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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-09-05 13:14:37 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-09-05 13:14:37 +0000
commitfd3b2704efc2b206784615c1a23eb25501842259 (patch)
tree61ba3a8af2a0ae2ac9ec362bbf18b038f5dc0448 /src/share/replaygain_analysis
parentInitial commit. (diff)
downloadflac-fd3b2704efc2b206784615c1a23eb25501842259.tar.xz
flac-fd3b2704efc2b206784615c1a23eb25501842259.zip
Adding upstream version 1.4.3+ds.upstream/1.4.3+dsupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/share/replaygain_analysis')
-rw-r--r--src/share/replaygain_analysis/CMakeLists.txt2
-rw-r--r--src/share/replaygain_analysis/replaygain_analysis.c575
2 files changed, 577 insertions, 0 deletions
diff --git a/src/share/replaygain_analysis/CMakeLists.txt b/src/share/replaygain_analysis/CMakeLists.txt
new file mode 100644
index 0000000..4362b90
--- /dev/null
+++ b/src/share/replaygain_analysis/CMakeLists.txt
@@ -0,0 +1,2 @@
+add_library(replaygain_analysis STATIC
+ replaygain_analysis.c)
diff --git a/src/share/replaygain_analysis/replaygain_analysis.c b/src/share/replaygain_analysis/replaygain_analysis.c
new file mode 100644
index 0000000..37b77ab
--- /dev/null
+++ b/src/share/replaygain_analysis/replaygain_analysis.c
@@ -0,0 +1,575 @@
+/*
+ * ReplayGainAnalysis - analyzes input samples and give the recommended dB change
+ * Copyright (C) 2001 David Robinson and Glen Sawyer
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 (glensawyer@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 ;)
+ *
+ * minor cosmetic tweaks to integrate with FLAC by Josh Coalson
+ *
+ *
+ * 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 flac_float_t* left_samples,
+ * const flac_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:
+ *
+ * flac_float_t l_samples [4096];
+ * flac_float_t r_samples [4096];
+ * size_t num_samples;
+ * uint32_t num_songs;
+ * uint32_t 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include "share/alloc.h"
+#include "share/compat.h"
+#include "share/replaygain_analysis.h"
+
+flac_float_t ReplayGainReferenceLoudness = 89.0; /* in dB SPL */
+
+#define YULE_ORDER 10
+#define BUTTER_ORDER 2
+#define RMS_PERCENTILE 0.95 /* percentile which is louder than the proposed level */
+#define RMS_WINDOW_TIME 50 /* Time slice size [ms] */
+#define STEPS_per_dB 100. /* Table entries per dB */
+#define MAX_dB 120. /* Table entries for 0...MAX_dB (normal max. values are 70...80 dB) */
+
+#define MAX_ORDER (BUTTER_ORDER > YULE_ORDER ? BUTTER_ORDER : YULE_ORDER)
+#define PINK_REF 64.82 /* 298640883795 */ /* calibration value */
+
+static flac_float_t linprebuf [MAX_ORDER * 2];
+static flac_float_t* linpre; /* left input samples, with pre-buffer */
+static flac_float_t* lstepbuf;
+static flac_float_t* lstep; /* left "first step" (i.e. post first filter) samples */
+static flac_float_t* loutbuf;
+static flac_float_t* lout; /* left "out" (i.e. post second filter) samples */
+static flac_float_t rinprebuf [MAX_ORDER * 2];
+static flac_float_t* rinpre; /* right input samples ... */
+static flac_float_t* rstepbuf;
+static flac_float_t* rstep;
+static flac_float_t* routbuf;
