# Mix (Cross Dissolve) — effect skill for transitions

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The two shots blend through each other. The quietest transition: "time passes" or "this continues".

- **Type:** [Effect](https://varg.ai/how-to/effects.md) · [Transitions](https://varg.ai/how-to/browse/skills/transitions.md)
- **Slug:** `mix-dissolve`
- **Status:** live
- **Publisher:** HeyGen (community)
- **License:** Apache-2.0
- **Source:** https://github.com/heygen-com/hyperframes/tree/main/registry/components/fade-through
- **Works in:** Claude Code, Claude.ai, Codex, Cursor, OpenClaw, Gemini CLI, Any MCP client, varg Studio
- **Requires:** ffmpeg, HyperFrames (npx hyperframes), Remotion, CapCut (by hand)
- **Cost:** Free — the take renders locally; generated footage, if any, bills by the model

## What it does

Built on [Fade Through](https://github.com/heygen-com/hyperframes/tree/main/registry/components/fade-through) by HeyGen (HyperFrames), Apache-2.0. The write-up and recipes below are varg's.

A fades out while B fades in over the same frames; halfway both are at 50%.

**When:** Time passing, calm brand and wellness pieces, slideshow photos, soft scene changes.

**Watch out:** Mixing between two busy shots makes mud; never use it to hide a weak cut in fast edits.

**Timing:** 0.4–1.0 s (CapCut Mix default 1.0 s, a short Mix 0.47 s), linear or ease-in-out

**Also called:** Mix, Dissolve, crossfade, cross dissolve, fade

### In FFmpeg

Same size/fps/pixel format on both inputs (see the Normalize card). offset = duration(A) - T = 5.0 - 0.5 = 4.5.
```bash
ffmpeg -i a.mp4 -i b.mp4 -filter_complex \
"[0:v]fps=30,settb=AVTB,format=yuv420p[a];[1:v]fps=30,settb=AVTB,format=yuv420p[b];\
[a][b]xfade=transition=fade:duration=0.5:offset=4.5[v];\
[0:a][1:a]acrossfade=d=0.5[au]" \
  -map "[v]" -map "[au]" -c:v libx264 -crf 18 -c:a aac out.mp4
```
`dissolve` is a different, dithered (noisy) dissolve; `fadefast`/`fadeslow` change the curve.

### In HyperFrames

Shader `cross-warp-morph` from `@hyperframes/shader-transitions` placed at the cut (t = 4 s):
```html
<div id="s1" class="scene" style="background:#0a0a0a"><video src="a.mp4" muted playsinline></video></div>
<div id="s2" class="scene" style="background:#0a0a0a"><video src="b.mp4" muted playsinline></video></div>
<script src="https://cdn.jsdelivr.net/npm/@hyperframes/shader-transitions/dist/index.global.js"></script>
<script>
  const tl = HyperShader.init({ bgColor: "#0a0a0a", scenes: ["s1", "s2"],
    transitions: [{ time: 4, shader: "cross-warp-morph", duration: 0.8 }] });
  window.__timelines = window.__timelines || {}; window.__timelines["main"] = tl;
</script>
```
Each `.scene` needs an explicit background-color equal to `bgColor`.
Plain CSS crossfade: omit `shader` in that transition entry, or overlap two clips by 0.5 s and tween opacity (see the HyperFrames scene transition card).

### In Remotion

```tsx
import {TransitionSeries, linearTiming, springTiming} from '@remotion/transitions';
import {fade} from '@remotion/transitions/fade';

<TransitionSeries>
  <TransitionSeries.Sequence durationInFrames={90}><ShotA /></TransitionSeries.Sequence>
  <TransitionSeries.Transition presentation={fade()} timing={linearTiming({durationInFrames: 15})} />
  <TransitionSeries.Sequence durationInFrames={90}><ShotB /></TransitionSeries.Sequence>
</TransitionSeries>
```
Total = 90 + 90 - 15 frames: the transition overlaps the two shots.

### In CapCut

Transitions tab → Basic / Overlay → Mix, Dissolve, Dissolve II/III. Desktop: drag the tile onto the cut between two clips and set Duration in the right panel ("Apply to all" reuses it on every cut). Mobile: tap the small white square between clips, pick the transition, drag the duration slider, tap ✓. Tab labels and placement change between versions and regions.

