Engineering Real-Time Video Pronunciation Search: Subtitle Synchronization, Syllable Stress Parsing & Phonetic Alignment

Description and use

SayItVid offers real‑time pronunciation search with synchronized video, subtitles, and visual stress markers, enhancing learning of natural speech patterns.

Problem

Traditional online dictionaries provide isolated pronunciation snippets that fail to capture natural conversational speech patterns such as elision, flapping, and connectedness, limiting learners’ ability to recognize words in real-world contexts.

Outcome

SayItVid delivers real‑time, context‑aware pronunciation search with synchronized video playback, visual stress markers, and accurate phonetic mapping, improving learners’ exposure to natural speech patterns.

Workflow

• Ingest timestamped WebVTT/subtitle tracks and parse sentence boundaries to establish word‑level temporal anchors.
• Align English lexicon tokens with CMU dictionary entries and stress indices to map phonetic and IPA data.
• Index lexical phrases using SQLite FTS5/BM25 for sub‑millisecond retrieval.
• Calculate acoustic context windows around target words to provide pre‑roll and post‑roll playback buffers.
• Render synchronized video playback with subtitle cues and visual phonetic cards in the client UI.

Evidence

Traditional online dictionaries treat pronunciation as an isolated acoustic unit. You look up a word, see a static International Phonetic Alphabet (IPA) string, and press a speaker button to play a 1.5-second pre-recorded audio snippet captured in a silent sound studio.

Source

To bridge this gap, we built SayItVid — a real-time video pronunciation search engine that indexes thousands of authentic conversational video moments and provides synchronized subtitles, IPA transcriptions, visual syllable stress markers, and word origins in under 50 milliseconds.

Source

This guarantees that when a user searches for a difficult word like literally, the video begins just before the clause starts, allowing the brain's auditory processing to calibrate to the speaker's cadence before the target word is uttered.

Source