# cp949/react-webcam architecture

> Architecture diagram of the GitHub repository cp949/react-webcam, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-11-15). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/cp949/react-webcam
- Repository: https://github.com/cp949/react-webcam

## Overview

`@cp949/react-webcam` is a React webcam component library. Its main runtime flow observes the video element, derives camera constraints, requests and manages a media stream, binds it to video playback, and renders webcam state and controls; the ref controller also exposes snapshot and playback actions. The README mentions a Next.js demo, but its source is absent from this tree, so it is not mapped. Relationships below follow the excerpts and SOURCE INDEX; unsampled functionality is represented only where documented or indexed.

Main entry points: [`packages/react-webcam/src/hooks/useWebcamController.ts`](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useWebcamController.ts) (Webcam Controller), [`packages/react-webcam/src/Webcam.tsx`](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/Webcam.tsx) (Webcam Component), [`packages/react-webcam/src/hooks/useElementMediaConstraints.ts`](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useElementMediaConstraints.ts) (Constraint Sizing), [`packages/react-webcam/src/hooks/useWebcamStreamLifecycle.ts`](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useWebcamStreamLifecycle.ts) (Stream Lifecycle)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_ui["Component UI"]
  node_webcam["Webcam Component<br/>[Webcam.tsx]"]
  node_controls["Camera Controls"]
end

subgraph group_control["Webcam Control"]
  node_controller["Webcam Controller"]
  node_constraints["Constraint Sizing"]
  node_bindings["Video Bindings"]
  node_lifecycle["Stream Lifecycle"]
  node_state["State Mapping"]
  node_constraint_builder["Constraint Builder"]
  node_size_observer["Element Size Observer"]
  node_snapshot["Canvas Snapshot"]
end

subgraph group_media["Media Access"]
  node_media_adapter["Media Device Adapter<br/>[media-devices.ts]"]
  node_device_listing["Device Listing"]
end

subgraph group_api["Public API"]
  node_controller_types["Controller Types"]
  node_webcam_types["Webcam Types<br/>[webcam-types.ts]"]
end

node_user(("Application"))
node_browser_media["Browser Media APIs"]

node_user -->|"renders"| node_webcam
node_webcam -->|"uses"| node_controller
node_webcam -->|"renders"| node_controls
node_controller -->|"derives constraints"| node_constraints
node_controller -->|"manages stream"| node_lifecycle
node_controller -->|"binds video"| node_bindings
node_controller -->|"maps state"| node_state
node_controller -->|"captures frame"| node_snapshot
node_constraints -->|"builds constraints"| node_constraint_builder
node_constraints -->|"observes size"| node_size_observer
node_lifecycle -->|"requests and stops"| node_media_adapter
node_lifecycle -->|"maps errors"| node_state
node_device_listing -->|"lists devices"| node_media_adapter
node_media_adapter -->|"calls"| node_browser_media
node_controller -->|"implements contract"| node_controller_types
node_controller_types -->|"uses options"| node_webcam_types
node_constraint_builder -->|"uses options"| node_webcam_types

