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Diffstat (limited to '3rdparty/libflac/src/share/grabbag/replaygain.c')
-rw-r--r--3rdparty/libflac/src/share/grabbag/replaygain.c668
1 files changed, 668 insertions, 0 deletions
diff --git a/3rdparty/libflac/src/share/grabbag/replaygain.c b/3rdparty/libflac/src/share/grabbag/replaygain.c
new file mode 100644
index 00000000000..b3d3d210e38
--- /dev/null
+++ b/3rdparty/libflac/src/share/grabbag/replaygain.c
@@ -0,0 +1,668 @@
+/* grabbag - Convenience lib for various routines common to several tools
+ * Copyright (C) 2002,2003,2004,2005,2006,2007 Josh Coalson
+ *
+ * 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
+ */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "share/grabbag.h"
+#include "share/replaygain_analysis.h"
+#include "FLAC/assert.h"
+#include "FLAC/metadata.h"
+#include "FLAC/stream_decoder.h"
+#include <locale.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#if defined _MSC_VER || defined __MINGW32__
+#include <io.h> /* for chmod() */
+#endif
+#include <sys/stat.h> /* for stat(), maybe chmod() */
+
+#ifdef local_min
+#undef local_min
+#endif
+#define local_min(a,b) ((a)<(b)?(a):(b))
+
+#ifdef local_max
+#undef local_max
+#endif
+#define local_max(a,b) ((a)>(b)?(a):(b))
+
+static const char *reference_format_ = "%s=%2.1f dB";
+static const char *gain_format_ = "%s=%+2.2f dB";
+static const char *peak_format_ = "%s=%1.8f";
+
+static double album_peak_, title_peak_;
+
+const unsigned GRABBAG__REPLAYGAIN_MAX_TAG_SPACE_REQUIRED = 190;
+/*
+ FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 29 + 1 + 8 +
+ FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 21 + 1 + 10 +
+ FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 21 + 1 + 12 +
+ FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 21 + 1 + 10 +
+ FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN/8 + 21 + 1 + 12
+*/
+
+const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_REFERENCE_LOUDNESS = (const FLAC__byte * const)"REPLAYGAIN_REFERENCE_LOUDNESS";
+const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_TITLE_GAIN = (const FLAC__byte * const)"REPLAYGAIN_TRACK_GAIN";
+const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_TITLE_PEAK = (const FLAC__byte * const)"REPLAYGAIN_TRACK_PEAK";
+const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_ALBUM_GAIN = (const FLAC__byte * const)"REPLAYGAIN_ALBUM_GAIN";
+const FLAC__byte * const GRABBAG__REPLAYGAIN_TAG_ALBUM_PEAK = (const FLAC__byte * const)"REPLAYGAIN_ALBUM_PEAK";
+
+
+static FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
+{
+ FLAC__ASSERT(0 != filename);
+ FLAC__ASSERT(0 != stats);
+ return (0 == stat(filename, stats));
+}
+
+static void set_file_stats_(const char *filename, struct stat *stats)
+{
+ FLAC__ASSERT(0 != filename);
+ FLAC__ASSERT(0 != stats);
+
+ (void)chmod(filename, stats->st_mode);
+}
+
+static FLAC__bool append_tag_(FLAC__StreamMetadata *block, const char *format, const FLAC__byte *name, float value)
+{
+ char buffer[256];
+ char *saved_locale;
+ FLAC__StreamMetadata_VorbisComment_Entry entry;
+
+ FLAC__ASSERT(0 != block);
+ FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+ FLAC__ASSERT(0 != format);
+ FLAC__ASSERT(0 != name);
+
+ buffer[sizeof(buffer)-1] = '\0';
+ /*
+ * We need to save the old locale and switch to "C" because the locale
+ * influences the formatting of %f and we want it a certain way.