+static flac_float_t* rout;
+static uint32_t sampleWindow; /* number of samples required to reach number of milliseconds required for RMS window */
+static uint64_t totsamp;
+static double lsum;
+static double rsum;
+#if 0
+static uint32_t A [(size_t)(STEPS_per_dB * MAX_dB)];
+static uint32_t B [(size_t)(STEPS_per_dB * MAX_dB)];
+#else
+/* [JEC] Solaris Forte compiler doesn't like float calc in array indices */
+static uint32_t A [120 * 100];
+static uint32_t B [120 * 100];
+#endif
+
+#ifdef _MSC_VER
+#pragma warning ( disable : 4305 )
+#endif
+
+struct ReplayGainFilter {
+ long rate;
+ uint32_t downsample;
+ flac_float_t BYule[YULE_ORDER+1];
+ flac_float_t AYule[YULE_ORDER+1];
+ flac_float_t BButter[BUTTER_ORDER+1];
+ flac_float_t AButter[BUTTER_ORDER+1];
+};
+
+static struct ReplayGainFilter *replaygainfilter;
+
+static const struct ReplayGainFilter ReplayGainFilters[] = {
+
+ {
+ 48000, 0, /* ORIGINAL */
+ { 0.03857599435200, -0.02160367184185, -0.00123395316851, -0.00009291677959, -0.01655260341619, 0.02161526843274, -0.02074045215285, 0.00594298065125, 0.00306428023191, 0.00012025322027, 0.00288463683916 },
+ { 1.00000000000000, -3.84664617118067, 7.81501653005538, -11.34170355132042, 13.05504219327545, -12.28759895145294, 9.48293806319790, -5.87257861775999, 2.75465861874613, -0.86984376593551, 0.13919314567432 },
+ { 0.98621192462708, -1.97242384925416, 0.98621192462708 },
+ { 1.00000000000000, -1.97223372919527, 0.97261396931306 },
+ },
+
+ {
+ 44100, 0, /* ORIGINAL */
+ { 0.05418656406430, -0.02911007808948, -0.00848709379851, -0.00851165645469, -0.00834990904936, 0.02245293253339, -0.02596338512915, 0.01624864962975, -0.00240879051584, 0.00674613682247, -0.00187763777362 },
+ { 1.00000000000000, -3.47845948550071, 6.36317777566148, -8.54751527471874, 9.47693607801280, -8.81498681370155, 6.85401540936998, -4.39470996079559, 2.19611684890774, -0.75104302451432, 0.13149317958808 },
+ { 0.98500175787242, -1.97000351574484, 0.98500175787242 },
+ { 1.00000000000000, -1.96977855582618, 0.97022847566350 },
+ },
+
+ {
+ 37800, 0,
+ { 0.10296717174470, -0.04877975583256, -0.02878009075237, -0.03519509188311, 0.02888717172493, -0.00609872684844, 0.00209851217112, 0.00911704668543, 0.01154404718589, -0.00630293688700, 0.00107527155228 },
+ { 1.00000000000000, -2.64848054923531, 3.58406058405771, -3.83794914179161, 3.90142345804575, -3.50179818637243, 2.67085284083076, -1.82581142372418, 1.09530368139801, -0.47689017820395, 0.11171431535905 },
+ { 0.98252400815195, -1.96504801630391, 0.98252400815195 },
+ { 1.00000000000000, -1.96474258269041, 0.96535344991740 },
+ },
+
+ {
+ 36000, 0,
+ { 0.11572297028613, -0.04120916051252, -0.04977731768022, -0.01047308680426, 0.00750863219157, 0.00055507694408, 0.00140344192886, 0.01286095246036, 0.00998223033885, -0.00725013810661, 0.00326503346879 },
+ { 1.00000000000000, -2.43606802820871, 3.01907406973844, -2.90372016038192, 2.67947188094303, -2.17606479220391, 1.44912956803015, -0.87785765549050, 0.53592202672557, -0.26469344817509, 0.07495878059717 },
+ { 0.98165826840326, -1.96331653680652, 0.98165826840326 },
+ { 1.00000000000000, -1.96298008938934, 0.96365298422371 },
+ },
+
+ {
