avconv

avconv is a command-line multimedia processing tool developed by the Libav project. It provides facilities to convert, encode, decode, transcode, mux, demux, stream, filter, and play audio and video content. In many contexts it is presented as a drop-in replacement for FFmpeg's ffmpeg, sharing a common set of features and programming interfaces.

History: Libav originated in 2011 as a fork of FFmpeg. Avconv is the primary command-line interface for Libav's tools. The project aimed to deliver a stable API, cleaner code, and forward-looking design. As FFmpeg continued to evolve more rapidly and widespread adoption favored FFmpeg, avconv's prominence declined and many distributions and users migrated back to FFmpeg.

Capabilities: Avconv relies on Libav libraries such as libavcodec, libavformat, libavfilter, libavutil, libswscale, and libswresample. It supports decoding and encoding for a wide range of formats, format conversion, bitrate and codec changes, trimming, remuxing, streaming, and applying video and audio filters. It can also capture from devices and perform basic processing pipelines.

Usage: The command-line options resemble those of FFmpeg, with input specified by -i and output files defined at the end of the command, along with per-stream options (-c:v, -c:a, -b:v, -b:a) and filters (-vf, -af). Example: avconv -i input.avi -c:v libx264 -crf 23 -preset fast output.mp4. While capable, avconv's development has slowed relative to FFmpeg, and many users now prefer FFmpeg for new projects.