How AI Song Video Sync Works
Sync is one of the hardest parts of turning speech into a song. The generated audio is not a simple copy of the original voice, so the video timeline has to be adapted carefully.
Original Speech Has One Timeline
In the source video, every spoken word happens at a specific moment. A transcript can capture those timings, which tells the system which part of the video corresponds to each word.
Singing Creates a New Timeline
A song changes the timing of speech. Words may be held longer, compressed into rhythm, or placed after musical pauses. That means a simple stretch of the whole video is often not enough.
Word Timing Helps Reconnect Them
Tune It Up analyzes both timelines: the original speech timing and the generated song timing. It then maps sung words back to their source words so the visual segment can follow the sung phrase more closely.
Why Some Drift Can Still Happen
AI song models do not always return exact internal lyric timing, and sung words can be harder to transcribe than normal speech. The tool uses word-level alignment to reduce drift, but users should still preview the final MP4 before posting.