+ 32000, 0, /* ORIGINAL */
+ { 0.15457299681924, -0.09331049056315, -0.06247880153653, 0.02163541888798, -0.05588393329856, 0.04781476674921, 0.00222312597743, 0.03174092540049, -0.01390589421898, 0.00651420667831, -0.00881362733839 },
+ { 1.00000000000000, -2.37898834973084, 2.84868151156327, -2.64577170229825, 2.23697657451713, -1.67148153367602, 1.00595954808547, -0.45953458054983, 0.16378164858596, -0.05032077717131, 0.02347897407020 },
+ { 0.97938932735214, -1.95877865470428, 0.97938932735214 },
+ { 1.00000000000000, -1.95835380975398, 0.95920349965459 },
+ },
+
+ {
+ 28000, 0,
+ { 0.23882392323383, -0.22007791534089, -0.06014581950332, 0.05004458058021, -0.03293111254977, 0.02348678189717, 0.04290549799671, -0.00938141862174, 0.00015095146303, -0.00712601540885, -0.00626520210162 },
+ { 1.00000000000000, -2.06894080899139, 1.76944699577212, -0.81404732584187, 0.25418286850232, -0.30340791669762, 0.35616884070937, -0.14967310591258, -0.07024154183279, 0.11078404345174, -0.03551838002425 },
+ { 0.97647981663949, -1.95295963327897, 0.97647981663949 },
+ { 1.00000000000000, -1.95240635772520, 0.95351290883275 },
+
+ },
+
+ {
+ 24000, 0, /* ORIGINAL */
+ { 0.30296907319327, -0.22613988682123, -0.08587323730772, 0.03282930172664, -0.00915702933434, -0.02364141202522, -0.00584456039913, 0.06276101321749, -0.00000828086748, 0.00205861885564, -0.02950134983287 },
+ { 1.00000000000000, -1.61273165137247, 1.07977492259970, -0.25656257754070, -0.16276719120440, -0.22638893773906, 0.39120800788284, -0.22138138954925, 0.04500235387352, 0.02005851806501, 0.00302439095741 },
+ { 0.97531843204928, -1.95063686409857, 0.97531843204928 },
+ { 1.00000000000000, -1.95002759149878, 0.95124613669835 },
+ },
+
+ {
+ 22050, 0, /* ORIGINAL */
+ { 0.33642304856132, -0.25572241425570, -0.11828570177555, 0.11921148675203, -0.07834489609479, -0.00469977914380, -0.00589500224440, 0.05724228140351, 0.00832043980773, -0.01635381384540, -0.01760176568150 },
+ { 1.00000000000000, -1.49858979367799, 0.87350271418188, 0.12205022308084, -0.80774944671438, 0.47854794562326, -0.12453458140019, -0.04067510197014, 0.08333755284107, -0.04237348025746, 0.02977207319925 },
+ { 0.97316523498161, -1.94633046996323, 0.97316523498161 },
+ { 1.00000000000000, -1.94561023566527, 0.94705070426118 },
+ },
+
+ {
+ 18900, 0,
+ { 0.38412657295385, -0.44533729608120, 0.20426638066221, -0.28031676047946, 0.31484202614802, -0.26078311203207, 0.12925201224848, -0.01141164696062, 0.03036522115769, -0.03776339305406, 0.00692036603586 },
+ { 1.00000000000000, -1.74403915585708, 1.96686095832499, -2.10081452941881, 1.90753918182846, -1.83814263754422, 1.36971352214969, -0.77883609116398, 0.39266422457649, -0.12529383592986, 0.05424760697665 },
+ { 0.96535326815829, -1.93070653631658, 0.96535326815829 },
+ { 1.00000000000000, -1.92950577983524, 0.93190729279793 },
+ },
+
+ {
+ 16000, 0, /* ORIGINAL */
+ { 0.44915256608450, -0.14351757464547, -0.22784394429749, -0.01419140100551, 0.04078262797139, -0.12398163381748, 0.04097565135648, 0.10478503600251, -0.01863887810927, -0.03193428438915, 0.00541907748707 },
