AMR files become SRT and VTT subtitles when you send them to Potok in Telegram, and 2 files come back as downloads. AMR is a compact voice format, so quiet or distant speakers may leave gaps in the captions. Read the SRT once and fix any gap before you publish it.
Turn a recording into text
Drop an audio or video file, or a voice message, into the chat with @potok_now_bot; the recognized text is sent back there.
Go to @potok_now_bot in Telegram
Export to TXT, MD, DOCX, PDF, SRT and VTT · files up to 2 GB · about 30 languages · speakers and timestamps on request
In short
- AMR storage files begin with the magic string #!AMR followed by a newline; AMR-WB uses #!AMR-WB.
- Android lists AMR-NB in 3GPP (.3gp) and AMR (.amr) files at 4.75 to 12.2 kbps sampled at 8 kHz.
- A single-channel AMR file holds only a magic number before the speech frames (audio only), so an SRT stays a separate file.
- The bot reads .amr files of up to 2 GB directly; Potok adds no conversion step.
AMR at a glance
| Property | Value |
|---|---|
| Kind | Speech codec for mobile phones |
| Media types | audio/AMR, audio/AMR-WB |
| What it holds | Adaptive Multi-Rate speech: AMR-NB (.amr) and AMR-WB (.awb) |
How to make subtitles from AMR files
- Hand the file to the bot. Find @potok_now_bot in Telegram and add your .amr file as a message. The bot takes up to 2 GB; very long recordings are better uploaded with the mini app's Upload button.
- Keep the format in mind. A single-channel AMR file holds only a magic number before the speech frames (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.
- A useful detail. Android lists AMR-NB in 3GPP (.3gp) and AMR (.amr) files at 4.75 to 12.2 kbps sampled at 8 kHz.
What the subtitle file looks like
[00:00:01,000 --> 00:00:03,400] Caption 1: Hello, it's Peter from the dentist's office.
[00:00:03,600 --> 00:00:06,100] Caption 2: Your appointment is moved to Thursday morning.
[00:00:06,300 --> 00:00:09,000] Caption 3: Please call back if that time does not work.
[00:00:09,200 --> 00:00:11,800] Caption 4: Hello, I am calling about the parcel that never arrived.
Captions written by us to show the layout. They are not output from a real AMR file.
| Topic | Answer |
|---|---|
| Input | Voice messages, audio and video |
| Short digest | A summary button under the transcript gives a short digest |
| Output formats | TXT, MD, DOCX and PDF for text; SRT and VTT for subtitles |
| Translating | The text keeps the language of the audio and is not translated |
| Spoken languages | About 30 languages with good published results; a few more with warnings |
Typical AMR slips
| Slip | Result | Remedy |
|---|---|---|
| Hoping the AMR file carries its own captions | It only has speech frames, so a player shows none | Keep the SRT as a separate file |
| Sending a quiet AMR call with distant speakers | Low volume speech gives gaps and wrong words in captions | Record closer to the speaker or raise the level |
| Using the SRT times after converting the AMR elsewhere | A trimmed conversion shifts the caption timing | Request the SRT from the exact file you will play |
| Sending an AMR file recorded in a moving car | Engine noise creates wrong words in the captions | Re-record somewhere quiet or review each caption after receiving |
Next steps
Terms used here are explained in the glossary. Handy helpers live in tools; apps are on the download page.
Questions and answers
Can I send AMR files straight to Potok?
Yes. .amr files up to 2 GB go to the bot as they are; there is no conversion step before recognition.
Will the captions be burned into my AMR file?
No. You get a separate .srt or .vtt text file, and your original AMR file stays unchanged.
Which apps and devices create AMR files?
Android MediaRecorder offers an AMR_NB output format (Android MediaRecorder AMR_NB).
Sources
Each source was opened by hand on the date shown. Pages change, so open the source if a detail matters to you.
- RFC 4867: RTP payload format and file storage format for AMR and AMR-WB, IETF · checked
- Supported media formats, Android Developers · checked
Run your own recording through it
Drop an audio or video file, or a voice message, into the chat with @potok_now_bot; the recognized text is sent back there.
Go to @potok_now_bot in Telegram