Add teaser subtitles to an existing SRT with Aegisub

Adding new teaser subtitle lines to an existing .SRT is one of those small edits that can get frustrating, especially when you’ve already got a perfect subtitle file for the full video. The good news: in Aegisub, the quickest method is often a simple copy/paste workflow, plus a timing shift.

Background

When posting an interview, it’s often smart to start the video with a teaser. A small part (around 30 seconds) of the full video copied to the front of the video, so people are tempted to watch the whole video. It’s a short, punchy preview, a strong hook.

Subtitles are generated for the full interview, and copying part of the video to the front breaks the timing. Simply shifting everything forward fixes the main video, but leaves the teaser itself without subtitles. And that’s not what I want.

So, here’s what I did to solve this.

Steps to follow

Here’s what you need to do to edit the .SRT file and add subtitles for the teaser, and make sure the timing is shifted for the full video.

Step 1: Open your full SRT in Aegisub

• Open Aegisub.
• Go to File → Open subtitles, and load your full video .SRT.
• Optional: Open your full video (including the teaser): Video → Open video
• Select the lines of the full video subtitles you need for the teaser
• Copy the selected lines

Step 2: Fix the timing

• Check the length of the teaser video (subtract the start time from the end time)
• Go to Timing → Shift Times
• Enter the time in the “Shift by” section
• Select Forward
• Select All rows
• Select Start and End times
• Press OK

You’ve now made room for the teaser subtitles in front of the full subtitles.

Step 3: Paste the teaser subtitles

• Select the first line in the Aegisub editor
• Paste the copied lines

Now the subtitles have the teaser subtitles in front, but the timing is off.

Step 4: Adjust the teaser subtitle timing

• Select the teaser subtitle lines you have just pasted
• Use the same timing as used in step 2, but now select Backward
• Select Selected rows
• Press OK

And we’re done. We added the teaser subtitles and adjusted the timing. Now it’s time to export the SRT through File → Export subtitles and make sure to use “.srt” as file extension.

Test the subtitles by opening up the full video (including the teaser) and load the .SRT file we just exported.

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