cursamplepos; } YULE_FILTER(curleft, rgData->lstep + rgData->totsamp, cursamples, ABYule[rgData->freqindex]); YULE_FILTER(curright, rgData->rstep + rgData->totsamp, cursamples, ABYule[rgData->freqindex]); BUTTER_FILTER(rgData->lstep + rgData->totsamp, rgData->lout + rgData->totsamp, cursamples, ABButter[rgData->freqindex]); BUTTER_FILTER(rgData->rstep + rgData->totsamp, rgData->rout + rgData->totsamp, cursamples, ABButter[rgData->freqindex]); curleft = rgData->lout + rgData->totsamp; /* Get the squared values */ curright = rgData->rout + rgData->totsamp; sum_l = 0; sum_r = 0; i = cursamples & 0x03; while (i--) { Float_t const l = *curleft++; Float_t const r = *curright++; sum_l += l * l; sum_r += r * r; } i = cursamples / 4; while (i--) { Float_t l0 = curleft[0] * curleft[0]; Float_t l1 = curleft[1] * curleft[1]; Float_t l2 = curleft[2] * curleft[2]; Float_t l3 = curleft[3] * curleft[3]; Float_t sl = l0 + l1 + l2 + l3; Float_t r0 = curright[0] * curright[0]; Float_t r1 = curright[1] * curright[1]; Float_t r2 = curright[2] * curright[2]; Float_t r3 = curright[3] * curright[3]; Float_t sr = r0 + r1 + r2 + r3; sum_l += sl; curleft += 4; sum_r += sr; curright += 4; } rgData->lsum += sum_l; rgData->rsum += sum_r; batchsamples -= cursamples; cursamplepos += cursamples; rgData->totsamp += cursamples; if (rgData->totsamp == rgData->sampleWindow) { /* Get the Root Mean Square (RMS) for this set of samples */ double const val = STEPS_per_dB * 10. * log10((rgData->lsum + rgData->rsum) / rgData->totsamp * 0.5 + 1.e-37); size_t ival = (val <= 0) ? 0 : (size_t) val; if (ival >= sizeof(rgData->A) / sizeof(*(rgData->A))) ival = sizeof(rgData->A) / sizeof(*(rgData->A)) - 1; rgData->A[ival]++; rgData->lsum = rgData->rsum = 0.; memmove(rgData->loutbuf, rgData->loutbuf + rgData->totsamp, MAX_ORDER * sizeof(Float_t)); memmove(rgData->routbuf, rgData->routbuf + rgData->totsamp, MAX_ORDER * sizeof(Float_t)); memmove(rgData->lstepbuf, rgData->lstepbuf + rgData->totsamp, MAX_ORDER * sizeof(Float_t)); memmove(rgData->rstepbuf, rgData->rstepbuf + rgData->totsamp, MAX_ORDER * sizeof(Float_t)); rgData->totsamp = 0; } if (rgData->totsamp > rgData->sampleWindow) /* somehow I really screwed up: Error in programming! Contact author about totsamp > sampleWindow */ return GAIN_ANALYSIS_ERROR; } if (num_samples < MAX_ORDER) { memmove(rgData->linprebuf, rgData->linprebuf + num_samples, (MAX_ORDER - num_samples) * sizeof(Float_t)); memmove(rgData->rinprebuf, rgData->rinprebuf + num_samples, (MAX_ORDER - num_samples) * sizeof(Float_t)); memcpy(rgData->linprebuf + MAX_ORDER - num_samples, left_samples, num_samples * sizeof(Float_t)); memcpy(rgData->rinprebuf + MAX_ORDER - num_samples, right_samples, num_samples * sizeof(Float_t)); } else { memcpy(rgData->linprebuf, left_samples + num_samples - MAX_ORDER, MAX_ORDER * sizeof(Float_t)); memcpy(rgData->rinprebuf, right_samples + num_samples - MAX_ORDER, MAX_ORDER * sizeof(Float_t)); } return GAIN_ANALYSIS_OK; } static Float_t analyzeResult(uint32_t const *Array, size_t len) { uint32_t elems; uint32_t upper; uint32_t sum; size_t i; elems = 0; for (i = 0; i < len; i++) elems += Array[i]; if (elems == 0) return GAIN_NOT_ENOUGH_SAMPLES; upper = (uint32_t) ceil(elems * (1. - RMS_PERCENTILE)); sum = 0; for (i = len; i-- > 0;) { sum += Array[i]; if (sum >= upper) { break; } } return (Float_t) ((Float_t) PINK_REF - (Float_t) i / (Float_t) STEPS_per_dB); } Float_t GetTitleGain(replaygain_t * rgData) { Float_t retval; unsigned int i; retval = analyzeResult(rgData->A, sizeof(rgData->A) / sizeof(*(rgData->A))); for (i = 0; i < sizeof(rgData->A) / sizeof(*(rgData->A)); i++) { rgData->B[i] += rgData->A[i]; rgData->A[i] = 0; } for (i = 0; i < MAX_ORDER; i++) rgData->linprebuf[i] = rgData->lstepbuf[i] = rgData->loutbuf[i] = rgData->rinprebuf[i] = rgData->rstepbuf[i] = rgData->routbuf[i] = 0.f; rgData->totsamp = 0; rgData->lsum = rgData->rsum = 0.; return retval; } #if 0 static Float_t GetAlbumGain(replaygain_t const* rgData); Float_t GetAlbumGain(replaygain_t const* rgData) { return analyzeResult(rgData->B, sizeof(rgData->B) / sizeof(*(rgData->B))); } #endif /* end of gain_analysis.c */