feat(metadata): 元数据引擎第 2 步——置信度模型 + pending/verified 状态机

之前 evaluate() 写死 0.8、decide() 直接透传,history 参数没人用,
"自学习"只有骨架。这次补上:

置信度(MetadataNormalizer.evaluate)
- 字段来源可追溯:NormalizedMetadata 新增 titleFromTag / artistFromTag / albumFromTag
- 基础分 0.25;标题 +0.20、标题来自标签再 +0.10(文件名当标题则 -0.10)
- 艺术家 +0.15、来自标签 +0.10;专辑 +0.10;年份 +0.03;封面 +0.02
- 历史一致性:同艺人 >=2 条 +0.05,同专辑 >=2 条 +0.03
- 结果 clamp 到 0.05~0.98,且每个加分项写入 evidence,便于日志解释

状态机(MetadataService)
- 只有 confidence>=0.6 且 status=verified 的记录才直接命中
- pending 记录下次播放会重新读取并合并(自修复)
- validation_count 累加;>=2 次且置信度达标才升级为 verified
- 新结果置信度低于旧结果时保留旧字段,只累加验证次数
- 日志输出 status / confidence / validation_count / evidence

测试
- 新增 test/metadata_normalizer_test.dart,9 个用例覆盖来源标记、分级、
  历史加权、证据、阈值;flutter test 全绿

真机验证
- 起播看门狗在真实弱网下触发:23:44:50 打开失败 → 15s 后自动重连 →
  1.4s 出声(open 仅 100ms)
This commit is contained in:
2026-10-23 23:45:29 +08:00
parent a5849969d3
commit 30111a5f0c
4 changed files with 309 additions and 41 deletions
+9
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@@ -57,6 +57,12 @@ class NormalizedMetadata {
final Duration? duration;
final Uint8List? artwork;
/// 字段来源:true 表示来自标签,false 表示从文件名/路径推断。
/// 置信度模型需要区分这两者——"标签里的标题"和"文件名当标题"价值完全不同。
final bool titleFromTag;
final bool artistFromTag;
final bool albumFromTag;
const NormalizedMetadata({
this.title = '',
this.artist = '',
@@ -70,6 +76,9 @@ class NormalizedMetadata {
this.totalDisc = 0,
this.duration,
this.artwork,
this.titleFromTag = false,
this.artistFromTag = false,
this.albumFromTag = false,
});
bool get isEmpty =>
+96 -14
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@@ -4,21 +4,22 @@ import 'metadata_model.dart';
class MetadataNormalizer {
NormalizedMetadata normalize(RawMetadata raw,
{String fileName = '', String filePath = ''}) {
final title = raw.title.trim();
final artist = raw.artist.trim();
final tagTitle = raw.title.trim();
final tagArtist = raw.artist.trim();
final tagAlbum = raw.album.trim();
final finalTitle =
title.isNotEmpty ? title : _inferTitleFromFileName(fileName);
final finalArtist =
artist.isNotEmpty ? artist : _inferArtistFromPath(filePath);
final finalArtist2 = finalArtist.isNotEmpty
? finalArtist
: (raw.performers.isNotEmpty ? raw.performers.first : '未知艺术家');
tagTitle.isNotEmpty ? tagTitle : _inferTitleFromFileName(fileName);
final artistFromPath = _inferArtistFromPath(filePath);
final finalArtist = tagArtist.isNotEmpty
? tagArtist
: (raw.performers.isNotEmpty ? raw.performers.first : artistFromPath);
return NormalizedMetadata(
title: finalTitle,
artist: finalArtist2,
album: raw.album,
artist: finalArtist,
album: tagAlbum,
genres: raw.genres,
performers: raw.performers,
year: raw.year,
@@ -28,6 +29,9 @@ class MetadataNormalizer {
totalDisc: raw.totalDisc,
duration: raw.duration,
artwork: raw.artwork,
titleFromTag: tagTitle.isNotEmpty,
artistFromTag: tagArtist.isNotEmpty || raw.performers.isNotEmpty,
albumFromTag: tagAlbum.isNotEmpty,
);
}
@@ -49,16 +53,94 @@ class MetadataNormalizer {
return '未知艺术家';
}
/// 置信度评估(元数据引擎第 2 步)。
///
/// 设计原则:
/// 1. 标签 >= 推断:来自标签的字段永远比文件名/目录推断更可信;
/// 2. 字段齐全度:标题、艺术家、专辑依次加分;
/// 3. 历史一致性:同一艺人/专辑已有多条可信记录时额外加权,
/// 这是"自学习"的入口——库越大,判断越稳;
/// 4. 可解释:每个加分项都写进 evidence,方便日志与后续调参。
///
/// 分数区间大致:
/// 0.35 只有文件名
/// 0.55 标题来自标签、艺术家靠推断
/// 0.80 标题 + 艺术家都来自标签
/// 0.90 标题 + 艺术家 + 专辑
/// 0.95 以上再加年份/封面/历史一致性
