A lightweight and efficient mechanism for fixing the synchronization of misaligned subtitle documents

Abstract

Online subtitle databases allow users to easily find subtitle documents in multiple languages for thousands of films and TV series episodes. However, getting the subtitle document that gives satisfactory synchronization on the first attempt is like hitting the jackpot. The truth is that this process often involves a lot of trialand- error because multiple versions of subtitle documents have distinct synchronization references, given that they are targeted at variations of the same audiovisual content. Building on our previous efforts to address this problem, in this paper we formalize and validate a two-phase subtitle synchronization framework. The benefit over current approaches lays in the usage of audio fingerprint annotations generated from the base audio signal as second-level synchronization anchors. This way, we allow the media player to dynamically fix during playback the most common cases of subtitle synchronization misalignment that compromise users' watching experience. Results from our evaluation process indicate that our framework has minimal impact on existing subtitle documents and formats as well as on the playback performance.