+ */
+ saved_locale = strdup(setlocale(LC_ALL, 0));
+ if (0 == saved_locale)
+ return false;
+ setlocale(LC_ALL, "C");
+#if defined _MSC_VER || defined __MINGW32__
+ _snprintf(buffer, sizeof(buffer)-1, format, name, value);
+#else
+ snprintf(buffer, sizeof(buffer)-1, format, name, value);
+#endif
+ setlocale(LC_ALL, saved_locale);
+ free(saved_locale);
+
+ entry.entry = (FLAC__byte *)buffer;
+ entry.length = strlen(buffer);
+
+ return FLAC__metadata_object_vorbiscomment_append_comment(block, entry, /*copy=*/true);
+}
+
+FLAC__bool grabbag__replaygain_is_valid_sample_frequency(unsigned sample_frequency)
+{
+ static const unsigned valid_sample_rates[] = {
+ 8000,
+ 11025,
+ 12000,
+ 16000,
+ 22050,
+ 24000,
+ 32000,
+ 44100,
+ 48000
+ };
+ static const unsigned n_valid_sample_rates = sizeof(valid_sample_rates) / sizeof(valid_sample_rates[0]);
+
+ unsigned i;
+
+ for(i = 0; i < n_valid_sample_rates; i++)
+ if(sample_frequency == valid_sample_rates[i])
+ return true;
+ return false;
+}
+
+FLAC__bool grabbag__replaygain_init(unsigned sample_frequency)
+{
+ title_peak_ = album_peak_ = 0.0;
+ return InitGainAnalysis((long)sample_frequency) == INIT_GAIN_ANALYSIS_OK;
+}
+
+FLAC__bool grabbag__replaygain_analyze(const FLAC__int32 * const input[], FLAC__bool is_stereo, unsigned bps, unsigned samples)
+{
+ /* using a small buffer improves data locality; we'd like it to fit easily in the dcache */
+ static Float_t lbuffer[2048], rbuffer[2048];
+ static const unsigned nbuffer = sizeof(lbuffer) / sizeof(lbuffer[0]);
+ FLAC__int32 block_peak = 0, s;
+ unsigned i, j;
+
+ FLAC__ASSERT(bps >= 4 && bps <= FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE);
+ FLAC__ASSERT(FLAC__MIN_BITS_PER_SAMPLE == 4);
+ /*
+ * We use abs() on a FLAC__int32 which is undefined for the most negative value.
+ * If the reference codec ever handles 32bps we will have to write a special
+ * case here.
+ */
+ FLAC__ASSERT(FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE < 32);
+
+ if(bps == 16) {
+ if(is_stereo) {
+ j = 0;
+ while(samples > 0) {
+ const unsigned n = local_min(samples, nbuffer);
+ for(i = 0; i < n; i++, j++) {
+ s = input[0][j];
+ lbuffer[i] = (Float_t)s;
+ s = abs(s);
+ block_peak = local_max(block_peak, s);
+
+ s = input[1][j];
+ rbuffer[i] = (Float_t)s;
+ s = abs(s);
+ block_peak = local_max(block_peak, s);
+ }
+ samples -= n;
+ if(AnalyzeSamples(lbuffer, rbuffer, n, 2) != GAIN_ANALYSIS_OK)
+ return false;
+ }
+ }
+ else {
+ j = 0;
+ while(samples > 0) {
+ const unsigned n = local_min(samples, nbuffer);
+ for(i = 0; i < n; i++, j++) {
+ s = input[0][j];
+ lbuffer[i] = (Float_t)s;
+ s = abs(s);
+ block_peak = local_max(block_peak, s);
+ }
+ samples -= n;
+ if(AnalyzeSamples(lbuffer, 0, n, 1) != GAIN_ANALYSIS_OK)
+ return false;
+ }
+ }
+ }
+ else { /* bps must be < 32 according to above assertion */
+ const double scale = (
+ (bps > 16)?
