You recorded a clip on a phone and it is a 3GP file; you want SRT and VTT subtitles from it. Send it to Potok in Telegram, then download both subtitle files. Players differ in how they read built-in text, so load the SRT as a separate file and play 1 scene to check it.
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.
Open @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
- 3GP is used by MMS, PSS and MBMS services.
- RFC 3839 says video/3gpp is valid for all 3GP files.
- 3GPP TS 26.245 defines the timed text format used by 3GP; tx3g is its sample entry, so a 3GP can carry timed text.
- Potok accepts .3gp files up to 2 GB and reads them without a conversion step.
3GP at a glance
| Property | Value |
|---|---|
| Kind | Container for mobile phones (3GPP) |
| Media types | video/3gpp, audio/3gpp |
| What it holds | An instance of the ISO base media file format defined by 3GPP TS 26.244 |
How to make subtitles from 3GP files
- Upload the .3gp file. Start a chat with @potok_now_bot and upload the 3GP file. Each file may be up to 2 GB, and the Upload button in the mini app handles the largest ones.
- One property of the format matters. 3GPP TS 26.245 defines the timed text format used by 3GP; tx3g is its sample entry, so a 3GP can carry timed text.
- Export SRT or VTT. Choose SRT or VTT among the export buttons and load the file next to the video in your editor or player; check the first and the last caption against the sound.
- Good to know. RFC 3839 says video/3gpp is valid for all 3GP files.
What the subtitle file looks like
[00:00:01,000 --> 00:00:03,400] Caption 1: We just arrived at the old harbor market.
[00:00:03,600 --> 00:00:06,100] Caption 2: The fish stalls open before sunrise here.
[00:00:06,300 --> 00:00:09,000] Caption 3: Let's find a place for breakfast nearby.
[00:00:09,200 --> 00:00:11,800] Caption 4: I forgot my umbrella on the bus again this morning.
Captions written by us to show the layout. They are not output from a real 3GP file.
| Option | What it means |
|---|---|
| Accepted | Voice messages, audio and video |
| Digest | Press the summary button under a finished transcript for a short digest |
| Dictation | For dictating into other programs there is a separate Potok desktop app that recognises Russian speech |
| Recognition | About 30 languages with good published results; a few more with warnings |
| Size limit | Files up to 2 GB |
Typical 3GP slips
| What goes wrong | Effect | What to do |
|---|---|---|
| Assuming timed text in a 3GP works in every player | Many players ignore tx3g text and show no captions | Use a separate SRT or VTT file for sharing |
| Sending a very short 3GP clip with mostly noise | Captions are mostly empty or contain wrong words | Send the 3GP clip that includes clear speech |
| Renaming the .3gp to .mp4 to make subtitles appear | The container is unchanged and the captions still do not show | Load the SRT or VTT file in the player |
| Sending a 3GP clip recorded with the phone speaker covered | Muffled words give gaps and guessed words in captions | Record with the microphone uncovered, or re-check unclear captions |
More
The tools section has converters and calculators, the glossary explains the terms, and the download page covers the apps.
Frequently asked questions
Is 3GP supported?
It is: the bot takes .3gp files of up to 2 GB and decodes them itself, so you do not need to convert anything first.
Will the captions be burned into my 3GP file?
No. You get a separate .srt or .vtt text file, and your original 3GP file stays unchanged.
Which apps and devices create 3GP files?
Android MediaRecorder offers a THREE_GPP output format (Android MediaRecorder THREE_GPP).
Sources
We opened each page below on the date shown. Because pages get updated, confirm important details at the source.
Try it on your own recording
Drop an audio or video file, or a voice message, into the chat with @potok_now_bot; the recognized text is sent back there.
Open @potok_now_bot in Telegram