Aligning video to audio

When you import a video, LTCast automatically aligns it by comparing the video's internal audio track to the loaded song using waveform matching. The result is an offset that tells LTCast where the video start sits relative to the audio.

Auto-alignment

Auto-alignment runs right after import. LTCast slides the video's audio against the song's waveform, looking for the best-matching position. When the match is good, the offset is applied. When it is not, LTCast places the video at 0:00 and says Audio does not match the video well — placed at 0:00; that happens when the video's audio and the song share too little content. In that case, align it by hand.

If the video is longer than the song, auto-alignment is skipped to keep loading fast. The video is placed at 0:00, with the message Video is longer than the song — auto-align skipped for fast load. Set the start point manually.

To run the comparison again, click the ⟳ button (Re-sync to audio) in the Video Audio row.

Seeing and setting the alignment

There is no comparison dialog after import. The alignment is shown in the green Video Audio lane under the music waveform: the video's audio sits against the music, so you can see whether the loud moments line up. When the song contains LTC, the lane header shows Start TC, the timecode at the point where the video starts. The offset itself is shown as a small number such as +1.20s at the bottom of the Video Reference panel; it is a display, not a field you can type into.

To align by hand, drag the Video Audio lane left or right until its waveform lines up with the music above it. Each drag is one step of Ctrl+Z.

Frame nudge

For precision fine-tuning after auto-align or manual adjustment, use the ◀ and ▶ buttons in the Video Audio row. See Frame nudge for details. The offset changes by exactly one frame per press, at the project's current frame rate.