Video Soundtrack Replacer and Mixer

Video Soundtrack Replacer and Mixer is a desktop audio-to-video muxing, soundtrack
replacement, and multi-track audio mixing tool for Linux powered by bundled FFmpeg.
A lightweight Linux alternative to desktop video soundtrack editor utilities, it
replaces, mixes, tags, or strips audio tracks on MP4, MKV, and MOV videos using
instant lossless video stream copy (-c:v copy) without re-encoding video frames.

Key Features:
- Instant Lossless Video Copy (-c:v copy): Replace or strip video audio tracks in
seconds while preserving 100% original video stream quality.
- Soundtrack Mixing & Sync Offset: Blend original video audio with external MP3, WAV,
FLAC, AAC, OGG, or Opus soundtracks using amix volume balance, millisecond (+/-ms)
audio sync offset, background track looping, and smooth end fade-out.
- Multi-Track Language Tagging: Mux multiple external audio tracks into MKV, MP4, or
MOV containers with ISO-639-2 language codes and custom track titles.
- Real PCM Waveform & Stream Verification: Visualizes real decoded audio waveforms,
peak/RMS dBFS levels, and probes output containers to verify every muxed track.

Disclaimer: This project is an independent open-source tool and is not affiliated with, sponsored by, or endorsed by Leawo Software.