+ { 1.00000000000000, -0.62820619233671, 0.29661783706366, -0.37256372942400, 0.00213767857124, -0.42029820170918, 0.22199650564824, 0.00613424350682, 0.06747620744683, 0.05784820375801, 0.03222754072173 },
+ { 0.96454515552826, -1.92909031105652, 0.96454515552826 },
+ { 1.00000000000000, -1.92783286977036, 0.93034775234268 },
+ },
+
+ {
+ 12000, 0, /* ORIGINAL */
+ { 0.56619470757641, -0.75464456939302, 0.16242137742230, 0.16744243493672, -0.18901604199609, 0.30931782841830, -0.27562961986224, 0.00647310677246, 0.08647503780351, -0.03788984554840, -0.00588215443421 },
+ { 1.00000000000000, -1.04800335126349, 0.29156311971249, -0.26806001042947, 0.00819999645858, 0.45054734505008, -0.33032403314006, 0.06739368333110, -0.04784254229033, 0.01639907836189, 0.01807364323573 },
+ { 0.96009142950541, -1.92018285901082, 0.96009142950541 },
+ { 1.00000000000000, -1.91858953033784, 0.92177618768381 },
+ },
+
+ {
+ 11025, 0, /* ORIGINAL */
+ { 0.58100494960553, -0.53174909058578, -0.14289799034253, 0.17520704835522, 0.02377945217615, 0.15558449135573, -0.25344790059353, 0.01628462406333, 0.06920467763959, -0.03721611395801, -0.00749618797172 },
+ { 1.00000000000000, -0.51035327095184, -0.31863563325245, -0.20256413484477, 0.14728154134330, 0.38952639978999, -0.23313271880868, -0.05246019024463, -0.02505961724053, 0.02442357316099, 0.01818801111503 },
+ { 0.95856916599601, -1.91713833199203, 0.95856916599601 },
+ { 1.00000000000000, -1.91542108074780, 0.91885558323625 },
+ },
+
+ {
+ 8000, 0, /* ORIGINAL */
+ { 0.53648789255105, -0.42163034350696, -0.00275953611929, 0.04267842219415, -0.10214864179676, 0.14590772289388, -0.02459864859345, -0.11202315195388, -0.04060034127000, 0.04788665548180, -0.02217936801134 },
+ { 1.00000000000000, -0.25049871956020, -0.43193942311114, -0.03424681017675, -0.04678328784242, 0.26408300200955, 0.15113130533216, -0.17556493366449, -0.18823009262115, 0.05477720428674, 0.04704409688120 },
+ { 0.94597685600279, -1.89195371200558, 0.94597685600279 },
+ { 1.00000000000000, -1.88903307939452, 0.89487434461664 },
+ },
+
+};
+
+#ifdef _MSC_VER
+#pragma warning ( default : 4305 )
+#endif
+
+/* When calling this procedure, make sure that ip[-order] and op[-order] point to real data! */
+
+static void
+filter ( const flac_float_t* input, flac_float_t* output, size_t nSamples, const flac_float_t* a, const flac_float_t* b, size_t order, uint32_t downsample )
+{
+ double y;
+ size_t i;
+ size_t k;
+
+ const flac_float_t* input_head = input;
+ const flac_float_t* input_tail;
+
+ flac_float_t* output_head = output;
+ flac_float_t* output_tail;
+
+ for ( i = 0; i < nSamples; i++, input_head += downsample, ++output_head ) {
+
+ input_tail = input_head;
+ output_tail = output_head;
+
+ y = *input_head * b[0];
+
+ for ( k = 1; k <= order; k++ ) {
+ input_tail -= downsample;
+ --output_tail;
+ y += *input_tail * b[k] - *output_tail * a[k];
+ }
+
+ output[i] = (flac_float_t)y;
+ }
+}
+
+/* returns a INIT_GAIN_ANALYSIS_OK if successful, INIT_GAIN_ANALYSIS_ERROR if not */
+
+static struct ReplayGainFilter*
+CreateGainFilter ( long samplefreq )
+{
+ uint32_t i;
+ long maxrate = 0;
+ uint32_t downsample = 1;
+ struct ReplayGainFilter* gainfilter = malloc(sizeof(*gainfilter));
+
+ if ( !gainfilter )
+ return 0;
