OPUS to AMR - Convert audio online

Conversion Results:
# Output File Source File Action
How to convert OPUS to AMR:

1. Click the "Choose Files" button to select multiple files from your local device, or click the "URL" button to choose an online file. The source file can also be in video format. Video or audio file size can be up to 200MB. You can use the file analyzer to view the source audio's detailed information, such as track name, genre, bitrate, and sampling rate.

2. Set the target audio format, bitrate, and sample rate. The target audio format can be WAV, WMA, MP3, OGG, AAC, AU, FLAC, M4A, MKA, AIFF, OPUS, or RA.

3. Click the "Convert Now!" button to start batch conversion. It will automatically retry conversion on another server if one fails; please be patient while converting. The output files will be listed in the "Conversion Results" section. Click the icon to show the file QR code or save the file to cloud storage services such as Google Drive, OneDrive, or Dropbox.

OPUS vs AMR:
Name OPUS AMR
Full name Opus Audio Format Adaptive Multi-Rate
File extension .opus .amr, .3ga
MIME audio/opus audio/amr
Developed by IETF codec working group 3GPP
Type of format Audio file format Audio compression format
Introduction Opus is a lossy audio coding format developed by Xiph and standardized by the IETF, designed to efficiently code speech and general audio in a single format, while remaining low-latency enough for real-time interactive communication and low-complexity enough for low end ARM3 processors. 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 Opus supports constant and variable bitrate encoding from 6 kbit/s to 510 kbit/s, frame sizes from 2.5 ms to 60 ms, and five sampling rates from 8 kHz (with 4 kHz bandwidth) to 48 kHz (with 20 kHz bandwidth, the human hearing range). An Opus stream can support up to 255 audio channels, and it allows channel coupling between channels in groups of two using mid-side coding. 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.
Associated programs FFmpeg, AIMP, Amarok, cmus, foobar2000, Mpxplay, MusicBee, SMplayer, VLC media player, Winamp Audacity, FFmpeg, MPlayer, QuickTime, VLC media player
Sample file sample.opus sample.amr
Wikipedia OPUS on Wikipedia AMR on Wikipedia