mpress

Overview

A command-line tool that shrinks photos, videos, and audio files with minimal configuration. Point it at a file or directory and it picks the best available compression strategy automatically — lossless by default, quality re-encode when you want real size reduction.

Features

• Lossless image optimization — JPEG via jpegtran, PNG via oxipng/optipng, with Pillow as a universal fallback for WebP, TIFF, GIF, and anything else
• Video remux & re-encode — lossless container remux by default; opt into H.265 re-encoding (with H.264 fallback) at a configurable CRF for 40–60% size reduction
• Audio compression — FLAC re-compressed at maximum level 12; optional Opus encoding at a configurable bitrate for 50–80% reduction vs. lossless originals
• Smart codec pre-checks — automatically skips files already in efficient formats (H.265, VP9, AV1, Opus) to avoid wasted encoding
• Parallel processing — images and audio run across available CPU cores (auto-adjusted for current system load); videos are serialized since ffmpeg already saturates cores internally
• Rich live progress — per-file and overall progress bars with time remaining when running in a TTY; clean plain-text output for pipes and logs
• Flexible output modes — write alongside the original (.min suffix by default), replace in-place, or dry-run to preview savings
• Safe temp-file writes — always encodes to a system temp directory first, then atomically moves to the destination; temp dirs are cleaned up on exit, crash, or SIGTERM

Stack

• Python 3.12
• uv
• Pillow
• ffmpeg
• jpegtran
• oxipng
• Rich
• Hatchling

Links

• GitHub