import 'dart:typed_data';

/// SPS/PPS/I帧依赖关系管理器
class FrameDependencyManager {
  Uint8List? _sps;
  Uint8List? _pps;
  int? _lastIFrameSeq;

  /// 更新SPS缓存
  void updateSps(Uint8List sps) {
    _sps = sps;
  }
  /// 更新PPS缓存
  void updatePps(Uint8List pps) {
    _pps = pps;
  }
  Uint8List? get sps => _sps;
  Uint8List? get pps => _pps;

  /// 判断是否有可用I帧
  bool get hasIFrame => _lastIFrameSeq != null;
  int? get lastIFrameSeq => _lastIFrameSeq;
  void updateIFrameSeq(int seq) {
    _lastIFrameSeq = seq;
  }

  /// 判断指定I帧序号是否为最近一次成功解码的I帧
  bool isIFrameDecoded(int? seq) {
    return seq != null && seq == _lastIFrameSeq;
  }
}