FFmpeg equivalents

Every ferraus command on this page was run against ferraus 0.1.0.

ferraus does common audio jobs natively, so an agent or person who already knows FFmpeg can translate directly. Anything not listed here still works through the pass-through: ferraus ffmpeg -- <the same ffmpeg arguments> (the exact command line is recorded in the JSON envelope and sidecar). ferraus ffmpeg -- -h prints FFmpeg's own help.

Global flags map the same way everywhere: -ar → --sample-rate, -ac → --channels, -b:a → --bitrate, -sample_fmt s16 → --bit-depth 16, -y → --overwrite, -f wav - (stdout) → -o -.

Conversion and encoding

ffmpeg	ferraus
`ffmpeg -i in.wav out.flac`	`ferraus convert in.wav -o out.flac`
`ffmpeg -i in.flac -c:a libmp3lame -b:a 256k out.mp3`	`ferraus convert in.flac -o out.mp3 --bitrate 256k`
`ffmpeg -i in.flac -c:a libmp3lame -q:a 2 out.mp3`	`ferraus convert in.flac -o out.mp3 --bitrate 190k` (VBR is the default; `--vbr off` for CBR)
`ffmpeg -i in.wav -c:a libopus -b:a 64k out.opus`	`ferraus convert in.wav -o out.opus --bitrate 64k`
`ffmpeg -i in.wav -c:a libvorbis -q:a 5 out.ogg`	`ferraus convert in.wav -o out.ogg --bitrate 160k`
`ffmpeg -i in.wav -c:a aac -b:a 192k out.m4a`	`ferraus convert in.wav -o out.m4a` (uses the FFmpeg bridge for AAC)
`ffmpeg -i in.wav -c:a alac out.m4a`	`ferraus convert in.wav -o out.m4a --format alac` (bridge)
`ffmpeg -i in.wav -sample_fmt s16 out.wav`	`ferraus convert in.wav -o out.wav --bit-depth 16` (TPDF dither; `--dither none` to truncate)
`ffmpeg -i in.wav -c:a pcm_f32le out.wav`	`ferraus convert in.wav -o out.wav --bit-depth 32`
`ffmpeg -i in.wav -ar 44100 out.wav`	`ferraus resample in.wav --to 44100 -o out.wav` or `ferraus convert in.wav -o out.wav --sample-rate 44100`
`ffmpeg -i in.wav -af aresample=resampler=soxr:precision=28 -ar 48000 out.wav`	`ferraus resample in.wav --to 48000 --quality high -o out.wav`
`ffmpeg -i in.wav -f wav - \| other`	`ferraus convert in.wav -o - \| other`
`cat in.wav \| ffmpeg -f wav -i - out.flac`	`cat in.wav \| ferraus convert - --input-format wav -o out.flac`

Inspecting

ffmpeg	ferraus
`ffprobe in.mp3`	`ferraus info in.mp3`
`ffprobe -v error -show_format -show_streams -of json in.mkv`	`ferraus media info in.mkv --json`
`ffprobe -v error -show_entries stream=index,codec_type,codec_name:stream_tags=language in.mkv`	`ferraus media streams in.mkv`
`ffmpeg -i in.wav -af ebur128=peak=true -f null -`	`ferraus analyze loudness in.wav` (or `ferraus info in.wav --loudness`)
`ffmpeg -i in.wav -af volumedetect -f null -`	`ferraus analyze stats in.wav` (peak, true peak, RMS per channel)
`ffmpeg -i in.wav -af astats -f null -`	`ferraus analyze stats in.wav` (add `--histogram` for the level histogram)
`ffmpeg -i in.wav -lavfi showspectrumpic out.png`	`ferraus spectrogram in.wav -o out.png`
`ffmpeg -i in.wav -lavfi showwavespic out.png`	`ferraus waveform in.wav -o out.png`
`ffmpeg -i in.wav -af silencedetect=n=-40dB:d=0.3 -f null -`	`ferraus silence detect in.wav --threshold -40dB --min 300ms`

Editing

ffmpeg	ferraus
`ffmpeg -ss 10 -to 40 -i in.wav out.wav`	`ferraus trim in.wav --range 10s..40s -o out.wav`
`ffmpeg -ss 1:00 -i in.wav out.wav`	`ferraus trim in.wav --range 1:00..end -o out.wav`
`ffmpeg -f concat -safe 0 -i list.txt -c copy out.wav`	`ferraus concat a.wav b.wav c.wav -o out.wav`
`ffmpeg -i a.wav -i b.wav -filter_complex acrossfade=d=2 out.wav`	`ferraus concat a.wav b.wav --crossfade 2s -o out.wav`
`ffmpeg -i in.wav -f segment -segment_time 30 out%03d.wav`	`ferraus split in.wav --every 30s -o 'out{stem}.wav'` (writes `out001.wav`, `out002.wav`, ...; `{stem}` is the part number)
`ffmpeg -i in.wav -af "afade=t=in:d=1,afade=t=out:st=58:d=2" out.wav`	`ferraus fade in.wav --in 1s --out 2s -o out.wav`
`ffmpeg -i in.wav -af volume=-6dB out.wav`	`ferraus gain in.wav --by -6dB -o out.wav`
`ffmpeg -i in.wav -af loudnorm=I=-14:TP=-1 out.wav`	`ferraus normalize in.wav --lufs -14 --ceiling -1dBTP -o out.wav` (`--peak` is a separate peak-normalize mode and cannot be combined with `--lufs`)
`ffmpeg -i in.wav -af dynaudnorm out.wav`	`ferraus leveler in.wav -o out.wav` (slow level riding; `normalize --rms -20dB` for one static gain)
`ffmpeg -i in.wav -af silenceremove=start_periods=1:stop_periods=1 out.wav`	`ferraus silence trim in.wav -o out.wav` (leading and trailing; `--all` also shortens inner pauses)
`ffmpeg -i in.wav -af areverse out.wav`	`ferraus reverse in.wav -o out.wav`
`ffmpeg -i in.wav -af atempo=1.25 out.wav`	`ferraus stretch in.wav --factor 0.8 -o out.wav` (`--factor` multiplies the duration: 1.25x faster is 0.8; or `--to-bpm` with `--bpm`)
`ffmpeg -i in.wav -af asetrate=48000*1.059463,aresample=48000 out.wav`	`ferraus speed in.wav --factor 1.059463 -o out.wav` (varispeed: pitch and tempo together, like the ffmpeg line) or `ferraus pitch in.wav --semitones 1 -o out.wav` (pitch only, duration kept)