+ (double)1. / (double)(1u << (bps - 16)) :
+ (double)(1u << (16 - bps))
+ );
+
+ if(is_stereo) {
+ j = 0;
+ while(samples > 0) {
+ const unsigned n = local_min(samples, nbuffer);
+ for(i = 0; i < n; i++, j++) {
+ s = input[0][j];
+ lbuffer[i] = (Float_t)(scale * (double)s);
+ s = abs(s);
+ block_peak = local_max(block_peak, s);
+
+ s = input[1][j];
+ rbuffer[i] = (Float_t)(scale * (double)s);
+ s = abs(s);
+ block_peak = local_max(block_peak, s);
+ }
+ samples -= n;
+ if(AnalyzeSamples(lbuffer, rbuffer, n, 2) != GAIN_ANALYSIS_OK)
+ return false;
+ }
+ }
+ else {
+ j = 0;
+ while(samples > 0) {
+ const unsigned n = local_min(samples, nbuffer);
+ for(i = 0; i < n; i++, j++) {
+ s = input[0][j];
+ lbuffer[i] = (Float_t)(scale * (double)s);
+ s = abs(s);
+ block_peak = local_max(block_peak, s);
+ }
+ samples -= n;
+ if(AnalyzeSamples(lbuffer, 0, n, 1) != GAIN_ANALYSIS_OK)
+ return false;
+ }
+ }
+ }
+
+ {
+ const double peak_scale = (double)(1u << (bps - 1));
+ double peak = (double)block_peak / peak_scale;
+ if(peak > title_peak_)
+ title_peak_ = peak;
+ if(peak > album_peak_)
+ album_peak_ = peak;
+ }
+
+ return true;
+}
+
+void grabbag__replaygain_get_album(float *gain, float *peak)
+{
+ *gain = (float)GetAlbumGain();
+ *peak = (float)album_peak_;
+ album_peak_ = 0.0;
+}
+
+void grabbag__replaygain_get_title(float *gain, float *peak)
+{
+ *gain = (float)GetTitleGain();
+ *peak = (float)title_peak_;
+ title_peak_ = 0.0;
+}
+
+
+typedef struct {
+ unsigned channels;
+ unsigned bits_per_sample;
+ unsigned sample_rate;
+ FLAC__bool error;
+} DecoderInstance;
+
+static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
+{
+ DecoderInstance *instance = (DecoderInstance*)client_data;
+ const unsigned bits_per_sample = frame->header.bits_per_sample;
+ const unsigned channels = frame->header.channels;
+ const unsigned sample_rate = frame->header.sample_rate;
+ const unsigned samples = frame->header.blocksize;
+
+ (void)decoder;
+
+ if(
+ !instance->error &&
+ (channels == 2 || channels == 1) &&
+ bits_per_sample == instance->bits_per_sample &&
+ channels == instance->channels &&
+ sample_rate == instance->sample_rate
+ ) {
+ instance->error = !grabbag__replaygain_analyze(buffer, channels==2, bits_per_sample, samples);
+ }
+ else {
+ instance->error = true;
+ }
+
+ if(!instance->error)
+ return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
+ else
+ return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
+}
+
+static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
+{
+ DecoderInstance *instance = (DecoderInstance*)client_data;
+
+ (void)decoder;
+
+ if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO) {
+ instance->bits_per_sample = metadata->data.stream_info.bits_per_sample;
+ instance->channels = metadata->data.stream_info.channels;
+ instance->sample_rate = metadata->data.stream_info.sample_rate;
+
+ if(instance->channels != 1 && instance->channels != 2) {
+ instance->error = true;
+ return;
+ }
+
+ if(!grabbag__replaygain_is_valid_sample_frequency(instance->sample_rate)) {
+ instance->error = true;
+ return;
+ }
+ }
+}
+
+static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
+{
+ DecoderInstance *instance = (DecoderInstance*)client_data;
+
+ (void)decoder, (void)status;
+
+ instance->error = true;
+}
+
+const char *grabbag__replaygain_analyze_file(const char *filename, float *title_gain, float *title_peak)
+{
+ DecoderInstance instance;
+ FLAC__StreamDecoder *decoder = FLAC__stream_decoder_new();
+
+ if(0 == decoder)
+ return "memory allocation error";
+
