VietSubAI

Chapter 1

Introduction

VietSubAI is a script that runs inside DaVinci Resolve. Select a clip, press one button, and it sends the audio to AssemblyAI for transcription, then lays the words back on your timeline as Text+ captions, a few words at a time, already styled.

I built it because Vietnamese subtitling was quietly eating my evenings. Most auto-caption tools either can’t handle Vietnamese well or give you plain white text that you then restyle line by line.

The captions are normal Text+ clips. Click one and Resolve’s own Inspector opens, so animation, keyframes and effects all work as usual.

Chapter 2

What it’s for

• Talking-head videos and tutorials where every line needs a caption.
• Reels and TikToks, where captions do half the work because most people watch with the sound off.
• Vietnamese subtitles, which is where it saves the most time.
• SRT files for YouTube, exported from the same transcription.

Chapter 3

How to use it

1. Prepare a template once. Drag Effects → Titles → Text+ into your Media Pool. VietSubAI copies this item for every caption, so it has to be there.

2. Select the clip on the timeline that you want subtitled.

3. Open VietSubAI from Workspace → Scripts → VietSubAI.

4. Paste your AssemblyAI API key the first time. It’s saved on your computer for next time.

5. Choose the language (Vietnamese, English or auto detect), how many words go in each caption and which video track they go on.

6. Generate. The captions appear on the track you chose, timed to the speech.

7. Style them in the panel’s tabs: Text & Colour, Shading and Layout. The caption under the playhead updates as you change things, and Undo works.

8. Fix names by hand. Names and gear words (Osmo, Focusrite, anamorphic) sometimes come back wrong. Click the caption and edit it in the Inspector.

9. Export an SRT from the panel if you also need a subtitle file.

Chapter 4

How to install

1. Check your Resolve. VietSubAI needs DaVinci Resolve Studio 18.5 or newer.

2. Turn on scripting. Preferences → System → General → External scripting using: Local.

3. Copy VietSubAI.py into Resolve’s Utility scripts folder.

   Mac:

   ~/Library/Application Support/Blackmagic Design/DaVinci Resolve/Fusion/Scripts/Utility/

   Windows:

   %APPDATA%\Blackmagic Design\DaVinci Resolve\Support\Fusion\Scripts\Utility\

4. Restart Resolve. VietSubAI now shows under Workspace → Scripts.

5. Get an API key from your AssemblyAI dashboard.

6. Optional: install FFmpeg. VietSubAI works without it, but with FFmpeg it uploads only the audio, which is faster. On a Mac with Homebrew:

   brew install ffmpeg

VietSubAI isn’t in a public download folder yet. Message me and I’ll send you a copy.