click node_webcam "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/Webcam.tsx"
click node_controls "https://github.com/cp949/react-webcam/tree/main/packages/react-webcam/src/components"
click node_controller "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useWebcamController.ts"
click node_constraints "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useElementMediaConstraints.ts"
click node_bindings "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useVideoElementBindings.ts"
click node_lifecycle "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useWebcamStreamLifecycle.ts"
click node_state "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/webcam-controller-state.ts"
click node_constraint_builder "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/build-media-stream-constraints.ts"
click node_size_observer "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/observe-element-size.ts"
click node_snapshot "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/snapshot-to-canvas.ts"
click node_media_adapter "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/media-devices.ts"
click node_device_listing "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/list-media-devices.ts"
click node_controller_types "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/types/webcam-controller.ts"
click node_webcam_types "https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/webcam-types.ts"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_webcam,node_controls,node_browser_media toneBlue
class node_controller,node_constraints,node_bindings,node_lifecycle,node_state,node_constraint_builder,node_size_observer,node_snapshot toneAmber
class node_media_adapter,node_device_listing toneMint
class node_controller_types,node_webcam_types toneRose
class node_user toneIndigo
```

## Components

### Component UI

- [Webcam Component](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/Webcam.tsx): `packages/react-webcam/src/Webcam.tsx`
- [Camera Controls](https://github.com/cp949/react-webcam/tree/main/packages/react-webcam/src/components): `packages/react-webcam/src/components`

### Webcam Control

- [Webcam Controller](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useWebcamController.ts): `packages/react-webcam/src/hooks/useWebcamController.ts`
- [Constraint Sizing](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useElementMediaConstraints.ts): `packages/react-webcam/src/hooks/useElementMediaConstraints.ts`
- [Video Bindings](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useVideoElementBindings.ts): `packages/react-webcam/src/hooks/useVideoElementBindings.ts`
- [Stream Lifecycle](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/hooks/useWebcamStreamLifecycle.ts): `packages/react-webcam/src/hooks/useWebcamStreamLifecycle.ts`
- [State Mapping](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/webcam-controller-state.ts): `packages/react-webcam/src/utils/webcam-controller-state.ts`
- [Constraint Builder](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/build-media-stream-constraints.ts): `packages/react-webcam/src/utils/build-media-stream-constraints.ts`
- [Element Size Observer](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/observe-element-size.ts): `packages/react-webcam/src/utils/observe-element-size.ts`
- [Canvas Snapshot](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/snapshot-to-canvas.ts): `packages/react-webcam/src/utils/snapshot-to-canvas.ts`

### Media Access

- [Media Device Adapter](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/utils/media-devices.ts): `packages/react-webcam/src/utils/media-devices.ts`
- [Device Listing](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/list-media-devices.ts): `packages/react-webcam/src/list-media-devices.ts`

### Public API

- [Controller Types](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/types/webcam-controller.ts): `packages/react-webcam/src/types/webcam-controller.ts`
- [Webcam Types](https://github.com/cp949/react-webcam/blob/main/packages/react-webcam/src/webcam-types.ts): `packages/react-webcam/src/webcam-types.ts`

### Other components

- **Application**
- **Browser Media APIs**

## Connections

- Application → Webcam Component: renders (evidence: `README.md`)
- Webcam Component → Webcam Controller: uses (evidence: `packages/react-webcam/src/Webcam.tsx`)
- Webcam Component → Camera Controls: renders (evidence: `packages/react-webcam/src/Webcam.tsx`)
- Webcam Controller → Constraint Sizing: derives constraints (evidence: `packages/react-webcam/src/hooks/useWebcamController.ts`)
- Webcam Controller → Stream Lifecycle: manages stream (evidence: `packages/react-webcam/src/hooks/useWebcamController.ts`)
- Webcam Controller → Video Bindings: binds video (evidence: `packages/react-webcam/src/hooks/useWebcamController.ts`)
- Webcam Controller → State Mapping: maps state (evidence: `packages/react-webcam/src/hooks/useWebcamController.ts`)
- Webcam Controller → Canvas Snapshot: captures frame (evidence: `packages/react-webcam/src/hooks/useWebcamController.ts`)
- Constraint Sizing → Constraint Builder: builds constraints (evidence: `packages/react-webcam/src/hooks/useElementMediaConstraints.ts`)
- Constraint Sizing → Element Size Observer: observes size (evidence: `packages/react-webcam/src/hooks/useElementMediaConstraints.ts`)
- Stream Lifecycle → Media Device Adapter: requests and stops (evidence: `packages/react-webcam/src/hooks/useWebcamStreamLifecycle.ts`)
- Stream Lifecycle → State Mapping: maps errors (evidence: `packages/react-webcam/src/hooks/useWebcamStreamLifecycle.ts`)
- Device Listing → Media Device Adapter: lists devices (evidence: `packages/react-webcam/src/list-media-devices.ts`)
- Media Device Adapter → Browser Media APIs: calls (evidence: `packages/react-webcam/src/utils/media-devices.ts`)
- Webcam Controller → Controller Types: implements contract (evidence: `packages/react-webcam/src/hooks/useWebcamController.ts`)
- Controller Types → Webcam Types: uses options (evidence: `packages/react-webcam/src/types/webcam-controller.ts`)
- Constraint Builder → Webcam Types: uses options (evidence: `packages/react-webcam/src/utils/build-media-stream-constraints.ts`)