edde746
12d9865a41
GoNotoCurrent lacks Hangul syllables, and the Android libmpv build has no fontconfig/system-font fallback, so libass could not resolve any Korean glyph and subtitles rendered as boxes. Ship a Hangul subset of GoNotoKurrent-Regular beside the default font in the extracted subtitle fonts directory; libass picks it up as fallback by glyph coverage. close #1932
66 lines
2.5 KiB
Dart
66 lines
2.5 KiB
Dart
import 'dart:io';
|
|
import 'package:flutter/services.dart';
|
|
import 'package:path/path.dart' as path;
|
|
import 'package:path_provider/path_provider.dart';
|
|
|
|
import '../utils/app_logger.dart';
|
|
|
|
/// Extracts font files from Flutter assets to the cache directory for
|
|
/// comprehensive Unicode coverage (including CJK and Hangul characters) for
|
|
/// libass subtitles.
|
|
///
|
|
/// GoNotoCurrent (the primary font) covers every common script except Korean,
|
|
/// and the Android libmpv build has no fontconfig/system-font fallback, so
|
|
/// libass can only find glyphs in this directory. The Hangul subset next to
|
|
/// it provides the missing syllables: generated from GoNotoKurrent-Regular
|
|
/// (satbyy/go-noto-universal v7.0) via fontTools.subset, keeping Hangul
|
|
/// Syllables, Jamo, compat Jamo, and common Hangul punctuation.
|
|
class SubtitleFontLoader {
|
|
static const String _fontAssetPath = 'assets/go-noto-current-regular.ttf';
|
|
static const String _fontName = 'Go Noto Current-Regular';
|
|
|
|
/// Hangul-only subset of Go Noto Kurrent-Regular (see class docs).
|
|
static const String _hangulFontAssetPath = 'assets/go-noto-kurrent-hangul.ttf';
|
|
|
|
/// Font files extracted to the subtitle fonts directory, in extraction order.
|
|
static const List<(String, String)> _fonts = [
|
|
(_fontAssetPath, 'go-noto-current-regular.ttf'),
|
|
(_hangulFontAssetPath, 'go-noto-kurrent-hangul.ttf'),
|
|
];
|
|
|
|
/// In-memory cache of the resolved font directory. The filesystem work
|
|
/// (temp dir lookup, existence checks, asset extraction) is idempotent per
|
|
/// process — caching the result skips ~20ms on every subsequent Player
|
|
/// instantiation.
|
|
static Future<String?>? _cachedFontDir;
|
|
|
|
static Future<String?> loadSubtitleFont() {
|
|
return _cachedFontDir ??= _loadSubtitleFontOnce();
|
|
}
|
|
|
|
static Future<String?> _loadSubtitleFontOnce() async {
|
|
try {
|
|
final cacheDir = await getTemporaryDirectory();
|
|
final fontDir = Directory(path.join(cacheDir.path, 'subtitle_fonts'));
|
|
|
|
if (!await fontDir.exists()) {
|
|
await fontDir.create(recursive: true);
|
|
}
|
|
|
|
for (final (assetPath, fileName) in _fonts) {
|
|
final fontFile = File(path.join(fontDir.path, fileName));
|
|
if (await fontFile.exists()) continue;
|
|
final fontData = await rootBundle.load(assetPath);
|
|
await fontFile.writeAsBytes(fontData.buffer.asUint8List());
|
|
}
|
|
|
|
return fontDir.path;
|
|
} catch (e, st) {
|
|
appLogger.w('Failed to load subtitle font', error: e, stackTrace: st);
|
|
return null;
|
|
}
|
|
}
|
|
|
|
static String get fontName => _fontName;
|
|
}
|