aboutsummaryrefslogtreecommitdiffstats
path: root/src/decoder/FlacMetadata.cxx
blob: 96dbf2db089703698c6796686b1aaf5202f06158 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/*
 * Copyright (C) 2003-2013 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "FlacMetadata.hxx"
#include "XiphTags.hxx"
#include "MixRampInfo.hxx"
#include "tag/TagHandler.hxx"
#include "tag/TagTable.hxx"
#include "tag/TagBuilder.hxx"
#include "tag/Tag.hxx"
#include "ReplayGainInfo.hxx"
#include "util/ASCII.hxx"
#include "util/SplitString.hxx"

#include <string.h>

static const char *
vorbis_comment_value(const FLAC__StreamMetadata *block,
		     const char *name)
{
	int offset =
		FLAC__metadata_object_vorbiscomment_find_entry_from(block, 0,
								    name);
	if (offset < 0)
		return nullptr;

	size_t name_length = strlen(name);

	const FLAC__StreamMetadata_VorbisComment_Entry &vc =
		block->data.vorbis_comment.comments[offset];
	const char *comment = (const char *)vc.entry;

	/* 1 is for '=' */
	return comment + name_length + 1;
}

static bool
flac_find_float_comment(const FLAC__StreamMetadata *block,
			const char *cmnt, float *fl)
{
	const char *value = vorbis_comment_value(block, cmnt);
	if (value == nullptr)
		return false;

	*fl = (float)atof(value);
	return true;
}

bool
flac_parse_replay_gain(ReplayGainInfo &rgi,
		       const FLAC__StreamMetadata *block)
{
	rgi.Clear();

	bool found = false;
	if (flac_find_float_comment(block, "replaygain_album_gain",
				    &rgi.tuples[REPLAY_GAIN_ALBUM].gain))
		found = true;
	if (flac_find_float_comment(block, "replaygain_album_peak",
				    &rgi.tuples[REPLAY_GAIN_ALBUM].peak))
		found = true;
	if (flac_find_float_comment(block, "replaygain_track_gain",
				    &rgi.tuples[REPLAY_GAIN_TRACK].gain))
		found = true;
	if (flac_find_float_comment(block, "replaygain_track_peak",
				    &rgi.tuples[REPLAY_GAIN_TRACK].peak))
		found = true;

	return found;
}

gcc_pure
static std::string
flac_find_string_comment(const FLAC__StreamMetadata *block, const char *cmnt)
{
	const char *value = vorbis_comment_value(block, cmnt);
	if (value == nullptr)
		return std::string();

	return std::string(value);
}

MixRampInfo
flac_parse_mixramp(const FLAC__StreamMetadata *block)
{
	MixRampInfo mix_ramp;
	mix_ramp.SetStart(flac_find_string_comment(block, "mixramp_start"));
	mix_ramp.SetEnd(flac_find_string_comment(block, "mixramp_end"));
	return mix_ramp;
}

/**
 * Checks if the specified name matches the entry's name, and if yes,
 * returns the comment value;
 */
static const char *
flac_comment_value(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
		   const char *name)
{
	size_t name_length = strlen(name);
	const char *comment = (const char*)entry->entry;

	if (!StringEqualsCaseASCII(comment, name, name_length))
		return nullptr;

	if (comment[name_length] == '=') {
		return comment + name_length + 1;
	}

	return nullptr;
}

/**
 * Check if the comment's name equals the passed name, and if so, copy
 * the comment value into the tag.
 */
static bool
flac_copy_comment(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
		  const char *name, TagType tag_type,
		  const struct tag_handler *handler, void *handler_ctx)
{
	const char *value = flac_comment_value(entry, name);
	if (value != nullptr) {
		tag_handler_invoke_tag(handler, handler_ctx, tag_type, value);
		return true;
	}

	return false;
}

static void
flac_scan_comment(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
		  const struct tag_handler *handler, void *handler_ctx)
{
	if (handler->pair != nullptr) {
		const char *comment = (const char *)entry->entry;
		const SplitString split(comment, '=');
		if (split.IsDefined() && !split.IsEmpty())
			tag_handler_invoke_pair(handler, handler_ctx,
						split.GetFirst(),
						split.GetSecond());
	}

	for (const struct tag_table *i = xiph_tags; i->name != nullptr; ++i)
		if (flac_copy_comment(entry, i->name, i->type,
				      handler, handler_ctx))
			return;

	for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i)
		if (flac_copy_comment(entry,
				      tag_item_names[i], (TagType)i,
				      handler, handler_ctx))
			return;
}

static void
flac_scan_comments(const FLAC__StreamMetadata_VorbisComment *comment,
		   const struct tag_handler *handler, void *handler_ctx)
{
	for (unsigned i = 0; i < comment->num_comments; ++i)
		flac_scan_comment(&comment->comments[i],
				  handler, handler_ctx);
}

void
flac_scan_metadata(const FLAC__StreamMetadata *block,
		   const struct tag_handler *handler, void *handler_ctx)
{
	switch (block->type) {
	case FLAC__METADATA_TYPE_VORBIS_COMMENT:
		flac_scan_comments(&block->data.vorbis_comment,
				   handler, handler_ctx);
		break;

	case FLAC__METADATA_TYPE_STREAMINFO:
		if (block->data.stream_info.sample_rate > 0)
			tag_handler_invoke_duration(handler, handler_ctx,
						    flac_duration(&block->data.stream_info));
		break;

	default:
		break;
	}
}

Tag
flac_vorbis_comments_to_tag(const FLAC__StreamMetadata_VorbisComment *comment)
{
	TagBuilder tag_builder;
	flac_scan_comments(comment, &add_tag_handler, &tag_builder);
	return tag_builder.Commit();
}

void
FlacMetadataChain::Scan(const struct tag_handler *handler, void *handler_ctx)
{
	FLACMetadataIterator iterator(*this);

	do {
		FLAC__StreamMetadata *block = iterator.GetBlock();
		if (block == nullptr)
			break;

		flac_scan_metadata(block, handler, handler_ctx);
	} while (iterator.Next());
}