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| Name | AMR | MP3 |
| Full name | AMR - Adaptive Multi-Rate | MP3 - MPEG-1 or MPEG-2 Audio Layer III |
| File extension | .amr, .3ga | .mp3 |
| MIME type | audio/amr | audio/mpeg, audio/MPA, audio/mpa-robust |
| Developed by | 3GPP | Fraunhofer Institute |
| Type of format | Audio compression format | Digital audio |
| Description | 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. | MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is an audio coding format for digital audio which uses a form of lossy data compression. It is a common audio format for consumer audio streaming or storage, as well as a de facto standard of digital audio compression for the transfer and playback of music on most digital audio players. |
| 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. | The use of lossy compression is designed to greatly reduce the amount of data required to represent the audio recording and still sound like a faithful reproduction of the original uncompressed audio. An MP3 file that is created using the setting of 128 kbit/s will result in a file that is about 1/11 the size of the CD file created from the original audio source. |
| Associated programs | Audacity, FFmpeg, MPlayer, QuickTime, VLC media player | VLC media player, MPlayer, Winamp, foobar2000. |
| Wiki | https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_codec | https://en.wikipedia.org/wiki/MP3 |