CandidateMetadata evaluate(
NormalizedMetadata normalized, List<Map<String, dynamic>> history) {
// 第一版:直接接受,置信度 0.8
final evidence = <String, double>{};
var confidence = 0.25;
evidence['base'] = 0.25;
if (normalized.title.isNotEmpty) {
confidence += 0.20;
evidence['title'] = 0.20;
}
if (normalized.titleFromTag) {
confidence += 0.10;
evidence['title_from_tag'] = 0.10;
} else if (normalized.title.isNotEmpty) {
// 拿文件名当标题:明确扣分
confidence -= 0.10;
evidence['title_inferred_penalty'] = -0.10;
}
if (normalized.artist.isNotEmpty && normalized.artist != '未知艺术家') {
confidence += 0.15;
evidence['artist'] = 0.15;
}
if (normalized.artistFromTag) {
confidence += 0.10;
evidence['artist_from_tag'] = 0.10;
}
if (normalized.album.isNotEmpty) {
confidence += 0.10;
evidence['album'] = 0.10;
}
if (normalized.year > 0) {
confidence += 0.03;
evidence['year'] = 0.03;
}
if (normalized.artwork != null && normalized.artwork!.isNotEmpty) {
confidence += 0.02;
evidence['artwork'] = 0.02;
}
// ---- 历史一致性(自学习的核心)----
if (history.isNotEmpty) {
final sameArtist = history
.where((row) => (row['artist'] as String?) == normalized.artist)
.length;
if (sameArtist >= 2) {
confidence += 0.05;
evidence['artist_history'] = 0.05;
}
if (normalized.album.isNotEmpty) {
final sameAlbum = history
.where((row) => (row['album'] as String?) == normalized.album)
.length;
if (sameAlbum >= 2) {
confidence += 0.03;
evidence['album_history'] = 0.03;
}
}
}
confidence = confidence.clamp(0.05, 0.98);
return CandidateMetadata(
metadata: normalized,
confidence: 0.8,
evidence: {'normalized': 0.8},
confidence: double.parse(confidence.toStringAsFixed(2)),
evidence: evidence,
);
}
/// 按阈值决定最终元数据。
/// 低于阈值时仍返回数据(用于展示),但 source 标成 pending,
/// 调用方据此累计 validation_count、下次播放重新确认。
FinalMetadata decide(CandidateMetadata candidate, {double threshold = 0.6}) {
return FinalMetadata(
title: candidate.metadata.title,
@@ -76,7 +158,7 @@ class MetadataNormalizer {
totalDisc: candidate.metadata.totalDisc,
duration: candidate.metadata.duration,
artwork: candidate.metadata.artwork,
source: 'normalized',
source: candidate.confidence >= threshold ? 'normalized' : 'pending',
);
}
}
+64 -27
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@@ -70,12 +70,16 @@ class MetadataService {
final stat = await file.stat();
final songKey = _generateSongKey(url, stat.size);
// 3. SQLite 查询(高置信度直接使用)
// 3. SQLite 查询:只有「已验证」的记录才直接返回。
// pending 记录会继续往下走,重新读取并累计 validation_count,
// 这就是自修复:置信度不足的记录会在下次播放时被重新确认。
Map<String, dynamic>? dbSong;
if (!forceRefresh) {
final dbSong = await _db.getSong(songKey);
dbSong = await _db.getSong(songKey);
if (dbSong != null) {
final confidence = (dbSong['confidence'] as num?)?.toDouble() ?? 0.0;
if (confidence >= 0.6) {
final status = dbSong['metadata_status'] as String? ?? 'pending';
if (confidence >= 0.6 && status == 'verified') {
debugPrint(
'📦 [MetadataService] SQLite hit: ${dbSong['title']} - ${dbSong['artist']}');
@@ -104,6 +108,8 @@ class MetadataService {
await _memoryCache.put(fileId, metadata);
return metadata;
}
debugPrint('🔁 [MetadataService] 记录未验证'
'(conf=${confidence.toStringAsFixed(2)}, status=$status),重新确认');
}
}
@@ -117,47 +123,78 @@ class MetadataService {
filePath: url,
);
// 6. 评估
// 6. 评估(含历史一致性)
final history = await _db.getSongsByArtist(normalized.artist, limit: 10);
