hyperframes/docs/packages/producer.mdx

---
title: "@hyperframes/producer"
description: "Full HTML-to-video rendering pipeline with encoding, audio mixing, and Docker support."
---

The producer package combines the [engine's](/packages/engine) frame capture with FFmpeg encoding to deliver a complete HTML-to-video rendering pipeline. It supports MP4 (h264) and WebM (VP9 with alpha transparency), and handles runtime injection, readiness gates, audio mixing, and optional Docker-based deterministic rendering.

```bash
npm install @hyperframes/producer
```

## When to Use

**Use `@hyperframes/producer` when you need to:**
- Render compositions to MP4 or WebM programmatically from Node.js (e.g., in a backend service or CI pipeline)
- Build a custom rendering service with fine-grained control over the pipeline
- Run visual regression tests against golden baselines
- Benchmark render performance across different configurations

**Use a different package if you want to:**
- Render from the command line without writing code — use the [CLI](/packages/cli) (`npx hyperframes render`)
- Preview compositions in the browser — use the [CLI](/packages/cli) or [studio](/packages/studio)
- Capture frames without encoding — use the [engine](/packages/engine)
- Lint or parse composition HTML — use [core](/packages/core)

<Tip>
  If you are building a web application or script that just needs to render a video, the [CLI](/packages/cli) is the fastest path. The producer package is for when you need programmatic control inside Node.js.
</Tip>

## What It Does

The producer orchestrates the full render pipeline:

<Steps>
  <Step title="Load the composition HTML">
    Reads your `index.html` and any referenced sub-compositions.
  </Step>
  <Step title="Inject the Hyperframes runtime">
    Adds the runtime script that manages timeline seeking, clip lifecycle, and media playback.
  </Step>
  <Step title="Wait for readiness gates">
    Polls for `window.__playerReady` and `window.__renderReady` to ensure all assets (fonts, images, video) are loaded before capture begins.
  </Step>
  <Step title="Capture frames via the engine">
    Uses the [engine's](/packages/engine) BeginFrame pipeline to capture each frame as a pixel buffer.
  </Step>
  <Step title="Encode to MP4 or WebM via FFmpeg">
    Pipes frame buffers into FFmpeg with the selected quality preset. MP4 uses h264; WebM uses VP9 with alpha transparency support.
  </Step>
  <Step title="Mix audio tracks">
    Extracts audio from video clips and audio elements, applies `data-volume` and `data-media-start` offsets, and mixes them into the final MP4.
  </Step>
</Steps>

## Programmatic Usage

The producer uses a two-step API: create a render job configuration, then execute it.

```typescript
import { createRenderJob, executeRenderJob } from '@hyperframes/producer';

const job = createRenderJob({
  input: './my-video/index.html',
  output: './output.mp4',
  fps: 30,
  quality: 'standard',
});

const result = await executeRenderJob(job);
```

### Render Configuration

```typescript
import type { RenderConfig } from '@hyperframes/producer';

const config: RenderConfig = {
  fps: 30,                   // 24, 30, or 60
  quality: 'standard',       // 'draft', 'standard', or 'high'
  format: 'mp4',             // 'mp4' or 'webm' (WebM renders with transparency)
  workers: 4,                // Parallel render workers (1-8)
  useGpu: false,             // GPU-accelerated encoding
  debug: false,              // Debug logging
};
```

#### WebM with Transparency

Set `format: 'webm'` to render with a transparent background using VP9 alpha:

```typescript
const job = createRenderJob({
  fps: 30,
  quality: 'standard',
  format: 'webm',
});

await executeRenderJob(job, './my-overlay', './overlay.webm');
```

When `format: 'webm'`:
- Frames are captured as PNG (preserves alpha channel)
- Chrome's page background is set to transparent via CDP
- FFmpeg encodes with VP9 + `yuva420p` pixel format
- Audio is encoded as Opus (instead of AAC for MP4)

#### HDR Output

Set `hdr: true` to enable HDR detection. The producer probes every video and image source for BT.2020 / PQ / HLG color tagging — if any HDR source is found, the output uses H.265 10-bit BT.2020 with HDR10 static metadata. SDR-only compositions are unaffected.

```typescript
const job = createRenderJob({
  fps: 30,
  quality: 'standard',
  format: 'mp4',
  hdr: true,
});

await executeRenderJob(job, './my-video', './output.mp4');
```

When `hdr: true`:
- Sources are probed via `ffprobe`; PQ takes precedence over HLG when both are present
- HDR videos and images are extracted as 16-bit linear-light pixels and composited natively
- SDR DOM overlays are converted from sRGB → BT.2020 before being layered on top
- Output uses `libx265` with `yuv420p10le` and HDR10 mastering / content-light-level metadata
- `format` must be `'mp4'` — `'mov'` and `'webm'` fall back to SDR
- HDR `<img>` support is **still images only**; animated HDR-tagged images use only the first frame

For full details on source requirements, fallback rules, and verification, see [HDR Rendering](/guides/hdr).

