Deep-Sync: A novel deep learning-based tool for semantic-aware subtitling synchronisation


Subtitles are a key element to make any media content accessible for people who suffer from hearing impairment and for elderly people, but also useful when watching TV in a noisy environment or learning new languages. Most of the time, subtitles are generated manually in advance, building a verbatim and synchronised transcription of the audio. However, in TV live broadcasts, captions are created in real time by a re-speaker with the help of a voice recognition software, which inevitability leads to delays and lack of synchronisation. In this paper, we present Deep-Sync, a tool for the alignment of subtitles with the audio-visual content. The architecture integrates a deep language representation model and a real-time voice recognition software to build a semantic-aware alignment tool that successfully aligns most of the subtitles even when there is no direct correspondence between the re-speaker and the audio content. In order to avoid any kind of censorship, Deep-Sync can be deployed directly on users’ TVs causing a small delay to perform the alignment, but avoiding to delay the signal at the broadcaster station. Deep-Sync was compared with other subtitles alignment tool, showing that our proposal is able to improve the synchronisation in all tested cases.

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This work has been supported by the Spanish Ministry of Science and Education under TIN2017-85727-C4-3-P grant (DeepBio) and Comunidad Autónoma de Madrid under S2018/TCS-4566 grant (CYNAMON). We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan V GPU used for this research.

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Correspondence to Alejandro Martín.

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The code of Deep-Sync and the instructions to be executed are available at:

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Martín, A., González-Carrasco, I., Rodriguez-Fernandez, V. et al. Deep-Sync: A novel deep learning-based tool for semantic-aware subtitling synchronisation. Neural Comput & Applic (2021).

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  • TV Broadcasting
  • Synchronisation
  • Language model
  • Deep neural networks
  • Machine learning