Make SRT and VTT subtitles from Opus files by sending 1 file to Potok in Telegram; both subtitle files come back as downloads. The audio holds no caption text, so they always arrive separately, and a very long call is safer sent in parts. Open the SRT afterwards and compare its first and last lines with the audio.
Turn a recording into text
Open @potok_now_bot in Telegram, attach the recording and wait: the transcript arrives as a message in the same chat.
Go to @potok_now_bot in Telegram
Files up to 2 GB · export to TXT, MD, DOCX, PDF, SRT and VTT · speaker labels and timestamps · about 30 languages
Key facts
- Opus supports bitrates from 6 kbit/s to 510 kbit/s.
- RFC 7845 defines the Ogg encapsulation for the Opus codec.
- Ogg Opus (RFC 7845) is an audio stream with no subtitle track (audio only), so an SRT stays a separate file.
- Potok accepts .opus files up to 2 GB and reads them without a conversion step.
About the Opus format
| Property | Value |
|---|---|
| Kind | Audio codec, stored in Ogg as .opus |
| Media types | audio/ogg |
| What it holds | The Opus codec in an Ogg encapsulation |
How to make subtitles from Opus files
- Start with the bot. Go to @potok_now_bot in Telegram, then send your .opus recording. The limit is 2 GB per file, and the Upload button of the mini app is the way to send a big one.
- One property of the format matters. Ogg Opus (RFC 7845) is an audio stream with no subtitle track (audio only), so an SRT stays a separate file.
- Get the subtitle file. Press the SRT or VTT export button; each caption carries a start and an end time. Then attach the file to the video and check how it lines up.
- Good to know. RFC 7845 defines the Ogg encapsulation for the Opus codec.
What the subtitle file looks like
[00:00:01,000 --> 00:00:03,400] Caption 1: Hi, I'm calling about the delivery from Monday.
[00:00:03,600 --> 00:00:06,100] Caption 2: The package arrived, but the box was damaged.
[00:00:06,300 --> 00:00:09,000] Caption 3: I can send you a photo right now.
[00:00:09,200 --> 00:00:11,800] Caption 4: My grandmother's soup recipe needs plenty of time and patience.
Captions written by us to show the layout. They are not output from a real Opus file.
| Feature | Details |
|---|---|
| Export | TXT, MD, DOCX and PDF for text; SRT and VTT for subtitles |
| What you can send | Voice messages, audio files and video files |
| Languages | About 30 languages with good published results and a few more with warnings |
| Speakers | You can turn on speaker labels and timestamps |
| Dictation | A separate Potok desktop app lets you dictate text into any program; it recognises Russian speech |
What to avoid with Opus
| Slip | Result | Remedy |
|---|---|---|
| Expecting an Opus file to hold subtitle text | Nothing appears on screen because Ogg Opus is audio only | Keep the SRT as a separate file beside the audio |
| Changing the .opus extension to .srt by hand | The file stays audio and no player can read it | Download the real SRT file from the bot chat |
| Sending a long Opus call as one unbroken recording | Captions become one long list that is hard to edit | Split the Opus file by topic before sending |
| Judging the subtitles by the first minute only | Errors in later parts stay unnoticed until viewers complain | Skim the middle and the ending of the SRT too |
Where to look next
Need a converter or a calculator? Open the tools. Unsure about a term? Check the glossary. Apps are on the download page.
Frequently asked questions
Is Opus supported?
It is: the bot takes .opus files of up to 2 GB and decodes them itself, so you do not need to convert anything first.
What is the difference between SRT and VTT?
SRT is a plain list of numbered captions with start and end times. VTT starts with a WEBVTT header and is the format web video players read.
Which apps and devices create Opus files?
Telegram sendVoice takes audio in an OGG file encoded with Opus (Telegram sendVoice input).
Sources
Each source was opened by hand on the date shown. Pages change, so open the source if a detail matters to you.
- RFC 7845: Ogg encapsulation for the Opus audio codec, IETF · checked
- RFC 6716: Definition of the Opus audio codec, IETF · checked
Run your own recording through it
Send your voice message, audio or video to @potok_now_bot on Telegram and the text comes back in the chat.
Write to @potok_now_bot in Telegram