Media and layer matrix

The editor separates three concepts that can look interchangeable at first:

A source asset is uploaded, selected from the workspace library, or returned by a supported service.
A timeline layer is one use of that source in the current draft.
An evaluated frame is what the preview and final H.264 render produce at a specific composition frame.

Changing one timeline layer does not rewrite its source asset. Duplicating a layer creates another timeline instance that may continue to reference the same media.

Acquisition and authoring

Kind	Bin / Library	Upload or drop	Clipboard	Draw / insert tool	AI Search
Video	✓	✓	Copied Tessact layer	—	Supported video result
Livestream source	Library only; final MP4 or ready chunk group	—	—	—	—
Audio	✓	✓	Copied Tessact layer	—	Supported audio result
Image	✓	✓	PNG or copied Tessact layer	—	Supported image result
GIF	✓	✓	Copied Tessact layer	—	—
Text	Draft-local	Plain text creates a layer when pasted on canvas	✓	`T`	—
Solid	Draft-local	—	Copied Tessact layer	`R`	—
Frame	Draft-local	—	Copied Tessact layer	`F`	—
Captions	Draft-local, derived from a video layer with detected audio/subtitle metadata	—	Copied Tessact layer	Caption creation action	—

Preview and timeline behavior

Layer	Visible on canvas	Timeline visualization	Has source-time mapping	Can carry audio	Frame-trimmable	Split at interior playhead
Video	✓	Filmstrip when decode succeeds	✓	✓, if the source contains audio	✓	✓
Livestream group	✓	Grouped video clip and update placeholder when source grows	Chunk-aware mapping	✓, when recorded chunks contain audio	✓	✓, subject to group detachment semantics
Audio	—	Waveform when decode succeeds	✓	✓	✓	✓
Image	✓	Thumbnail / color-identifiable clip body	—	—	✓	✓
GIF	✓	Animated-media clip body; no filmstrip	Playback rate; verify continuity after structural edits	—	✓, with continuity caveat	✓, with restart caveat
Text	✓	Named text layer	—	—	✓	✓
Solid	✓	Color-identifiable layer	—	—	✓	✓
Frame	Container plus appearance	Frame layer with nested descendants	—	—	✓	✓, subject to structural eligibility
Captions	✓ when tokens are active	Caption layer	Token timestamps map from milliseconds	—	✓	✓

All timeline layers have a composition start and frame duration. “Source-time mapping” means the layer additionally maps those composition frames into a decoded source using a source offset and, where supported, playback rate.

Inspector capability summary

Layer	Transform	Crop	Playback rate	Inspector volume	Typography	Layout	Effects	Shadows
Video	✓	✓	✓	If source has audio	—	—	✓	✓
Audio	—	—	✓	✓	—	—	—	—
Image	✓	✓	—	—	—	—	✓	✓
GIF	✓	✓	✓	—	—	—	✓	✓
Text	✓	✓	—	—	✓	—	Typewriter / blur	✓
Solid	✓	✓	—	—	—	—	—	✓
Frame	✓	✓	—	—	—	✓	✓	✓
Captions	✓	✓	—	—	✓	—	Typewriter / blur	✓

For individual fields, read the Property matrix.

Source mapping

For an active media layer:

source time = source in-point
            + time elapsed since the layer begins × playback rate

The preview evaluates a layer from its start through its last active composition frame. A left trim normally advances the video or audio source in-point; a right trim shortens the active duration. Playback rate changes how quickly source time advances without changing the draft frame rate. A trimmed or split GIF can restart at the new boundary, so review animation continuity after either edit. Audio fade durations are authored with timeline handles rather than in the Inspector. Video and audio inspectors provide base volume where applicable.

Source metadata can use a native frame rate or time base different from the draft. The editor’s public timing contract is the draft’s integer composition frames; decoding chooses the best source sample for that requested time.

Audio gain path

Audio level begins with the layer’s decibel value:

base gain = 0, when dB = -60
base gain = 10^(dB / 20), otherwise
evaluated gain = base gain × fade-in multiplier × fade-out multiplier

Track mute and preview mute are monitoring/composition controls applied in addition to layer gain. A waveform is only a visualization; its height does not replace the numeric gain setting.

Media formats and MIME types

Upload acceptance is broader than a single extension list and depends on browser-reported MIME type, metadata probing, and the browser’s actual decode support.

Family	Typical examples	Important caveat
Video	MP4, WebM, QuickTime-compatible files	A recognized container may still contain a codec that the browser cannot decode
Audio	MP3, WAV, AAC/M4A, Ogg-family audio	Waveform creation and preview decode can fail independently of upload
Image	PNG, JPEG, WebP, common browser image formats	Very large dimensions increase decode and canvas memory
Animated image	GIF and supported animated formats	Duration and frame decoding depend on usable metadata

See Supported media formats for the operational upload checklist.

Remote media

Remote media needs a URL that remains readable by the browser and render path. A thumbnail URL succeeding does not prove the full-resolution asset or byte-range requests will succeed. Insert a result and verify full-resolution decoding before building dependent timing around it.

Cache layers

The timeline can reuse decoded filmstrip frames and waveform data to avoid repeating expensive work. Cache artifacts are disposable visual accelerators:

A missing cache should trigger regeneration, not change the layer’s authored values.
A stale filmstrip does not alter the evaluated video frame.
Clearing browser site data can make filmstrips and waveforms rebuild.
Export reads the actual media and draft state, not a screenshot of the timeline cache.

H.264 render participation

Layer	Included in final H.264 image	Included in final H.264 audio
Video	✓ when visible at the frame	✓ when source has audio and gain/track state permits
Audio	—	✓ when active and not effectively muted
Image / GIF	✓ when visible at the frame	—
Text / Solid / Frame / Captions	✓ when visible at the frame	—

Timeline guides, selection boxes, handles, the playhead, panel UI, waveform drawings, and filmstrips are editor chrome and are not rendered into the video.

Media workflow

Follow media discovery, upload, insertion, placement, and verification in the editor.

Media troubleshooting

Diagnose metadata, decoding, proxy, waveform, and caption-source failures.

Start here

Workspace

Core editing

Timeline

Canvas and layout

Media

Layers and inspectors

Effects and shadows

Audio

Captions

Animation and keyframes

Collaboration and recovery

Render

Reference

Troubleshooting

Acquisition and authoring

Preview and timeline behavior

Inspector capability summary

Source mapping

Audio gain path

Media formats and MIME types

Remote media

Cache layers

H.264 render participation

Media workflow

Media troubleshooting

​Acquisition and authoring

​Preview and timeline behavior

​Inspector capability summary

​Source mapping

​Audio gain path

​Media formats and MIME types

​Remote media

​Cache layers

​H.264 render participation

Media workflow

Media troubleshooting

Acquisition and authoring

Preview and timeline behavior

Inspector capability summary

Source mapping

Audio gain path

Media formats and MIME types

Remote media

Cache layers

H.264 render participation