Video AI Tools
Lesson 5.3 — Video AI
Video content dominates the internet, but creating it has always required a combination of technical skills, expensive software, and significant time. AI is dismantling each of those barriers. You can now caption a video automatically, repurpose a long interview into a dozen short clips, remove filler words with a click, and — at the cutting edge — generate video from text entirely.
This lesson covers the full spectrum: practical tools you can use today for captions and editing, tools for content repurposing, an overview of generative video, and a complete creator workflow that ties it all together.
Auto-Captions: The Simplest Win
If you produce any video content at all — for social media, business presentations, training, or personal projects — automatic captions are the single easiest quality improvement available.
Why captions matter:
- 85% of Facebook videos are watched without sound
- Captions increase watch time and accessibility
- They are now expected on most platforms
Tools for auto-captioning:
CapCut, a free video editor available on mobile and desktop, has built-in auto-caption that is remarkably accurate. Here is the process:
- Import your video into CapCut
- Tap "Text" → "Auto Captions"
- Select the language and click Generate
- CapCut transcribes the audio and places captions as text layers on the timeline
- Review for errors — names and technical terms most commonly need correction
- Style the captions: font, size, colour, position, animation style
- Export
The whole process from import to export takes about 10–15 minutes for a 5-minute video. Without AI, caption editing used to take an hour or more.
Other captioning tools:
- Descript — captions via editing the transcript text; excellent for longer-form video
- Submagic — specifically designed for short-form social content, with animated captions that match current trends
- Adobe Premiere Pro — built-in AI transcription and captions via Speech to Text feature
- YouTube — auto-generates captions for uploaded content; edit them in YouTube Studio
CapCut AI: More Than Captions
CapCut has expanded significantly beyond basic editing. Its AI features include:
- Background remover — removes background from video without a green screen
- Smart cutout — isolates a subject from the background in a clip
- AI voice — generates voiceover from text using synthetic voices
- Beat sync — automatically matches cuts to music rhythm
- Reframe — automatically reformats horizontal video for vertical (9:16) formats for TikTok/Reels
- Text-based editing — edit video by editing the transcript
For social media creators, CapCut has become a one-stop shop for production. The mobile app is free with generous features; the desktop version is also free with optional paid upgrades.
Key takeaway: CapCut is the most accessible entry point for AI video editing. If you are just starting out with video content, learn CapCut before anything else.
Opus Clip: Repurposing Long Videos into Short Clips
One of the biggest challenges for content creators is the amount of time required to produce different formats from the same source material. A 45-minute podcast interview could become twenty 60-second clips for TikTok and Instagram Reels — but manually watching, selecting, cutting, and captioning each clip used to take an entire day.
Opus Clip automates this process.
How it works:
- Upload a long video or paste a YouTube URL
- Opus Clip analyses the content — identifying the most engaging moments using AI trained on what drives watch time and retention
- It selects 10–15 clips, adds captions, and formats them vertically for social media
- You review, edit, and download the clips you want to use
The result: A 60-minute video produces a week's worth of social content in about 30 minutes of your time, versus several hours manually.
What it does well: Identifying punchy standalone moments, moments with a clear hook and payoff, and segments with natural emphasis or emotion.
Limitations: It does not understand nuance or context — a clip might look engaging but be misleading out of context. Always review what it selects before publishing. It also works much better on talking-head content than on highly visual or heavily edited video.
Cost: Free tier allows limited clips per month. Paid plans from around $15/month.
Runway: AI Video Generation
Runway represents the frontier of what AI can do with video. It is not primarily an editing tool — it is a generative tool, capable of creating video from text prompts, animating still images, and applying dramatic visual effects.
Key capabilities:
- Text-to-video (Gen-3): Describe a scene in text, receive a short video clip
- Image-to-video: Upload a still image and Runway animates it
- Inpainting: Replace part of a video frame with AI-generated content
- Motion brush: Animate specific areas of an image
- Background removal from video
Practical reality check: Text-to-video AI is impressive but still has significant limitations. Clips are short (typically 4–10 seconds), motion can be strange, and outputs sometimes contain obvious artefacts. It is excellent for abstract visuals, mood-setting clips, and concept visualisation — less reliable for realistic human-led footage.
Other generative video tools: Pika Labs, Stable Video Diffusion, and Sora (OpenAI, limited access) are competitors in this space. The capabilities are advancing extremely rapidly; expect significant improvements in the 12 months following this course.
A Complete Creator Workflow
Here is how these tools combine into a practical workflow for someone producing regular content — say, a weekly long-form interview video plus social clips:
Step 1 — Record Record your interview or presentation. If recording remotely, use Riverside.fm for high-quality separate audio and video tracks.
Step 2 — Transcribe Upload to Descript or Otter.ai. Clean the transcript — this also serves as your editing script.
Step 3 — Edit the main video In Descript, edit the transcript (cut filler words, mistakes, and off-topic tangents). The video edits automatically to match. Export the main video.
Step 4 — Generate clips Upload the main video to Opus Clip. Review the clips it suggests. Download the best 5–10.
Step 5 — Caption and style Open clips in CapCut. Apply animated captions, adjust styling to match your brand, add intro and outro.
Step 6 — Write descriptions Use ChatGPT or Claude: "Write three variations of a YouTube description for a video about [topic]. Include a hook in the first line, key timestamps, and a call to action. Also write a short caption for Instagram and a caption for LinkedIn."
Step 7 — Schedule and publish Upload to YouTube, schedule Reels/TikTok posts through a scheduler like Buffer or Later.
Total additional time from AI tools compared to manual: A workflow that might take 8–10 hours can be completed in 2–3 hours with these tools integrated.
What AI Cannot Do (Yet)
| Task | Current AI status |
|---|---|
| Complex narrative editing | Human judgment still required |
| Directing and shot selection during recording | Human only |
| Brand-specific colour grading | Can assist but needs human eye |
| Long-form coherent story generation | Short clips only |
| Reliable photorealistic human video from text | Rapidly improving, not yet reliable |
Practice Task
If you have an existing video — even a personal one on your phone — import it into CapCut and use the auto-caption feature. Style the captions to something you like, then export. This is the simplest possible introduction to AI video tools and takes less than 20 minutes from start to finish.