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TechPoint-VideoCaptions-Code
Hey everyone! In my last video, I showed you how to generate and overlay captions on your videos for FREE, without spending money on expensive captioning tools. A lot of you loved it! But some of you reached out and asked for a deeper dive into the code—how it works behind the scenes.
So in this video, I’m going to break it down for you—step by step. We’ll go through the Python script that extracts captions, the HTML, JavaScript, and CSS that overlay captions on videos, and the Flask backend that manages everything. By the end, you’ll fully understand how this tool works, and you’ll be able to customize it for your own projects!
Let's break it down! Code walkthrough coming up!
Step 1: Extracting Captions.
Alright, let’s start with the first part—extracting captions from a video file. This is handled by our Python script, caption_generator.py. Let’s go through the code.
Extracts audio from the input video (input_video.mp4).
Uses Whisper AI to transcribe the speech and get word timestamps.
After running the script, we get a JSON file that contains every word along with its start and end timestamps. This file will be used to perfectly sync captions with the video.
Step 2: Overlaying Captions on Video
Now that we have our captions, let’s move to the front-end where we overlay them on a video. This happens in our index.html and script.js.
The captions appear dynamically below the video, and we can select different styles from this dropdown. But how does it work? That’s where our script.js comes in.
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This script listens to the video’s current timestamp and updates the caption accordingly. It also lets us choose different styles dynamically.
Step 3: Running the Backend Server
Now, let’s talk about the backend—the part that serves our captions. We use a simple Flask server for this.
The frontend fetches captions from this backend using an API call. If we ever want to modify or edit captions, we can update them in the JSON file and reload.
Alright, now that we understand how it all works, let’s put everything together!
Now, you can use this tool for your own videos and even customize it further. Want different fonts, colors, or animations? Just modify styles.css. Want to add more features? You now know exactly how the code works!
That’s it for this tutorial! Now you understand how this free captioning tool works, from start to finish. If you found this helpful, hit that like button and subscribe for more coding tutorials!
And if you want to take this even further, drop a comment below! What features should we add next? Let me know, and I might cover them in the next video!