### Progress Callbacks

```typescript
import type { ProgressCallback, RenderStatus } from '@hyperframes/producer';

const onProgress: ProgressCallback = (status: RenderStatus) => {
  console.log(`Status: ${status}`);
  // Statuses: "queued" | "preprocessing" | "rendering" | "encoding"
  //           | "assembling" | "complete" | "failed" | "cancelled"
};
```

### Cancellation

```typescript
import { RenderCancelledError } from '@hyperframes/producer';

try {
  await executeRenderJob(job);
} catch (err) {
  if (err instanceof RenderCancelledError) {
    console.log(`Cancelled: ${err.reason}`);
    // reason: "user_cancelled" | "timeout" | "aborted"
  }
}
```

## HTTP Server

The producer includes a built-in HTTP server for running as a rendering service:

```typescript
import { startServer } from '@hyperframes/producer/server';

await startServer({ port: 8080 });
```

### Server Endpoints

| Method | Path | Description |
|--------|------|-------------|
| `POST` | `/render` | Blocking render — returns JSON result |
| `POST` | `/render/stream` | Streaming render with Server-Sent Events |
| `POST` | `/lint` | Lint a composition for issues |
| `GET` | `/health` | Health check |
| `GET` | `/outputs/:token` | Download a rendered MP4 |

For custom server integration, use the lower-level handlers:

```typescript
import { createRenderHandlers, createProducerApp } from '@hyperframes/producer/server';

// Get individual request handlers
const handlers = createRenderHandlers(options);

// Or get a full Hono app
const app = createProducerApp(options);
```

## Docker Rendering

For deterministic output, the producer can render inside a Docker container with a pinned Chrome version and font set. This guarantees identical output across machines — critical for CI pipelines and production services.

```bash
# Via the CLI (recommended)
npx hyperframes render --docker --output output.mp4
```

<Info>
  Docker mode requires Docker to be installed and running. Run `npx hyperframes doctor` to verify your environment. See [Deterministic Rendering](/concepts/determinism) for details on what makes Docker mode deterministic.
</Info>

## Quality Presets

| Preset | Resolution | Encoding | Use Case |
|--------|-----------|----------|----------|
| `draft` | Original | Fast CRF | Quick iteration, previewing edits |
| `standard` | Original | Balanced CRF | Production renders, sharing |
| `high` | Original | High-quality CRF | Final delivery, archival |

## GPU Encoding

The producer supports hardware-accelerated encoding for faster renders:

| Platform | Encoder | Flag |
|----------|---------|------|
| NVIDIA | NVENC | Auto-detected |
| macOS | VideoToolbox | Auto-detected |
| Linux | VAAPI | Auto-detected |

GPU encoding is automatically used when available. To check your system's capabilities:

```bash
npx hyperframes doctor
```

## Additional Exports

The producer also re-exports key engine functionality for convenience:

| Export | Description |
|--------|-------------|
| `createCaptureSession()` | Create a frame capture session |
| `initializeSession()` | Initialize session with a composition |
| `captureFrame()` / `captureFrameToBuffer()` | Capture individual frames |
| `closeCaptureSession()` | Clean up a capture session |
| `getCompositionDuration()` | Get total composition duration |
| `getCapturePerfSummary()` | Get capture performance metrics |
| `createFileServer()` | Create an HTTP file server for serving assets |
| `createVideoFrameInjector()` | Create a video frame injector for page |
| `resolveConfig()` / `DEFAULT_CONFIG` | Producer configuration |
| `createConsoleLogger()` / `defaultLogger` | Logging utilities |
| `quantizeTimeToFrame()` | Convert time to frame boundary |
| `resolveRenderPaths()` | Resolve render directory paths |
| `prepareHyperframeLintBody()` / `runHyperframeLint()` | Linting utilities |

## Regression Testing

The producer includes a regression harness for comparing render output against golden baselines. This is useful for catching visual regressions when changing the runtime, engine, or rendering pipeline.

```bash
cd packages/producer

# Build the test Docker image
bun run docker:build:test

# Run regression tests (compares output against golden baselines)
bun run docker:test

# Regenerate golden baselines after intentional changes
bun run docker:test:update
```

## Benchmarking

Find optimal render settings for your hardware:

```bash
# Via the CLI
npx hyperframes benchmark

# Directly from the producer package
cd packages/producer
bun run benchmark
```

The benchmark runs several compositions with different quality and FPS settings and reports timing for each combination.

## External assets (files outside `projectDir`)

A composition can reference absolute paths to assets outside the project
directory — a local voiceover in `~/Downloads`, a shared-drive image, a
generated fixture at an absolute path. The producer handles these by:

1. **Detection.** During compilation, the HTML compiler walks every
   `[src]` / `[href]` and every `url(...)` in `<style>`. A path that
   resolves to a file outside `projectDir` is collected into an
   `externalAssets` map.
2. **Sanitised keys.** Each absolute path is converted into a safe,
   cross-platform relative key prefixed with `hf-ext/`. Windows
   drive-letter colons are stripped (`D:\foo\x.wav` → `hf-ext/D/foo/x.wav`)
   so that `path.join(compileDir, key)` stays inside the compile
   directory on every OS.
3. **Copy + rewrite.** The orchestrator copies the file under
   `<compileDir>/hf-ext/...` and the HTML is rewritten to point at the
   sanitised key. The file server then serves both project-internal and
   external assets from the same root.

The containment check uses `path.relative()` rather than a hardcoded
separator, so external assets work identically on macOS, Linux, and
Windows. See `packages/producer/src/utils/paths.ts` for the helpers.

## Related Packages

<CardGroup cols={2}>
  <Card title="CLI" icon="terminal" href="/packages/cli">
    Command-line interface that wraps the producer for rendering, previewing, and more.
  </Card>
  <Card title="Engine" icon="gear" href="/packages/engine">
    The low-level capture pipeline that the producer uses to grab frames.
  </Card>
  <Card title="Core" icon="cube" href="/packages/core">
    Types, runtime, and linter that the producer depends on.
  </Card>
  <Card title="Studio" icon="palette" href="/packages/studio">
    Visual editor for building compositions before rendering with the producer.
  </Card>
</CardGroup>