Electric Network Frequency (ENF) continuously fluctuates around a nominal value (50/60 Hz) due to a persistent imbalance between supplied and demanded power. In certain circumstances, ENF gets intrinsically embedded into audio and video recordings and can be extracted from these recordings. Consequently, ENF can be used in a number of media forensic applications, such as verifying the time of recording of the media. In this work, a robust media time-stamping approach is proposed for media whose ENF content is relatively contaminated. It essentially entails two procedures: first, detecting all useful, i.e., considerably accurate, samples of an estimated ENF signal, and then applying an adapted normalized cross-correlation process that is designed for exploiting just the selected ENF portions based on a binary mask of the identified accurate samples. Experimental results show that the proposed approach provides significantly increased performance.

中文翻译：

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基于 ENF 的鲁棒媒体时间戳

由于电力供应和需求之间的持续不平衡，电网频率 (ENF) 在标称值 (50/60 Hz) 附近持续波动。在某些情况下，ENF 本质上嵌入到音频和视频记录中，并且可以从这些记录中提取。因此，ENF 可用于许多媒体取证应用程序，例如验证媒体的记录时间。在这项工作中，针对 ENF 内容相对受污染的媒体，提出了一种强大的媒体时间戳方法。它本质上需要两个过程：首先，检测估计的 ENF 信号的所有有用的，即相当准确的样本，然后应用经过调整的归一化互相关过程，该过程旨在仅利用基于二进制掩码的选定 ENF 部分确定的准确样本。