+
+ while (1) {
+ for ( i = 0; i < sizeof(ReplayGainFilters)/sizeof(ReplayGainFilters[0]); ++i ) {
+ if (maxrate < ReplayGainFilters[i].rate)
+ maxrate = ReplayGainFilters[i].rate;
+
+ if ( ReplayGainFilters[i].rate == samplefreq ) {
+ *gainfilter = ReplayGainFilters[i];
+ gainfilter->downsample = downsample;
+ return gainfilter;
+ }
+ }
+
+ if (samplefreq < maxrate)
+ break;
+
+ while (samplefreq > maxrate) {
+ downsample *= 2;
+ samplefreq /= 2;
+ }
+ }
+
+ free(gainfilter);
+
+ return 0;
+}
+
+static void*
+ReallocateWindowBuffer(uint32_t window_size, flac_float_t **window_buffer)
+{
+ *window_buffer = safe_realloc_(*window_buffer, sizeof(**window_buffer) * (window_size + MAX_ORDER));
+ return *window_buffer;
+}
+
+static int
+ResetSampleFrequency ( long samplefreq ) {
+ int i;
+
+ free(replaygainfilter);
+
+ replaygainfilter = CreateGainFilter( samplefreq );
+
+ if ( ! replaygainfilter)
+ return INIT_GAIN_ANALYSIS_ERROR;
+
+ sampleWindow =
+ (replaygainfilter->rate * RMS_WINDOW_TIME + 1000-1) / 1000;
+
+ if ( ! ReallocateWindowBuffer(sampleWindow, &lstepbuf) ||
+ ! ReallocateWindowBuffer(sampleWindow, &rstepbuf) ||
+ ! ReallocateWindowBuffer(sampleWindow, &loutbuf) ||
+ ! ReallocateWindowBuffer(sampleWindow, &routbuf) ) {
+
+ return INIT_GAIN_ANALYSIS_ERROR;
+ }
+
+ /* zero out initial values */
+ for ( i = 0; i < MAX_ORDER; i++ )
+ linprebuf[i] = lstepbuf[i] = loutbuf[i] = rinprebuf[i] = rstepbuf[i] = routbuf[i] = 0.;
+
+ lsum = 0.;
+ rsum = 0.;
+ totsamp = 0;
+
+ memset ( A, 0, sizeof(A) );
+
+ return INIT_GAIN_ANALYSIS_OK;
+}
+
+int
+ValidGainFrequency ( long samplefreq )
+{
+ struct ReplayGainFilter* gainfilter = CreateGainFilter( samplefreq );
+
+ if (gainfilter == 0) {
+ return 0;
+ } else {
+ free(gainfilter);
+ return 1;
+ }
+}
+
+int
+InitGainAnalysis ( long samplefreq )
+{
+ if (ResetSampleFrequency(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
+AnalyzeSamples ( const flac_float_t* left_samples, const flac_float_t* right_samples, size_t num_samples, int num_channels )
+{
+ uint32_t downsample = replaygainfilter->downsample;
+ const flac_float_t* curleft;
+ const flac_float_t* curright;
+ long prebufsamples;
+ long batchsamples;
+ long cursamples;
+ long cursamplepos;
+ int i;
+
+ num_samples /= downsample;
+
+ if ( num_samples == 0 )
+ return GAIN_ANALYSIS_OK;
+
+ cursamplepos = 0;
+ batchsamples = num_samples;
+
+ switch ( num_channels) {
+ case 1: right_samples = left_samples;
+ case 2: break;
+ default: return GAIN_ANALYSIS_ERROR;
+ }
+
+ prebufsamples = MAX_ORDER;
+ if ((size_t) prebufsamples > num_samples)
+ prebufsamples = num_samples;
+
+ for ( i = 0; i < prebufsamples; ++i ) {
+ linprebuf[i+MAX_ORDER] = left_samples [i * downsample];
+ rinprebuf[i+MAX_ORDER] = right_samples[i * downsample];
+ }
+
+ while ( batchsamples > 0 ) {
+ cursamples = batchsamples > (long)(sampleWindow-totsamp) ? (long)(sampleWindow - totsamp) : batchsamples;
+ if ( cursamplepos < MAX_ORDER ) {
+ downsample = 1;
+ curleft = linpre+cursamplepos;
+ curright = rinpre+cursamplepos;
+ if (cursamples > MAX_ORDER - cursamplepos )
+ cursamples = MAX_ORDER - cursamplepos;
+ }
+ else {
+ downsample = replaygainfilter->downsample;