### Ready-made components

- [Fade Through](https://skills.varg.ai/component/hf.fade-through/) (hyperframes): npx hyperframes add fade-through
- [Dissolve Transitions](https://skills.varg.ai/component/hf.transitions-dissolve/) (hyperframes): npx hyperframes add transitions-dissolve
- [Cross Warp Morph](https://skills.varg.ai/component/hf.cross-warp-morph/) (hyperframes): npx hyperframes add cross-warp-morph
- [Dreamy](https://skills.varg.ai/component/glt.dreamy/) (gl-transitions): npm install gl-transitions

### Where this comes from

- [FFmpeg filters: xfade](https://ffmpeg.org/ffmpeg-filters.html#xfade)
- [Remotion: presentations](https://www.remotion.dev/docs/transitions/presentations)
- [HyperFrames: @hyperframes/shader-transitions](https://hyperframes.heygen.com/packages/shader-transitions)
- [CapCut Help: transitions](https://www.capcut.com/help/transitions-in-capcut)
- [CapCut: transition categories](https://capcut.com/resource/add-video-transition-online)
- [CapCut transition names + default durations (VectCut metadata)](https://github.com/sun-guannan/VectCutAPI/blob/main/pyJianYingDraft/metadata/capcut_transition_meta.py)

## Use when

- Time passing, calm brand and wellness pieces, slideshow photos, soft scene changes.

## Not for

- Mixing between two busy shots makes mud; never use it to hide a weak cut in fast edits.

## Install

- Claude Code: `claude plugin marketplace add vargHQ/skills && claude plugin install varg@varg`
- Codex: `npx skills add vargHQ/skills --skill varg-video-edit-library -a codex -y`
- Cursor: `npx skills add vargHQ/skills --skill varg-video-edit-library -a cursor -y`

## Example output

https://s3.varg.ai/how-to/previews/22b4c9523412/take-mix-dissolve.mp4 — fade between two shots, with the timeline strip of the edit. Footage: Big Buck Bunny (2008), (c) copyright 2008, Blender Foundation | www.bigbuckbunny.org, CC BY 3.0; WING IT! (2023), Blender Studio | studio.blender.org, CC BY 4.0. (credit: Rendered by varg · Big Buck Bunny (2008) + WING IT! (2023))

## More transitions skills

- [editly](https://varg.ai/how-to/skills/editly.md): Declarative JSON5 video editing CLI/API: clips, titles, transitions, audio mixing, rendered with ffmpeg.
- [Dip to Black](https://varg.ai/how-to/skills/black-fade.md): A fades to black, then B fades up. Marks the end of a section or a bigger jump in time.
- [White Flash](https://varg.ai/how-to/skills/white-flash.md): The frame blows out to white for a moment and opens on the next shot. Energy, memory or a camera snap.
- [Pull In (Zoom In)](https://varg.ai/how-to/skills/pull-in-zoom.md): The camera rushes into shot A and lands, still moving forward, in shot B. The signature short-form transition.
- [Pull Out (Zoom Out)](https://varg.ai/how-to/skills/pull-out-zoom.md): The camera jerks backwards out of shot A and keeps pulling back as shot B settles in.
- [Zoom Blur](https://varg.ai/how-to/skills/zoom-blur.md): Both shots smear into a radial zoom blur that bursts open on the next shot.

## Run the generation on varg

varg is one API key for the models these skills drive — Seedance 2.5, Kling 4, Veo 3.1, Wan 3, Nano Banana 2.1, GPT Image 2.5, ElevenLabs v4 and 200+ more — billed in credits, with a cost estimate before anything runs.

- Claude Code: `claude plugin marketplace add vargHQ/skills && claude plugin install varg@varg` (skill + hosted MCP)
- Codex, Cursor, Gemini CLI, OpenClaw: `npx skills add vargHQ/skills --skill varg-ai -a <agent> -y`
- Grok and any agent that reads SKILL.md: `npx skills add vargHQ/skills --skill varg-ai`, or point it at the skill's SKILL.md
- Claude.ai, ChatGPT, any MCP client: connect `https://mcp.varg.ai/mcp`
- API key: https://varg.ai/dashboard/api · Model specs: https://varg.ai/models/llms.txt