Convert AVI to AMR — Free Online Tool
Convert AVI video files to AMR audio, extracting and re-encoding the audio track using the libopencore_amrnb codec optimized for speech. AMR's narrow-band compression makes it ideal when you need to pull voice content from legacy AVI recordings for mobile telephony or voice messaging systems.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your AVI file here
or click to browse
Free — no uploads, no signups. Your files never leave your browser.
Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
Because AMR is a pure audio format with no video container support, FFmpeg discards the AVI video stream entirely and focuses solely on transcoding the audio track. The audio — whether it was stored as MP3, AAC, or Vorbis inside the AVI — is decoded and then re-encoded using the libopencore_amrnb (Adaptive Multi-Rate Narrow-Band) codec at 12,200 bps by default. AMR-NB was specifically designed for speech frequencies (300 Hz–3400 Hz), so the codec aggressively filters out non-speech content, resulting in very small file sizes. If your AVI has multiple audio tracks, only the first track is extracted. This is a lossy transcode: the original audio fidelity cannot be recovered from the resulting AMR file.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg transcoding engine. In this browser-based tool, FFmpeg runs via WebAssembly (FFmpeg.wasm) locally in your browser — no data is sent to a server. |
-i input.avi
|
Specifies the AVI source file. FFmpeg reads the AVI container, which may contain a video stream and one or more audio streams encoded as MP3, AAC, or Vorbis — all of which are decoded before the AMR encode step. |
-c:a libopencore_amrnb
|
Selects the libopencore_amrnb encoder to produce AMR Narrow-Band audio, the standard codec for mobile telephony and voice messaging. This encoder hard-limits output to mono at one of eight fixed bitrates defined by the 3GPP AMR-NB specification. |
-b:a 12200
|
Sets the AMR-NB bitrate to 12,200 bps (Mode 7 / MR122), the highest quality mode available in the AMR-NB standard. This value must be one of the eight fixed AMR-NB rates — arbitrary values will be rounded or rejected by the encoder. |
output.amr
|
Defines the output filename and format. The .amr extension tells FFmpeg to write an IETF AMR file containing only the re-encoded narrow-band audio stream; the video track from the source AVI is automatically discarded since AMR has no video support. |
Common Use Cases
- Extracting spoken dialogue or narration from old AVI training videos to create voice clips compatible with mobile telephony systems or IVR platforms
- Pulling interview audio from legacy AVI camcorder footage for submission to voice transcription services that accept AMR format from mobile devices
- Converting AVI-recorded voicemail announcements or auto-attendant scripts into AMR for direct upload to GSM or VoIP phone systems
- Archiving the spoken commentary track from AVI sports or event recordings in a compact AMR file for storage-constrained environments
- Extracting speech from AVI surveillance or bodycam footage into AMR format for use in legal evidence management systems that require mobile-compatible audio
Frequently Asked Questions
Yes, noticeably so if the original AVI contained music or broadband audio. AMR Narrow-Band (AMR-NB) is engineered specifically for human speech in the 300–3400 Hz range — the same bandwidth used in traditional phone calls. Music, background sounds, and high-frequency detail are heavily attenuated or lost. For spoken-word content like interviews or narration, intelligibility is generally good, but the audio will sound 'telephone-like' compared to the original.
AMR-NB was standardized by 3GPP for GSM mobile networks, where bandwidth was extremely constrained. The codec operates at eight fixed mode bitrates ranging from 4,750 bps to 12,200 bps — these are the only valid values; arbitrary bitrates are not supported. The default of 12,200 bps (Mode 7, also called MR122) delivers the best quality within the AMR-NB standard and is the most universally compatible with phone systems and AMR players.
No. AMR is a pure audio container and cannot store video data. FFmpeg automatically drops the video stream from the AVI when writing to an AMR output file. You will not lose the video permanently — your original AVI remains untouched — but the output .amr file will contain only the re-encoded audio.
Replace the value after -b:a with any of the AMR-NB standard rates: 4750, 5150, 5900, 6700, 7400, 7950, 10200, or 12200. For example, use -b:a 7950 for a balance of size and speech quality, or -b:a 4750 for the smallest possible file. Be aware that values below 7950 may reduce speech intelligibility, especially in noisy AVI recordings.
Yes. Replace -c:a libopencore_amrnb with -c:a libopencore_amrwb in the command and adjust -b:a to a wideband-compatible rate. AMR Wideband covers 50–7000 Hz and delivers noticeably cleaner speech, though it is a separate standard (3GPP TS 26.201) and some older mobile systems only accept AMR-NB files. Check your target platform's compatibility before choosing wideband.
FFmpeg selects the first audio stream by default. Since AMR supports only a single mono audio track, all other audio streams in the AVI are discarded. If the dialogue or content you need is on a secondary track, you can specify it explicitly by adding -map 0:a:1 (for the second audio track) before the output filename in the FFmpeg command.
Technical Notes
AMR-NB enforces mono audio output — if the AVI's audio track is stereo or surround, FFmpeg automatically down-mixes it to mono during the transcode. This is a hard limitation of the AMR-NB codec specification, not a tool restriction. The resulting .amr file uses the IETF storage format with a '#!AMR
' magic header, which is distinct from the raw bitstream used in some 3GPP containers. Metadata from the AVI (title, author, creation date) is not preserved in AMR, as the format has no standardized metadata block. Because AVI can store audio as MP3 (libmp3lame) or AAC internally, the conversion always involves full decode-and-re-encode — there is no possibility of a stream copy shortcut here. File sizes will typically be dramatically smaller than the source AVI: a one-minute AVI at typical quality might shrink to roughly 90 KB at 12,200 bps AMR, making this format impractical for anything other than speech-centric content.
' magic header, which is distinct from the raw bitstream used in some 3GPP containers. Metadata from the AVI (title, author, creation date) is not preserved in AMR, as the format has no standardized metadata block. Because AVI can store audio as MP3 (libmp3lame) or AAC internally, the conversion always involves full decode-and-re-encode — there is no possibility of a stream copy shortcut here. File sizes will typically be dramatically smaller than the source AVI: a one-minute AVI at typical quality might shrink to roughly 90 KB at 12,200 bps AMR, making this format impractical for anything other than speech-centric content.