Settings for presentation of spectrograms in the audio track. Settings to control the behaviors of Tracks. Interface behaviors, dB display range, choose language and location of Manual, show initial 'Help' dialog. Settings for MIDI playback on your system.Ĭhoose sample rate, sample format and options for rate and format conversion. Settings for playthrough, latency, Sound Activated Recording and naming newly recorded tracks. Length of previews for cuts and effects playback seek times.

The description page for each section (accessed by the links below) shows an image of the default preferences settings for that section.Ĭhoose audio host, playback and recording devices and recording channels.

Sampling frequency 8 kHz/13-bit (160 samples for 20 ms frames), filtered to 200-3400 Hz.The Preferences dialog is split into sections and sub-sections. 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.ĪMR 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. 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). AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS. The Adaptive Multi-Rate (AMR or AMR-NB or GSM-AMR) audio codec is an audio compression format optimized for speech coding.

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.

Opus codec audacity ffmpeg