final candidate = _normalizer.evaluate(normalized, history);
final finalMetadata = _normalizer.decide(candidate);
debugPrint(
'📢 [MetadataService] finalMetadata.artwork is ${finalMetadata.artwork != null ? 'not null (${finalMetadata.artwork!.length} bytes)' : 'null'}');
// 7. 保存封面图到本地
String? artworkPath;
if (finalMetadata.artwork != null && finalMetadata.artwork!.isNotEmpty) {
// 7. 与已有记录合并
final prevConfidence = (dbSong?['confidence'] as num?)?.toDouble() ?? 0.0;
final validationCount = ((dbSong?['validation_count'] as int?) ?? 0) + 1;
final useNew = dbSong == null || candidate.confidence >= prevConfidence;
final effectiveConfidence =
useNew ? candidate.confidence : prevConfidence;
// 8. 保存封面图(只有采用新结果且确实读到图时才写)
String? artworkPath = dbSong?['artwork_path'] as String?;
if (useNew &&
finalMetadata.artwork != null &&
finalMetadata.artwork!.isNotEmpty) {
artworkPath =
await ArtworkHelper.saveArtwork(finalMetadata.artwork!, songKey);
}
// 8. 保存到 SQLite
// 注意:remote_path 必须存「应用内的歌曲路径」(即 fileId / song.id),
// 不能存完整 URL。playback_controller 与 AudioService 都是用相对路径
// 调 getSongByPath() 的,存 URL 会导致永远查不到、元数据看起来“没吃上”。
await _db.insertSong({
final status =
(effectiveConfidence >= 0.6 && validationCount >= 2) ? 'verified' : 'pending';
final row = <String, dynamic>{
'song_key': songKey,
// remote_path 必须存应用内路径(fileId / song.id),不能存完整 URL
'remote_path': fileId,
'file_size': stat.size,
'modified_time': stat.modified.millisecondsSinceEpoch,
'title': finalMetadata.title,
'artist': finalMetadata.artist,
'album': finalMetadata.album,
'genre': finalMetadata.genre,
'title': useNew ? finalMetadata.title : (dbSong?['title'] ?? finalMetadata.title),
'artist':
useNew ? finalMetadata.artist : (dbSong?['artist'] ?? finalMetadata.artist),
'album': useNew ? finalMetadata.album : (dbSong?['album'] ?? finalMetadata.album),
'genre': useNew ? finalMetadata.genre : (dbSong?['genre'] ?? finalMetadata.genre),
'artwork_path': artworkPath,
'confidence': candidate.confidence,
'validation_count': 1,
'first_scan': DateTime.now().millisecondsSinceEpoch,
'confidence': effectiveConfidence,
'validation_count': validationCount,
'first_scan':
dbSong?['first_scan'] ?? DateTime.now().millisecondsSinceEpoch,
'last_scan': DateTime.now().millisecondsSinceEpoch,
'metadata_status': candidate.confidence >= 0.6 ? 'verified' : 'pending',
});
'metadata_status': status,
};
if (dbSong == null) {
await _db.insertSong(row);
} else {
await _db.updateSong(songKey, row);
}
final merged = FinalMetadata(
title: row['title'] as String? ?? '',
artist: row['artist'] as String? ?? '',
album: row['album'] as String? ?? '',
genre: row['genre'] as String? ?? '',
genres: finalMetadata.genres,
performers: finalMetadata.performers,
year: finalMetadata.year,
duration: finalMetadata.duration,
artwork: finalMetadata.artwork,
source: status,
);
// 9. 内存缓存
await _memoryCache.put(fileId, finalMetadata);
await _memoryCache.put(fileId, merged);
debugPrint(
'✅ [MetadataService] saved: ${finalMetadata.title} - ${finalMetadata.artist} (confidence: ${candidate.confidence})');
return finalMetadata;
debugPrint('📊 [MetadataService] $status '
'conf=${effectiveConfidence.toStringAsFixed(2)} '
'validations=$validationCount '
'evidence=${candidate.evidence}');
debugPrint('✅ [MetadataService] saved: ${merged.title} - ${merged.artist}');
return merged;
}