Channels

ffmpeg	ferraus
`ffmpeg -i in.wav -ac 1 out.wav`	`ferraus channels in.wav --to mono -o out.wav` (or `--channels 1` on any command)
`ffmpeg -i in.wav -ac 2 out.wav`	`ferraus channels in.wav --to stereo -o out.wav`
`ffmpeg -i in.wav -af "pan=mono\|c0=FL" left.wav`	`ferraus channels in.wav --extract L -o left.wav`
`ffmpeg -i in.wav -af channelmap=1\|0 out.wav`	`ferraus channels in.wav --swap -o out.wav`
`ffmpeg -i in.wav -filter_complex channelsplit out_L.wav out_R.wav`	`ferraus channels in.wav --extract L -o L.wav` and `--extract R -o R.wav`
`ffmpeg -i a.wav -i b.wav -filter_complex amix=inputs=2 out.wav`	`ferraus mix a.wav b.wav -o out.wav`

Filters

ffmpeg	ferraus
`ffmpeg -i in.wav -af highpass=f=80 out.wav`	`ferraus highpass in.wav --freq 80Hz -o out.wav` (or `ferraus eq in.wav --band highpass:80Hz -o out.wav`)
`ffmpeg -i in.wav -af "equalizer=f=1000:t=q:w=1:g=3" out.wav`	`ferraus eq in.wav --band peak:1kHz:+3dB -o out.wav`
`ffmpeg -i in.wav -af acompressor=threshold=-18dB:ratio=4 out.wav`	`ferraus compress in.wav --threshold -18dB --ratio 4:1 -o out.wav`
`ffmpeg -i in.wav -af alimiter=limit=0.89 out.wav`	`ferraus limit in.wav --ceiling -1dBTP -o out.wav`
`ffmpeg -i in.wav -af afftdn out.wav`	`ferraus denoise in.wav -o out.wav`
`ffmpeg -i in.wav -af "aecho=0.8:0.9:60:0.4" out.wav`	`ferraus echo in.wav --taps 1 --time 60ms --feedback 40% -o out.wav`
`ffmpeg -i in.wav -af "highpass=f=80,loudnorm=I=-16" out.wav`	`ferraus fx in.wav --fx "eq:band=highpass:80Hz" --fx "normalize:lufs=-16" -o out.wav`

Video containers

ffmpeg	ferraus
`ffmpeg -i video.mp4 -vn audio.wav`	`ferraus media extract-audio video.mp4 -o audio.wav` (decoded natively)
`ffmpeg -i video.mp4 -vn -c:a copy audio.m4a`	`ferraus media extract-audio video.mp4 --copy`
`ffmpeg -i movie.mkv -map 0:a:1 commentary.flac`	`ferraus media extract-audio movie.mkv --track 1 -o commentary.flac`
`ffmpeg -i video.mp4 -i new.wav -map 0:v -map 1:a -c:v copy -c:a aac out.mp4`	`ferraus media replace-audio video.mp4 new.wav -o out.mp4`
`ffmpeg -i video.mp4 -i new.wav -map 0:v -map 1:a -map 0:a -c:v copy out.mkv`	`ferraus media replace-audio video.mp4 new.wav --keep-original -o out.mkv`
`ffmpeg -i in.mkv -map 0 -c copy out.mp4`	`ferraus media remux in.mkv -o out.mp4`
`ffmpeg -i video.mp4 -af loudnorm=I=-16 -c:v copy out.mp4`	`ferraus media extract-audio video.mp4 -o a.wav && ferraus normalize a.wav --lufs -16 -o b.wav && ferraus media replace-audio video.mp4 b.wav -o out.mp4`
anything else (scaling, subtitles, thumbnails, overlays)	`ferraus ffmpeg -- <ffmpeg arguments>` (a native `ferraus video` namespace is reserved for v2)

Getting FFmpeg

The bridge looks for FERRAUS_FFMPEG (or ffmpeg.path in the config), then the managed build in the ferraus cache, then ffmpeg on PATH. ferraus doctor --install-ffmpeg downloads a pinned, SHA-256-verified static build (LGPL builds on Linux and Windows; the macOS build is GPL) and shows its license; ferraus doctor reports which binary is in use.