/* 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
*
* 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 <filter order> number of previous samples
* AND up to <filter order> 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.
*/
#include "lame.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.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 replaygain_data::InitGainAnalysis(long samplefreq) {
if (ResetSampleFrequency(this, samplefreq) != INIT_GAIN_ANALYSIS_OK) {
return INIT_GAIN_ANALYSIS_ERROR;
}
linpre = linprebuf + MAX_ORDER;
rinpre = rinprebuf + MAX_ORDER;
lstep = lstepbuf + MAX_ORDER;
rstep = rstepbuf + MAX_ORDER;
lout = loutbuf + MAX_ORDER;
rout = routbuf + MAX_ORDER;
memset(B, 0, sizeof B);
return INIT_GAIN_ANALYSIS_OK;
}
/* returns GAIN_ANALYSIS_OK if successful, GAIN_ANALYSIS_ERROR if not */
int replaygain_data::AnalyzeSamples(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(linprebuf + MAX_ORDER, left_samples, num_samples * sizeof(Float_t));
memcpy(rinprebuf + MAX_ORDER, right_samples, num_samples * sizeof(Float_t));
}
else {
memcpy(linprebuf + MAX_ORDER, left_samples, MAX_ORDER * sizeof(Float_t));
memcpy(rinprebuf + MAX_ORDER, right_samples, MAX_ORDER * sizeof(Float_t));
}
while (batchsamples > 0) {
cursamples = batchsamples > sampleWindow - totsamp ?
sampleWindow - totsamp : batchsamples;
if (cursamplepos < MAX_ORDER) {
curleft = linpre + cursamplepos;
curright = rinpre + cursamplepos;
if (cursamples > MAX_ORDER - cursamplepos)
cursamples = MAX_ORDER - cursamplepos;
}
else {
curleft = left_samples + cursamplepos;
curright = right_samples + cursamplepos;
}
YULE_FILTER(curleft, lstep + totsamp, cursamples,
ABYule[freqindex]);
YULE_FILTER(curright, rstep + totsamp, cursamples,
ABYule[freqindex]);
BUTTER_FILTER(lstep + totsamp, lout + totsamp, cursamples,
ABButter[freqindex]);
BUTTER_FILTER(rstep + totsamp, rout + totsamp, cursamples,
ABButter[freqindex]);
curleft = lout + totsamp; /* Get the squared values */
curright = rout + 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;
}
lsum += sum_l;
rsum += sum_r;
batchsamples -= cursamples;
cursamplepos += cursamples;
totsamp += cursamples;
if (totsamp == sampleWindow) { /* Get the Root Mean Square (RMS) for this set of samples */
double const val =
STEPS_per_dB * 10. * log10((lsum + rsum) / totsamp * 0.5 +
1.e-37);
size_t ival = (val <= 0) ? 0 : (size_t) val;
if (ival >= sizeof(A) / sizeof(*(A)))
ival = sizeof(A) / sizeof(*(A)) - 1;
A[ival]++;
lsum = rsum = 0.;
memmove(loutbuf, loutbuf + totsamp,
MAX_ORDER * sizeof(Float_t));
memmove(routbuf, routbuf + totsamp,
MAX_ORDER * sizeof(Float_t));
memmove(lstepbuf, lstepbuf + totsamp,
MAX_ORDER * sizeof(Float_t));
memmove(rstepbuf, rstepbuf + totsamp,
MAX_ORDER * sizeof(Float_t));
totsamp = 0;
}
if (totsamp > sampleWindow) /* somehow I really screwed up: Error in programming! Contact author about totsamp > sampleWindow */
return GAIN_ANALYSIS_ERROR;
}
if (num_samples < MAX_ORDER) {
memmove(linprebuf, linprebuf + num_samples,
(MAX_ORDER - num_samples) * sizeof(Float_t));
memmove(rinprebuf, rinprebuf + num_samples,
(MAX_ORDER - num_samples) * sizeof(Float_t));
memcpy(linprebuf + MAX_ORDER - num_samples, left_samples,
num_samples * sizeof(Float_t));
memcpy(rinprebuf + MAX_ORDER - num_samples, right_samples,
num_samples * sizeof(Float_t));
}
else {
memcpy(linprebuf, left_samples + num_samples - MAX_ORDER,
MAX_ORDER * sizeof(Float_t));
memcpy(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 replaygain_data::GetTitleGain() {
Float_t retval;
unsigned int i;
retval = analyzeResult(A, sizeof(A) / sizeof(*(A)));
for (i = 0; i < sizeof(A) / sizeof(*(A)); i++) {
B[i] += A[i];
A[i] = 0;
}
for (i = 0; i < MAX_ORDER; i++)
linprebuf[i] = lstepbuf[i]
= loutbuf[i]
= rinprebuf[i]
= rstepbuf[i]
= routbuf[i] = 0.f;
totsamp = 0;
lsum = 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 */
| Detected encoding: ASCII (7 bit) | 2
|