+ instance.error = false;
+
+ /* It does these three by default but lets be explicit: */
+ FLAC__stream_decoder_set_md5_checking(decoder, false);
+ FLAC__stream_decoder_set_metadata_ignore_all(decoder);
+ FLAC__stream_decoder_set_metadata_respond(decoder, FLAC__METADATA_TYPE_STREAMINFO);
+
+ if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &instance) != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
+ FLAC__stream_decoder_delete(decoder);
+ return "initializing decoder";
+ }
+
+ if(!FLAC__stream_decoder_process_until_end_of_stream(decoder) || instance.error) {
+ FLAC__stream_decoder_delete(decoder);
+ return "decoding file";
+ }
+
+ FLAC__stream_decoder_delete(decoder);
+
+ grabbag__replaygain_get_title(title_gain, title_peak);
+
+ return 0;
+}
+
+const char *grabbag__replaygain_store_to_vorbiscomment(FLAC__StreamMetadata *block, float album_gain, float album_peak, float title_gain, float title_peak)
+{
+ const char *error;
+
+ if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_reference(block)))
+ return error;
+
+ if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_title(block, title_gain, title_peak)))
+ return error;
+
+ if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_album(block, album_gain, album_peak)))
+ return error;
+
+ return 0;
+}
+
+const char *grabbag__replaygain_store_to_vorbiscomment_reference(FLAC__StreamMetadata *block)
+{
+ FLAC__ASSERT(0 != block);
+ FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+ if(FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_REFERENCE_LOUDNESS) < 0)
+ return "memory allocation error";
+
+ if(!append_tag_(block, reference_format_, GRABBAG__REPLAYGAIN_TAG_REFERENCE_LOUDNESS, ReplayGainReferenceLoudness))
+ return "memory allocation error";
+
+ return 0;
+}
+
+const char *grabbag__replaygain_store_to_vorbiscomment_album(FLAC__StreamMetadata *block, float album_gain, float album_peak)
+{
+ FLAC__ASSERT(0 != block);
+ FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+ if(
+ FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_ALBUM_GAIN) < 0 ||
+ FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_ALBUM_PEAK) < 0
+ )
+ return "memory allocation error";
+
+ if(
+ !append_tag_(block, gain_format_, GRABBAG__REPLAYGAIN_TAG_ALBUM_GAIN, album_gain) ||
+ !append_tag_(block, peak_format_, GRABBAG__REPLAYGAIN_TAG_ALBUM_PEAK, album_peak)
+ )
+ return "memory allocation error";
+
+ return 0;
+}
+
+const char *grabbag__replaygain_store_to_vorbiscomment_title(FLAC__StreamMetadata *block, float title_gain, float title_peak)
+{
+ FLAC__ASSERT(0 != block);
+ FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+ if(
+ FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_TITLE_GAIN) < 0 ||
+ FLAC__metadata_object_vorbiscomment_remove_entries_matching(block, (const char *)GRABBAG__REPLAYGAIN_TAG_TITLE_PEAK) < 0
+ )
+ return "memory allocation error";
+
+ if(
+ !append_tag_(block, gain_format_, GRABBAG__REPLAYGAIN_TAG_TITLE_GAIN, title_gain) ||
+ !append_tag_(block, peak_format_, GRABBAG__REPLAYGAIN_TAG_TITLE_PEAK, title_peak)
+ )
+ return "memory allocation error";
+
+ return 0;
+}
+
+static const char *store_to_file_pre_(const char *filename, FLAC__Metadata_Chain **chain, FLAC__StreamMetadata **block)
+{
+ FLAC__Metadata_Iterator *iterator;
+ const char *error;
+ FLAC__bool found_vc_block = false;
+
+ if(0 == (*chain = FLAC__metadata_chain_new()))
+ return "memory allocation error";
+
+ if(!FLAC__metadata_chain_read(*chain, filename)) {
+ error = FLAC__Metadata_ChainStatusString[FLAC__metadata_chain_status(*chain)];
