The .amr filename extension refers to the adaptive multi-rate audio codec initially released in 1999. The format is typically used to encode speech audio and is optimized for this purpose. It can encode speech into one of two file version, either AMR-NB (narrow Band) or AMR-WB (Wide Band) which supports a broader frequency. Because of its optimization for speech audio, the format has been widely adopted as the standard speech codec for GSM and UMTS mobile phone networks by the 3rd Generation Partnership Project ' a collaborative group of organizations in the telecommunications industry.
First released in 1995 and developed by the Fraunhofer Society, the mp3 audio format is arguably one of the most recognizable audio file format that ever existed. This digital audio encoding format hails from the lossy data compression algorithm family. The format enjoys widespread support and compatibility with most handheld music players, smartphones, computers, and in car stereos most of which have native support for the format. It is also a popular format used for distribution of audio files over computer networks such as the internet. Free mp3 encoders such as LAME and audacity give authors the tools necessary to create .mp3 files.
FreeFileConvert uses tuned encoding for AMR to MP3 conversions, preserving clarity while trimming file size. Finished audio streams instantly across phones, tablets, desktops, and modern browsers without extra tweaks.
Upload AMR files from desktop, tablet, or cloud storage, queue multiple jobs, and let the converter finish autonomously. Return whenever convenient to download synchronized MP3 results on any device you rely on.
Process up to 5 files sized 1000 MB per batch without splitting queues manually. Mixed-format uploads convert together, producing consistent MP3 audio with dependable progress tracking.
AMR format encodes narrow band signals between 200 and 3400 hertz at a maximum bitrate of 12.2 kilobits per second. The format employs the ACELP ' Algebraic code-excited linear prediction algorithm, a proprietary speech encoding method created by the VoiceAge Corporation.
The MP3 format compression algorithm works through perceptual coding. A technique in which audio artifacts outside the auditory range of the average human, are reduced or 'cancelled out'. The result is a near perfect replication of the original audio sample at a compression ratio of 11 to 1 at 128 kilobits per second. Audio quality can be controlled by such factors as the bit rate, sample rate, among other features. But bits rates being the main determinant of audio quality can be adjusted between the typical range from 128 kb/s to as high as 320kb/s.
Upload your audio file in the AMR format from your device, Dropbox, or Google Drive.
Select MP3 as the output format and click Convert. Adjust optional settings if needed.
Download the converted audio file. Each file stays available for up to 5 downloads.