Presave Audio

Audio in ComfyUI is a second-class citizen compared to images - most workflows generate it, lose it, and never listen to it until the final export. MKRPresaveAudio is the audio half of the Presave family: same preview-first philosophy as MKRPreSave and MKRPresaveVideo, applied to sound. preview_only defaults to true, so it plays/looks at what you've got without writing files; flip it off when the take is good.

What it's for

You'll use it after an audio-generation or processing node when you want a quick check before committing bytes to disk. The audio input is the * wildcard again - it accepts a file path, a raw waveform tensor, or an MKR_AUDIO payload from another MKRShift node. If it can recognize a file source it previews straight from that; if it gets a waveform it encodes it on the fly. Then, when preview_only is off, it writes to output/<subfolder> in your format of choice.

It's an output node that always reruns, and it has a custom frontend from the pack's WEB_DIRECTORY - the author's own UI for it.

Inputs that matter

• audio - file, waveform, or MKR_AUDIO payload.
• preview_only - True = just preview, False = write the file.
• output_format - auto, wav, mp3, flac, ogg. auto keeps the source format when detectable.
• filename_prefix (default MKR_audio), subfolder, overwrite, and optional filename_label - the usual output plumbing.

Installing it

Same pack install:

cd ComfyUI/custom_nodes
git clone https://github.com/criskb/MKRShift_Nodes

restart ComfyUI (or Manager → MKRShift_Nodes). The dependency note that keeps coming back: the README calls for ffmpeg on your PATH for the audio/video export nodes. WAV is fine to write without it, but mp3, flac, and ogg encoding goes through ffmpeg - skip it and those formats won't encode properly.

Common issues

The recurring one is trying to write mp3 without ffmpeg installed and getting a warning (or an auto fallback) instead of a file. Check ffmpeg -version before assuming the pack is broken. The other subtlety: waveform inputs carry no filename or format info, so an auto output format has nothing to detect and picks a default - if you want a specific container, say so instead of hoping auto guesses. And because it's a preview-first node, the same "I forgot to uncheck preview_only" trap that bites MKRPreSave applies here too.