+ FLAC__metadata_chain_delete(*chain);
+ return error;
+ }
+
+ if(0 == (iterator = FLAC__metadata_iterator_new())) {
+ FLAC__metadata_chain_delete(*chain);
+ return "memory allocation error";
+ }
+
+ FLAC__metadata_iterator_init(iterator, *chain);
+
+ do {
+ *block = FLAC__metadata_iterator_get_block(iterator);
+ if((*block)->type == FLAC__METADATA_TYPE_VORBIS_COMMENT)
+ found_vc_block = true;
+ } while(!found_vc_block && FLAC__metadata_iterator_next(iterator));
+
+ if(!found_vc_block) {
+ /* create a new block */
+ *block = FLAC__metadata_object_new(FLAC__METADATA_TYPE_VORBIS_COMMENT);
+ if(0 == *block) {
+ FLAC__metadata_chain_delete(*chain);
+ FLAC__metadata_iterator_delete(iterator);
+ return "memory allocation error";
+ }
+ while(FLAC__metadata_iterator_next(iterator))
+ ;
+ if(!FLAC__metadata_iterator_insert_block_after(iterator, *block)) {
+ error = FLAC__Metadata_ChainStatusString[FLAC__metadata_chain_status(*chain)];
+ FLAC__metadata_chain_delete(*chain);
+ FLAC__metadata_iterator_delete(iterator);
+ return error;
+ }
+ /* iterator is left pointing to new block */
+ FLAC__ASSERT(FLAC__metadata_iterator_get_block(iterator) == *block);
+ }
+
+ FLAC__metadata_iterator_delete(iterator);
+
+ FLAC__ASSERT(0 != *block);
+ FLAC__ASSERT((*block)->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+ return 0;
+}
+
+static const char *store_to_file_post_(const char *filename, FLAC__Metadata_Chain *chain, FLAC__bool preserve_modtime)
+{
+ struct stat stats;
+ const FLAC__bool have_stats = get_file_stats_(filename, &stats);
+
+ (void)grabbag__file_change_stats(filename, /*read_only=*/false);
+
+ FLAC__metadata_chain_sort_padding(chain);
+ if(!FLAC__metadata_chain_write(chain, /*use_padding=*/true, preserve_modtime)) {
+ FLAC__metadata_chain_delete(chain);
+ return FLAC__Metadata_ChainStatusString[FLAC__metadata_chain_status(chain)];
+ }
+
+ FLAC__metadata_chain_delete(chain);
+
+ if(have_stats)
+ set_file_stats_(filename, &stats);
+
+ return 0;
+}
+
+const char *grabbag__replaygain_store_to_file(const char *filename, float album_gain, float album_peak, float title_gain, float title_peak, FLAC__bool preserve_modtime)
+{
+ FLAC__Metadata_Chain *chain;
+ FLAC__StreamMetadata *block;
+ const char *error;
+
+ if(0 != (error = store_to_file_pre_(filename, &chain, &block)))
+ return error;
+
+ if(0 != (error = grabbag__replaygain_store_to_vorbiscomment(block, album_gain, album_peak, title_gain, title_peak))) {
+ FLAC__metadata_chain_delete(chain);
+ return error;
+ }
+
+ if(0 != (error = store_to_file_post_(filename, chain, preserve_modtime)))
+ return error;
+
+ return 0;
+}
+
+const char *grabbag__replaygain_store_to_file_reference(const char *filename, FLAC__bool preserve_modtime)
+{
+ FLAC__Metadata_Chain *chain;
+ FLAC__StreamMetadata *block;
+ const char *error;
+
+ if(0 != (error = store_to_file_pre_(filename, &chain, &block)))
+ return error;
+
+ if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_reference(block))) {
+ FLAC__metadata_chain_delete(chain);
+ return error;
+ }
+
+ if(0 != (error = store_to_file_post_(filename, chain, preserve_modtime)))
+ return error;
+
+ return 0;
+}
+
+const char *grabbag__replaygain_store_to_file_album(const char *filename, float album_gain, float album_peak, FLAC__bool preserve_modtime)
+{
+ FLAC__Metadata_Chain *chain;
+ FLAC__StreamMetadata *block;
+ const char *error;
+
+ if(0 != (error = store_to_file_pre_(filename, &chain, &block)))
+ return error;
+
+ if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_album(block, album_gain, album_peak))) {
