Table of Contents
- Overview
- Required TodoWrite Items
- Manifest Format
- Manifest Schema
- Step-by-Step Process
- 1. Parse Manifest File
- 2. Validate Component Outputs
- 3. Execute FFmpeg Composition
- 4. Verify Combined Output
- FFmpeg Composition Commands
- Vertical Stacking
- Horizontal Stacking
- Sequential Concatenation
- Grid Layout (2x2)
- With Background Color
- Layout Options
- Layout Option Details
- Example Compositions
- Terminal + Browser Tutorial
- Side-by-Side Comparison
- Picture-in-Picture
- Exit Criteria
Media Composition Skill
Combine multiple media assets (GIFs, videos, images) into composite outputs for detailed tutorials and documentation.
When To Use
- Combining multiple media outputs into compositions
- Creating composite demos from terminal and browser recordings
When NOT To Use
- Single-format output that does not need composition
- Simple terminal recordings - use scry:vhs-recording directly
Overview
This skill orchestrates the combination of separately generated media assets into unified outputs. It reads manifest files that define components and their composition rules, validates all inputs exist, and executes FFmpeg commands to produce the final composite media.
Required TodoWrite Items
- Parse composition manifest file
- Validate all component outputs exist
- Determine composition layout and parameters
- Execute FFmpeg composition command
- Verify combined output file created
- Report composition metrics (file size, dimensions)
Verification: Run the command with --help flag to verify availability.
Manifest Format
Manifests define the components to combine and how to arrange them:
# Example manifest: tutorials/mcp.manifest.yaml
name: mcp
title: "MCP Server Integration"
components:
- type: tape
source: mcp.tape
output: assets/gifs/mcp-terminal.gif
- type: playwright
source: browser/mcp-browser.spec.ts
output: assets/gifs/mcp-browser.gif
requires:
- "skrills serve"
combine:
output: assets/gifs/mcp-combined.gif
layout: vertical
options:
padding: 10
background: "#1a1a2e"
Verification: Run the command with --help flag to verify availability.
Manifest Schema
| Field | Type | Required | Description |
|-------|------|----------|-------------|
| name | string | Yes | Identifier for the composition |
| title | string | No | Human-readable title |
| components | array | Yes | List of media components to combine |
| components[].type | string | Yes | Source type: tape, playwright, static |
| components[].source | string | Yes | Path to source file |
| components[].output | string | Yes | Path to generated output |
| components[].requires | array | No | Commands to run before generation |
| combine.output | string | Yes | Path for combined output |
| combine.layout | string | Yes | Layout mode (see table below) |
| combine.options | object | No | Layout-specific options |
Step-by-Step Process
1. Parse Manifest File
# Read and validate manifest structure
yq eval '.' manifest.yaml
# Extract component outputs
yq eval '.components[].output' manifest.yaml
Verification: Run the command with --help flag to verify availability.
2. Validate Component Outputs
# Check all required files exist
for output in $(yq eval '.components[].output' manifest.yaml); do
if [[ ! -f "$output" ]]; then
echo "ERROR: Missing component: $output"
exit 1
fi
done
Verification: Run the command with --help flag to verify availability.
3. Execute FFmpeg Composition
Based on the layout specified in the manifest, execute the appropriate FFmpeg command.
4. Verify Combined Output
# Verify output exists and has content
if [[ -f "$output" && -s "$output" ]]; then
echo "Composition successful: $output"
ls -lh "$output"
else
echo "ERROR: Composition failed"
exit 1
fi
Verification: Run the command with --help flag to verify availability.
FFmpeg Composition Commands
Vertical Stacking
Stack GIFs/videos top to bottom:
ffmpeg -i top.gif -i bottom.gif \
-filter_complex "[0:v][1:v]vstack=inputs=2" \
-y output.gif
Verification: Run the command with --help flag to verify availability.
With padding between:
ffmpeg -i top.gif -i bottom.gif \
-filter_complex "[0:v]pad=iw:ih+10:0:0:color=black[top];[top][1:v]vstack=inputs=2" \
-y output.gif
Verification: Run the command with --help flag to verify availability.
Horizontal Stacking
Stack GIFs/videos side by side:
ffmpeg -i left.gif -i right.gif \
-filter_complex "[0:v][1:v]hstack=inputs=2" \
-y output.gif
Verification: Run the command with --help flag to verify availability.
Sequential Concatenation
Play GIFs/videos one after another:
# Create concat list file
cat > concat_list.txt << EOF
file 'first.gif'
file 'second.gif'
file 'third.gif'
EOF
# Concatenate
ffmpeg -f concat -safe 0 -i concat_list.txt \
-y output.gif
Verification: Run the command with --help flag to verify availability.
Grid Layout (2x2)
ffmpeg -i tl.gif -i tr.gif -i bl.gif -i br.gif \
-filter_complex "[0:v][1:v]hstack=inputs=2[top];[2:v][3:v]hstack=inputs=2[bottom];[top][bottom]vstack=inputs=2" \
-y output.gif
Verification: Run the command with --help flag to verify availability.
With Background Color
ffmpeg -i top.gif -i bottom.gif \
-filter_complex "color=c=#1a1a2e:s=800x600[bg];[bg][0:v]overlay=0:0[tmp];[tmp][1:v]overlay=0:300" \
-y output.gif
Verification: Run the command with --help flag to verify availability.
Layout Options
| Layout | Description | Options |
|--------|-------------|---------|
| vertical | Stack top to bottom | padding, background, align |
| horizontal | Stack left to right | padding, background, align |
| sequential | Play in order | transition, duration |
| grid | N x M grid arrangement | rows, cols, padding |
| overlay | Layer on top of each other | position, opacity |
| pip | Picture-in-picture | corner, scale, margin |
Layout Option Details
| Option | Type | Default | Description |
|--------|------|---------|-------------|
| padding | int | 0 | Pixels between components |
| background | string | "black" | Background color (hex or name) |
| align | string | "center" | Alignment: left, center, right |
| transition | string | "none" | Transition type: fade, wipe, none |
| scale | float | 0.25 | Scale factor for PiP |
| corner | string | "br" | PiP corner: tl, tr, bl, br |
Example Compositions
Terminal + Browser Tutorial
name: plugin-demo
components:
- type: tape
source: demo.tape
output: terminal.gif
- type: playwright
source: browser.spec.ts
output: browser.gif
combine:
output: demo-combined.gif
layout: vertical
options:
padding: 5
background: "#0d1117"
Verification: Run the command with --help flag to verify availability.
Side-by-Side Comparison
name: before-after
components:
- type: static
source: before.gif
output: before.gif
- type: static
source: after.gif
output: after.gif
combine:
output: comparison.gif
layout: horizontal
options:
padding: 10
Verification: Run the command with --help flag to verify availability.
Picture-in-Picture
name: pip-demo
components:
- type: tape
source: main.tape
output: main.gif
- type: playwright
source: overlay.spec.ts
output: overlay.gif
combine:
output: pip-demo.gif
layout: pip
options:
corner: br
scale: 0.3
margin: 20
Verification: Run the command with --help flag to verify availability.
Exit Criteria
- [ ] Manifest file parsed successfully
- [ ] All component outputs validated as existing
- [ ] FFmpeg composition command executed without errors
- [ ] Combined output file exists and has non-zero size
- [ ] Output dimensions and duration logged
- [ ] Temporary files cleaned up
Troubleshooting
Common Issues
Command not found Ensure all dependencies are installed and in PATH
Permission errors Check file permissions and run with appropriate privileges
Unexpected behavior
Enable verbose logging with --verbose flag