+ curleft = left_samples + cursamplepos * downsample;
+ curright = right_samples + cursamplepos * downsample;
+ }
+
+ filter ( curleft , lstep + totsamp, cursamples, replaygainfilter->AYule, replaygainfilter->BYule, YULE_ORDER, downsample );
+ filter ( curright, rstep + totsamp, cursamples, replaygainfilter->AYule, replaygainfilter->BYule, YULE_ORDER, downsample );
+
+ filter ( lstep + totsamp, lout + totsamp, cursamples, replaygainfilter->AButter, replaygainfilter->BButter, BUTTER_ORDER, 1 );
+ filter ( rstep + totsamp, rout + totsamp, cursamples, replaygainfilter->AButter, replaygainfilter->BButter, BUTTER_ORDER, 1 );
+
+ for ( i = 0; i < cursamples; i++ ) { /* Get the squared values */
+ lsum += lout [totsamp+i] * lout [totsamp+i];
+ rsum += rout [totsamp+i] * rout [totsamp+i];
+ }
+
+ batchsamples -= cursamples;
+ cursamplepos += cursamples;
+ totsamp += cursamples;
+ if ( totsamp == sampleWindow ) { /* Get the Root Mean Square (RMS) for this set of samples */
+ double val = STEPS_per_dB * 10. * log10 ( (lsum+rsum) / totsamp * 0.5 + 1.e-37 );
+ int ival = (int) val;
+ if ( ival < 0 ) ival = 0;
+ if ( ival >= (int)(sizeof(A)/sizeof(*A)) ) ival = (int)(sizeof(A)/sizeof(*A)) - 1;
+ A [ival]++;
+ lsum = rsum = 0.;
+ memmove ( loutbuf , loutbuf + totsamp, MAX_ORDER * sizeof(flac_float_t) );
+ memmove ( routbuf , routbuf + totsamp, MAX_ORDER * sizeof(flac_float_t) );
+ memmove ( lstepbuf, lstepbuf + totsamp, MAX_ORDER * sizeof(flac_float_t) );
+ memmove ( rstepbuf, rstepbuf + totsamp, MAX_ORDER * sizeof(flac_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(flac_float_t) );
+ memmove ( rinprebuf, rinprebuf + num_samples, (MAX_ORDER-num_samples) * sizeof(flac_float_t) );
+ memcpy ( linprebuf + MAX_ORDER - num_samples, left_samples, num_samples * sizeof(flac_float_t) );
+ memcpy ( rinprebuf + MAX_ORDER - num_samples, right_samples, num_samples * sizeof(flac_float_t) );
+ }
+ else {
+ downsample = replaygainfilter->downsample;
+
+ left_samples += (num_samples - MAX_ORDER) * downsample;
+ right_samples += (num_samples - MAX_ORDER) * downsample;
+
+ for ( i = 0; i < MAX_ORDER; ++i ) {
+ linprebuf[i] = left_samples [i * downsample];
+ rinprebuf[i] = right_samples[i * downsample];
+ }
+ }
+
+ return GAIN_ANALYSIS_OK;
+}
+
+
+static flac_float_t
+analyzeResult ( uint32_t* Array, size_t len )
+{
+ uint32_t elems;
+ int32_t upper;
+ size_t i;
+
+ elems = 0;
+ for ( i = 0; i < len; i++ )
+ elems += Array[i];
+ if ( elems == 0 )
+ return GAIN_NOT_ENOUGH_SAMPLES;
+
+/* workaround for GCC bug #61423: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61423 */
+#if 0
+ upper = (int32_t) ceil (elems * (1. - RMS_PERCENTILE));
+#else
+ upper = (int32_t) (elems / 20 + ((elems % 20) ? 1 : 0));
+#endif
+ for ( i = len; i-- > 0; ) {
+ if ( (upper -= Array[i]) <= 0 )
+ break;
+ }
+
+ return (flac_float_t) ((flac_float_t)PINK_REF - (flac_float_t)i / (flac_float_t)STEPS_per_dB);
+}
+
+
+flac_float_t
+GetTitleGain ( void )
+{
+ flac_float_t retval;
+ uint32_t 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;
+}
+
+
+flac_float_t
+GetAlbumGain ( void )
+{
+ return analyzeResult ( B, sizeof(B)/sizeof(*B) );
+}
+
+/* end of replaygain_analysis.c */