| Format introduction | The Adaptive Multi-Rate (AMR or AMR-NB or GSM-AMR) audio codec is an audio compression format optimized for speech coding. AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS. |
| Technical details | AMR speech codec consists of a multi-rate narrowband speech codec that encodes narrowband (200-3400 Hz) signals at variable bit rates ranging from 4.75 to 12.2 kbit/s with toll quality speech starting at 7.4 kbit/s. Sampling frequency 8 kHz/13-bit (160 samples for 20 ms frames), filtered to 200-3400 Hz. |
| File extension | .amr, .3ga |
| MIME | audio/amr |
| Developed by | 3GPP |
| Type of format | Audio compression format |
| Associated programs | Audacity, FFmpeg, MPlayer, QuickTime, VLC media player |
| Wiki | https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_codec |
| AMR to MP3 | convert from audio to audio |
| AMR to WAV | convert from audio to audio |
| AMR to OGG | convert from audio to audio |
| AMR to WMA | convert from audio to audio |
| AMR to AAC | convert from audio to audio |
| AMR to AU | convert from audio to audio |
| AMR to FLAC | convert from audio to audio |
| AMR to M4A | convert from audio to audio |
| AMR to MKA | convert from audio to audio |
| AMR to AIFF | convert from audio to audio |
| AMR to OPUS | convert from audio to audio |
| AMR to RA | convert from audio to audio |
| AVI to AMR | convert from video to audio |
| 3GP to AMR | convert from video to audio |
| M2V to AMR | convert from video to audio |
| MPEG to AMR | convert from video to audio |
| WMV to AMR | convert from video to audio |
| MP4 to AMR | convert from video to audio |
| MKV to AMR | convert from video to audio |
| M2TS to AMR | convert from video to audio |
| WEBM to AMR | convert from video to audio |
| FLV to AMR | convert from video to audio |
| SWF to AMR | convert from video to audio |
| ASF to AMR | convert from video to audio |
| MOV to AMR | convert from video to audio |
| M4V to AMR | convert from video to audio |
| RM to AMR | convert from video to audio |
| VOB to AMR | convert from video to audio |
| OGV to AMR | convert from video to audio |
| MP3 to AMR | convert from audio to audio |
| WAV to AMR | convert from audio to audio |
| OGG to AMR | convert from audio to audio |
| WMA to AMR | convert from audio to audio |
| AAC to AMR | convert from audio to audio |
| AU to AMR | convert from audio to audio |
| FLAC to AMR | convert from audio to audio |
| M4A to AMR | convert from audio to audio |
| MKA to AMR | convert from audio to audio |
| AIFF to AMR | convert from audio to audio |
| OPUS to AMR | convert from audio to audio |
| RA to AMR | convert from audio to audio |