jq for binary formats - tool, language and decoders for working with binary and text formats.

fq is inspired by the well known jq tool and language and allows you to work with binary formats the same way you would using jq. In addition it can present data like a hex viewer, transform, slice and concatenate binary data. It also supports nested formats and has an interactive REPL with auto-completion.

It was originally designed to query, inspect and debug media codecs and containers like mp4, flac, mp3, jpeg. But has since then been extended to support a variety of formats like executables, packet captures (with TCP reassembly) and serialization formats like JSON, YAML, XML, ASN1 BER, Avro, CBOR, protobuf. In addition it also has functions to work with URL:s, convert to/from hex, number bases, search for things etc.

Basic Pitch, a free audio-to-MIDI converter with pitch bend detection, built by Spotify.
Basic Pitch is a Python library for Automatic Music Transcription (AMT), using lightweight neural network developed by Spotify's Audio Intelligence Lab.

Basic Pitch @ GitHub

Your online audio toolkit.
A collection of easy-to-use web tools for all your audio files.

Opus is a totally open, royalty-free, highly versatile audio codec. Opus is unmatched for interactive speech and music transmission over the Internet, but is also intended for storage and streaming applications. It is standardized by the Internet Engineering Task Force (IETF) as RFC 6716 which incorporated technology from Skype's SILK codec and Xiph.Org's CELT codec.

MP3FS is a read-only FUSE filesystem which transcodes audio formats (currently FLAC) to MP3 on the fly when opened and read. This was written to enable me to use my FLAC collection with software and/or hardware which only understands the MP3 format e.g. gmediaserver to a Netgear MP101 MP3 player.