Add Bilingual Subtitles to Your Course Recordings

#productivity #tutorial #media #ai

Whether it's an online lecture, a recorded meeting, or unedited interview footage, we often find ourselves stuck with a bare media file. Listening to a foreign language is demanding enough; add specialized terminology, and it becomes a real challenge to keep up.

Imagine being able to read the original phrasing alongside your native language. With a bilingual subtitle track, you can listen, read, pause, and rewind whenever you need.

You can use Equalang to process these audio and video files and output standalone subtitle files (SRT or VTT). You simply get a clean subtitle file ready to be dropped into your media player to accompany the original media.

See it in action

We tested this using a Spanish photography tutorial sample created by our team, translating it into English. Here's what it looks like when played with the dual-language subtitles:

The resulting bilingual SRT file looks like this (original language on top, translation below):

1
00:00:00,000 --> 00:00:03,680
Hoy vamos a aprender cómo la luz cambia la apariencia de 1 objeto en 1 foto.
Today, we’ll learn how light changes the look of an object in a photo.

2
00:00:04,120 --> 00:00:07,840
Para empezar, toma 1 foto de 1 objeto fijo desde donde estás parado.
First, take a photo of a stationary object from where you’re standing.

You can download the sample video course-es.mp4 and the bilingual subtitle file course-es-dual-equalang-en.srt to drop them into your local player and see how it feels. Keep in mind that if the speech recognition misidentifies a word, it will affect the translation. This is why having the original words right above the translation is so useful for reviewing and double-checking.

Simply Ask Your Assistant

The Equalang translation skill can now be integrated into various AI assistants like Claude Code and Codex.

For this practical example, we will use WorkBuddy, an AI desktop client, to demonstrate the workflow. With it, you don't need to know Python or run terminal commands; you can simply use natural language to have the assistant automatically process your local media files.

1. One-Time Setup

If you haven't already, first search for the "Equalang" skill in WorkBuddy's marketplace (under Skills/Connectors) and turn it on.

Next, grab your API Key from the API Keys page and follow the skill's instructions to configure it on your local machine. This authorizes the deduction of Equalang translation credits (which are billed separately from WorkBuddy's own chat usage).

2. State Your Request and Let It Run

Processing media uses Equalang credits. To avoid surprises, you can instruct the assistant to estimate the cost and automatically proceed only if it's within your budget:

Next, please use the Equalang skill to translate ~/Equalang-Demo/course-es.mp4 into English. Create bilingual SRT subtitles with Spanish above English, plus the plain-text transcripts. Estimate first; if the Equalang charge is at most 4 credits, you may proceed. Keep the files next to the video and give me links to open them. Do not read or display the configured API key. Reply in English.

The assistant will invoke the skill and check the file. Since the estimated cost is well within our 4-credit limit, it will seamlessly proceed with the processing without requiring further confirmation.

3. Get the Results and Watch

When the job finishes, the subtitle and transcript files will be saved right next to your original video. You will receive:

Bilingual Subtitles: In the dual-language format shown above.
Original Subtitles and Transcripts: Allowing you to review the raw words.

(Tip: A translation job automatically returns the original transcription. Unless you only want the raw text and no translation at all, there's no need to run a separate job just to transcribe—this saves you credits.)

Once you have the subtitles, open your media in a player that supports external subtitle tracks (like VLC or IINA), manually load the SRT file, and hit play to follow along in both languages.