+ FLAC__metadata_chain_delete(chain);
+ return error;
+ }
+
+ if(0 != (error = store_to_file_post_(filename, chain, preserve_modtime)))
+ return error;
+
+ return 0;
+}
+
+const char *grabbag__replaygain_store_to_file_title(const char *filename, float title_gain, float title_peak, FLAC__bool preserve_modtime)
+{
+ FLAC__Metadata_Chain *chain;
+ FLAC__StreamMetadata *block;
+ const char *error;
+
+ if(0 != (error = store_to_file_pre_(filename, &chain, &block)))
+ return error;
+
+ if(0 != (error = grabbag__replaygain_store_to_vorbiscomment_title(block, title_gain, title_peak))) {
+ FLAC__metadata_chain_delete(chain);
+ return error;
+ }
+
+ if(0 != (error = store_to_file_post_(filename, chain, preserve_modtime)))
+ return error;
+
+ return 0;
+}
+
+static FLAC__bool parse_double_(const FLAC__StreamMetadata_VorbisComment_Entry *entry, double *val)
+{
+ char s[32], *end;
+ const char *p, *q;
+ double v;
+
+ FLAC__ASSERT(0 != entry);
+ FLAC__ASSERT(0 != val);
+
+ p = (const char *)entry->entry;
+ q = strchr(p, '=');
+ if(0 == q)
+ return false;
+ q++;
+ memset(s, 0, sizeof(s)-1);
+ strncpy(s, q, local_min(sizeof(s)-1, entry->length - (q-p)));
+
+ v = strtod(s, &end);
+ if(end == s)
+ return false;
+
+ *val = v;
+ return true;
+}
+
+FLAC__bool grabbag__replaygain_load_from_vorbiscomment(const FLAC__StreamMetadata *block, FLAC__bool album_mode, FLAC__bool strict, double *reference, double *gain, double *peak)
+{
+ int reference_offset, gain_offset, peak_offset;
+
+ FLAC__ASSERT(0 != block);
+ FLAC__ASSERT(0 != reference);
+ FLAC__ASSERT(0 != gain);
+ FLAC__ASSERT(0 != peak);
+ FLAC__ASSERT(block->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+ /* Default to current level until overridden by a detected tag; this
+ * will always be true until we change replaygain_analysis.c
+ */
+ *reference = ReplayGainReferenceLoudness;
+
+ if(0 <= (reference_offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, /*offset=*/0, (const char *)GRABBAG__REPLAYGAIN_TAG_REFERENCE_LOUDNESS)))
+ (void)parse_double_(block->data.vorbis_comment.comments + reference_offset, reference);
+
+ if(0 > (gain_offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, /*offset=*/0, (const char *)(album_mode? GRABBAG__REPLAYGAIN_TAG_ALBUM_GAIN : GRABBAG__REPLAYGAIN_TAG_TITLE_GAIN))))
+ return !strict && grabbag__replaygain_load_from_vorbiscomment(block, !album_mode, /*strict=*/true, reference, gain, peak);
+ if(0 > (peak_offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, /*offset=*/0, (const char *)(album_mode? GRABBAG__REPLAYGAIN_TAG_ALBUM_PEAK : GRABBAG__REPLAYGAIN_TAG_TITLE_PEAK))))
+ return !strict && grabbag__replaygain_load_from_vorbiscomment(block, !album_mode, /*strict=*/true, reference, gain, peak);
+
+ if(!parse_double_(block->data.vorbis_comment.comments + gain_offset, gain))
+ return !strict && grabbag__replaygain_load_from_vorbiscomment(block, !album_mode, /*strict=*/true, reference, gain, peak);
+ if(!parse_double_(block->data.vorbis_comment.comments + peak_offset, peak))
+ return !strict && grabbag__replaygain_load_from_vorbiscomment(block, !album_mode, /*strict=*/true, reference, gain, peak);
+
+ return true;
+}
+
+double grabbag__replaygain_compute_scale_factor(double peak, double gain, double preamp, FLAC__bool prevent_clipping)
+{
+ double scale;
+ FLAC__ASSERT(peak >= 0.0);
+ gain += preamp;
+ scale = (float) pow(10.0, gain * 0.05);
+ if(prevent_clipping && peak > 0.0) {
+ const double max_scale = (float)(1.0 / peak);
+ if(scale > max_scale)
+ scale = max_scale;
+ }
+ return scale;
+}