Concatenate Audio
AI-generatedSummary
Concatenates audio from all incoming items in order, or joins named binary properties from each item, into an output audio file. FFmpeg resamples inputs to a common sample rate and channel layout; optional settings control format, bitrate, gaps or crossfades, loudness normalization, and output naming.
Inputs
- Binary Property — Binary property holding each input audio file in All Input Items mode; defaults to
data. Items without this property are skipped, and the operation errors if none contain it. - Input Mode — Choose All Input Items to combine matching binary properties across incoming items into one output, or Multiple Binary Properties to combine named properties separately for each item. Defaults to All Input Items.
- Binary Properties — In Multiple Binary Properties mode, provide comma-separated binary property names in join order; defaults to
data,data1. Each named property must exist on the item. - Output Format — Select MP3, WAV, OGG, FLAC, AAC, or M4A, or keep the first input's format. Defaults to keeping the first input's format.
- Bitrate — Optional output bitrate: 64, 128, 192, 256, or 320 kbps; Auto leaves it unspecified.
- Sample Rate — Resample all inputs to 22050, 44100, or 48000 Hz, or match the first input. Auto falls back to 44100 Hz if probing fails.
- Channels — Convert all inputs to mono, stereo, or match the first input. Auto falls back to stereo if probing fails; channel counts wider than mono are converted to stereo.
- Gap Duration (seconds) — Insert this duration of silence between files when greater than zero and crossfade is off; defaults to 0.
- Crossfade Duration (seconds) — Overlap each adjacent pair with a crossfade of this duration when greater than zero. This takes precedence over gaps; each file must be longer than the crossfade duration.
- Normalize — Optionally apply Podcast (-16 LUFS), YouTube (-14 LUFS), Broadcast (-23 LUFS), or a custom loudnorm filter to the joined audio.
- Normalize Custom Value — Custom loudnorm filter used when Normalize is set to Custom.
- Output File Name — Set the output filename. When empty, the operation derives it from the first input filename, or uses
concatenatedif that filename is unavailable, and applies the output extension. - Output Binary Property — Name the binary property containing the resulting audio; defaults to
data.
Output shape
One output item in All Input Items mode; one output item per incoming item in Multiple Binary Properties mode. Each has the joined audio in the configured binary property and JSON metadata.
JSON metadata includes operation, input count, gap and crossfade durations, sample rate, channels, duration, output format, and output size. Multiple Binary Properties mode also includes the property names used. The operation requires FFmpeg and ffprobe to process and inspect audio.