Playback

Built-in audio player with waveform display, loop mode, markers, and Audio Unit support.

Basic Playback

Select a file in the list and press Space to play. Press Space again to pause. The waveform view shows playback position in real time. Double-clicking a row also starts playback, as long as the cell you double-clicked isn't an editable one.

Shortcut	Action
Space	Play / pause
Return / Home	Return to start
← / →	Rewind / advance by beat
⇧← / ⇧→	Rewind / advance by bar

Waveform View

The waveform view shows a visual representation of the audio. Waveforms are drawn on first load and saved so they appear instantly the next time.

Zooming

• Use ⌘+ and ⌘- to zoom in and out.
• Use ⇧Z to fit the entire file in view.

Scrubbing

Click anywhere in the waveform to move the playhead to that position. Click and drag to scrub.

Ruler

The ruler above the waveform displays time position. Choose the readout with View > Time Display — Real Time for seconds and minutes, or Timecode for SMPTE. Your choice is remembered between sessions.

When a file carries a start timecode, ShadowTag reads it and offsets the ruler and transport to match, so positions line up with the timecode of the original source rather than starting from zero.

Enable Show Bar Numbers to overlay bar and beat markers on the ruler based on the file's BPM tag. This requires a BPM value to be present in the file's metadata or set manually in the transport.

Multichannel Files

For multichannel files with iXML track names, per-channel labels appear in a static header column next to the waveform. Click a label to edit it in a popover.

Multiple Audio Tracks

Files carrying more than one audio track — Matroska containers and many video files — enable the Editor > Audio Track menu, which lists the tracks found in the current file by name and language. Choosing a track switches playback to it and redraws the waveform for that track. The choice is remembered per file, and format conversion uses the same selected track.

Video Files

Video files show a thumbnail timeline alongside the waveform, sampled across the video's duration, and the file preview displays the full video frame rather than cropping it to fill. Read-only technical details for the video (resolution, frame rate, codec, capture date, GPS location, and more) appear in the File tab of the Metadata panel — see Metadata.

Matroska and WebM video (.mkv, .webm) plays alongside the formats macOS handles natively. When a container cannot be played directly, ShadowTag shows a still frame taken from the middle of the clip together with the file's waveform. Files with Apple's DRM are marked (Protected) and cannot be played.

MXF files play when Apple's Pro Video Formats package is installed. It is a free download from Apple. Without it, MXF files are skipped on import with a note saying what to install. MXF is read-only: tags and trims are not written back.

Detached Preview

View > Preview in New Window (⌘⇧D) moves the media preview into its own floating window, which can be sized and positioned independently of the main window. View > Preview Full Screen (⌘⇧F) takes the preview full screen; press Esc to leave. Both are toggles, and the detached state is saved with your workspace and restored on the next launch. In the main window the preview sits above the File properties on a divider you can drag. Its height is saved with the workspace.

Loop Mode

Toggle loop mode with ⌘L or the loop button in the transport. When active, playback repeats continuously from the current start position (or loop region if one is set).

To set a loop region: drag across the waveform to create a selection. The shaded region defines the loop in and out points. Clear the region by clicking outside it.

Snap to Grid

Editor > Snap snaps selection in and out points to bar, beat, eighth-note, or sixteenth-note divisions based on the file's BPM. The chosen snap value is saved with the workspace.

Playlist Mode

When playlist mode is active, playback automatically advances to the next file in the list when the current file ends. Toggle with the playlist mode button in the transport.

Markers

Markers are cue points or regions embedded in the audio file. They appear as vertical lines in the waveform view.

Creating Markers

• Press M during playback to drop a marker at the current playhead position.
• Use Editor > Create Marker from the menu.
• Press ⌥M (or Editor > Create Segment Marker) to create a segment region from the current selection — or a one-second region at the playhead if nothing is selected. Overlapping regions are resolved automatically: fully-enclosed ones are removed and partially-overlapping ones are trimmed, with the segments renumbered by position. The whole step is a single undo.

Navigating Markers

Click a marker line in the waveform to move the playhead to that position. Press Tab to step to the next marker and ⇧Tab to the previous one. Markers are also listed in the Markers tab of the Metadata panel, where you can rename or delete them.

Region Markers

Region markers span a range rather than a single point. Dragging a region updates the editor's selection to match. Shift-click a region to extend the selection to include it, or Shift-double-click to set the selection to the region's full range.

Audio Units

ShadowTag can load Audio Unit (AU) plug-ins as effects on the playback signal chain. This lets you audition files with EQ, compression, reverb or any other effect, in real time, without changing the file.

To add an Audio Unit:

1. Click the button next to the level meter in the transport area to open the Audio Unit panel.
2. Click the + button to browse available plug-ins.
3. Select a plug-in to add it to the chain.
4. Click the plug-in name to open its UI.

Audio Units can be switched off entirely with the Audio Units toggle in Settings. Off takes every plug-in out of the signal path, hides the Audio Units button and stops checking the system's plug-ins; the chain is kept and returns when Audio Units are switched back on.

A Remove All Effects action in the Audio Unit panel clears the entire chain at once.

The AU chain is part of your workspace and is restored on next launch.

AU presets are stored in ~/Library/Audio/Presets/, the macOS-standard preset folder shared across AU hosts — so presets you save in ShadowTag are available in other applications and vice versa.

Settings includes a Validate Audio Units button that runs a validation pass across the installed AU plug-ins. The resulting report dialog lists any plug-ins that failed, with a Copy Report action for sharing the output.

Audio Editing

ShadowTag includes non-destructive audio editing — fade, trim, and normalize — that applies to playback in real time and only modifies the source file when you explicitly save. The dirty column in the file list reflects each file's current state — clean, pending metadata edit, pending audio edit, locked, unplayable, missing, or in the Trash — with a distinct indicator for each. Sorting by the dirty column groups files by these states.

Fade Handles

Drag the fade-in or fade-out handles at the start and end of the waveform to set fade regions. Fade-in and fade-out have independent taper shapes — drag the taper handle at the midpoint of each fade region up or down to sweep between reverse-audio, linear, and default audio curves. Fades can also be applied to a selection via Tools > Fade Selection (⌥F) or with detailed control via Tools > Fade with Options (⌘⌥F); clear with Clear Fades (⌥⇧F).

Trim Handles

Trim handles in the audio editor define playback in and out points. Press I with the playhead at the desired position to set the in point; press O to set the out point. Playback is bounded by the trim range; the original audio outside the range is preserved until you save. Tools > Crop Selection (⌘I) bounds playback to the current selection. Clear with Clear Trim (⌥⇧I).

Trimming applies to video files as well as audio. Saving a trimmed video renders the result with every track intact. Fades and normalize are not available for video — their handles are disabled, and ShadowTag says why.

Transport Options Menu

An options button (…) on the transport bar holds the audio editing commands — Normalize, Fades, Trim and Segments, with their Clear actions — plus Detect Tempo, Detect Loudness, Time Display, Show Bar Numbers, Snap and Audio Track.

Beside it, the Spot button sends the selection straight to the timeline of the application chosen in Spot Settings. Click its arrow, or right-click it, for the Spot commands and Spot Settings — see Spot to Timeline.

Output Device

ShadowTag plays audio through the system's default output device. To change it, open Settings > Audio and click Open Audio MIDI Setup to launch macOS's Audio MIDI Setup utility, where output devices and routing can be configured.

Metronome

Toggle the built-in metronome with ⌘⌥M or the metronome button in the transport. The metronome uses the BPM from the currently playing file's metadata, or a manually set tempo if no BPM tag is present.

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