FinalMetadata _fallbackFromFileName(String fileName) {
+140
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@@ -0,0 +1,140 @@
// test/metadata_normalizer_test.dart
import 'package:flutter_test/flutter_test.dart';
import 'package:qingting_player/metadata/metadata_model.dart';
import 'package:qingting_player/metadata/metadata_normalizer.dart';
void main() {
final normalizer = MetadataNormalizer();
RawMetadata raw({
String title = '',
String artist = '',
String album = '',
int year = 0,
}) =>
RawMetadata(title: title, artist: artist, album: album, year: year);
group('normalize 字段来源', () {
test('标签齐全时三个字段都标记为来自标签', () {
final n = normalizer.normalize(
raw(title: '夜曲', artist: '周杰伦', album: '十一月的萧邦'),
fileName: 'track01.mp3',
filePath: '/音乐/周杰伦/track01.mp3',
);
expect(n.title, '夜曲');
expect(n.artist, '周杰伦');
expect(n.album, '十一月的萧邦');
expect(n.titleFromTag, isTrue);
expect(n.artistFromTag, isTrue);
expect(n.albumFromTag, isTrue);
});
test('没有标签时回退到文件名与目录', () {
final n = normalizer.normalize(
raw(),
fileName: '晴天.mp3',
filePath: '/音乐/周杰伦/晴天.mp3',
);
expect(n.title, '晴天');
expect(n.artist, '周杰伦');
expect(n.titleFromTag, isFalse);
expect(n.artistFromTag, isFalse);
});
});
group('evaluate 置信度分级', () {
NormalizedMetadata norm({
required String title,
required String artist,
String album = '',
bool titleTag = true,
bool artistTag = true,
bool albumTag = false,
}) =>
NormalizedMetadata(
title: title,
artist: artist,
album: album,
titleFromTag: titleTag,
artistFromTag: artistTag,
albumFromTag: albumTag,
);
test('标题 + 艺术家 + 专辑 → 0.90', () {
final c = normalizer.evaluate(
norm(title: '夜曲', artist: '周杰伦', album: '十一月的萧邦', albumTag: true),
const [],
);
expect(c.confidence, closeTo(0.90, 0.001));
});
test('只有标题和艺术家 → 0.80', () {
final c = normalizer.evaluate(norm(title: '夜曲', artist: '周杰伦'), const []);
expect(c.confidence, closeTo(0.80, 0.001));
});
test('只有文件名(无标签)→ 0.35,低于阈值', () {
final c = normalizer.evaluate(
norm(title: 'track01', artist: '未知艺术家', titleTag: false, artistTag: false),
const [],
);
expect(c.confidence, closeTo(0.35, 0.001));
expect(c.confidence < 0.6, isTrue);
});
test('历史一致性加权:同艺人 ≥2 条 → +0.05', () {
final history = [
{'artist': '周杰伦', 'album': ''},
{'artist': '周杰伦', 'album': ''},
];
final c = normalizer.evaluate(
norm(title: '夜曲', artist: '周杰伦'),
history,
);
expect(c.confidence, closeTo(0.85, 0.001));
expect(c.evidence['artist_history'], 0.05);
});
test('证据可解释:每一项加分都有记录', () {
final c = normalizer.evaluate(
norm(title: '夜曲', artist: '周杰伦', album: '十一月的萧邦', albumTag: true),
const [],
);
expect(c.evidence.containsKey('base'), isTrue);
expect(c.evidence.containsKey('title_from_tag'), isTrue);
expect(c.evidence.containsKey('artist_from_tag'), isTrue);
expect(c.evidence.containsKey('album'), isTrue);
});
});
group('decide 阈值', () {
test('高于阈值时 source=normalized', () {
final c = normalizer.evaluate(
const NormalizedMetadata(
title: '夜曲',
artist: '周杰伦',
titleFromTag: true,
artistFromTag: true,
),
const [],
);
final f = normalizer.decide(c);
expect(f.source, 'normalized');
expect(f.title, '夜曲');
});
test('低于阈值时 source=pending', () {
final c = normalizer.evaluate(
const NormalizedMetadata(
title: 'track01',
artist: '未知艺术家',
titleFromTag: false,
artistFromTag: false,
),
const [],
);
final f = normalizer.decide(c);
expect(f.source, 'pending');
});
});
}