Init repo

lib/models/trickplayer_model.dart

@@ -0,0 +1,177 @@
+// ignore_for_file: public_member_api_docs, sort_constructors_first
+import 'dart:convert';
+
+import 'package:flutter/foundation.dart';
+
+import 'package:fladder/models/items/chapters_model.dart';
+
+class Bif {
+  final String version;
+  final List<int> widthResolutions;
+  Bif({
+    required this.version,
+    required this.widthResolutions,
+  });
+
+  Bif copyWith({
+    String? version,
+    List<int>? widthResolutions,
+  }) {
+    return Bif(
+      version: version ?? this.version,
+      widthResolutions: widthResolutions ?? this.widthResolutions,
+    );
+  }
+
+  Map<String, dynamic> toMap() {
+    return <String, dynamic>{
+      'Version': version,
+      'WidthResolutions': widthResolutions,
+    };
+  }
+
+  factory Bif.fromMap(Map<String, dynamic> map) {
+    return Bif(
+      version: (map['Version'] ?? '') as String,
+      widthResolutions: List<int>.from((map['WidthResolutions'] ?? const <int>[]) as List<dynamic>),
+    );
+  }
+
+  String toJson() => json.encode(toMap());
+
+  factory Bif.fromJson(String source) => Bif.fromMap(json.decode(source) as Map<String, dynamic>);
+
+  @override
+  String toString() => 'Bif(version: $version, widthResolutions: $widthResolutions)';
+
+  @override
+  bool operator ==(covariant Bif other) {
+    if (identical(this, other)) return true;
+
+    return other.version == version && listEquals(other.widthResolutions, widthResolutions);
+  }
+
+  @override
+  int get hashCode => version.hashCode ^ widthResolutions.hashCode;
+}
+
+class BifUtil {
+  static List<int> bifMagicNumbers = [0x89, 0x42, 0x49, 0x46, 0x0D, 0x0A, 0x1A, 0x0A];
+  static const int supportedBifVersion = 0;
+
+  static Future<BifData?> trickPlayDecode(Uint8List array, int width) async {
+    Indexed8Array data = Indexed8Array(array);
+
+    for (int b in bifMagicNumbers) {
+      if (data.read() != b) {
+        print('Attempted to read invalid bif file.');
+        return null;
+      }
+    }
+
+    int bifVersion = data.readInt32();
+    if (bifVersion != supportedBifVersion) {
+      print('Client only supports BIF v$supportedBifVersion but file is v$bifVersion');
+      return null;
+    }
+
+    print('BIF version: $bifVersion');
+
+    int bifImgCount = data.readInt32();
+    if (bifImgCount <= 0) {
+      print('BIF file contains no images.');
+      return null;
+    }
+
+    print('BIF image count: $bifImgCount');
+
+    int timestampMultiplier = data.readInt32();
+    if (timestampMultiplier == 0) timestampMultiplier = 1000;
+
+    data.addPosition(44); // Reserved
+
+    List<BifIndexEntry> bifIndex = [];
+    for (int i = 0; i < bifImgCount; i++) {
+      bifIndex.add(BifIndexEntry(data.readInt32(), data.readInt32()));
+    }
+
+    List<Chapter> bifImages = [];
+    for (int i = 0; i < bifIndex.length; i++) {
+      BifIndexEntry indexEntry = bifIndex[i];
+      int timestamp = indexEntry.timestamp;
+      int offset = indexEntry.offset;
+      int nextOffset = i + 1 < bifIndex.length ? bifIndex[i + 1].offset : data.limit();
+
+      Uint8List imageBytes = Uint8List.sublistView(Uint8List.view(data.array.buffer, offset, nextOffset - offset));
+
+      bifImages.add(
+        Chapter(
+          name: "",
+          imageUrl: "",
+          imageData: imageBytes,
+          startPosition: Duration(milliseconds: timestamp * timestampMultiplier),
+        ),
+      );
+    }
+    return BifData(bifVersion, bifImgCount, bifImages, width);
+  }
+}
+
+class Indexed8Array {
+  Uint8List array;
+  int readIndex;
+
+  Indexed8Array(Uint8List byteArray)
+      : array = byteArray,
+        readIndex = 0;
+
+  int read() {
+    return array[readIndex++];
+  }
+
+  void addPosition(int amount) {
+    readIndex += amount;
+  }
+
+  int readInt32() {
+    int b1 = read() & 0xFF;
+    int b2 = read() & 0xFF;
+    int b3 = read() & 0xFF;
+    int b4 = read() & 0xFF;
+
+    return b1 | (b2 << 8) | (b3 << 16) | (b4 << 24);
+  }
+
+  Uint8List getByteArray() {
+    return array;
+  }
+
+  int limit() {
+    return array.length;
+  }
+
+  Endian order() {
+    return Endian.big;
+  }
+}
+
+class BifIndexEntry {
+  int timestamp;
+  int offset;
+
+  BifIndexEntry(this.timestamp, this.offset);
+}
+
+class BifData {
+  int bifVersion;
+  int bifImgCount;
+  List<Chapter> chapters;
+  int width;
+
+  BifData(
+    this.bifVersion,
+    this.bifImgCount,
+    this.chapters,
+    this.width,
+  );
+}