@mediaway/device

Camera, microphone, and screen capture over Mediaway's C ABI (mediaway_ffi.dll). Capture is poll-based and synchronous — frames are ready when pollFrame() returns one; it never blocks waiting for hardware.

Windows is the verified platform (Media Foundation backends). Linux camera backends compile; other platforms are not implemented yet.

Install

npm install @mediaway/device

Camera example

import { openCamera, CaptureUnavailableError, type VideoFrame } from "@mediaway/device";

const camera = await openCamera({ index: 0, timeBase: { num: 1, den: 30 } });
console.log(`camera: ${camera.width}x${camera.height}`);

const frames: Buffer[] = [];
const started = Date.now();
while (Date.now() - started < 3_000) {
  const frame = camera.pollFrame(); // VideoFrame | null — never blocks
  if (frame) frames.push(Buffer.from(frame.data)); // NV12 planes
}
await camera.close(); // joins the backend worker thread (up to one frame interval)

Handle a missing camera cleanly:

try {
  const camera = await openCamera({ index: 0, timeBase: { num: 1, den: 30 } });
  // ... record
} catch (err) {
  if (err instanceof CaptureUnavailableError) console.log("no camera here");
  else throw err;
}

Microphone

import { openMicrophone } from "@mediaway/device";

const mic = await openMicrophone({ sampleRate: 48_000, channels: 1 });
// mic.sampleRate, mic.channels
const frame = mic.pollFrame(); // AudioFrame | null — raw interleaved f32le PCM
await mic.close();

Screen capture

import { openScreenCapture } from "@mediaway/device";

const screen = await openScreenCapture({
  timeBase: { num: 1, den: 30 },
  captureCursor: true,
});
const frame = screen.pollFrame(); // VideoFrame | null
await screen.close();

API

| Function | Session | Frames | | --- | --- | --- | | openCamera({ index, timeBase }) | CameraSession (width, height, pixelFormat = "nv12") | pollFrame(): VideoFrame \| null | | openMicrophone({ sampleRate, channels }) | MicSession (sampleRate, channels) | pollFrame(): AudioFrame \| null | | openScreenCapture({ timeBase, captureCursor? }) | ScreenSession | pollFrame(): VideoFrame \| null |

Every session's close() is async (joins the backend worker thread). CaptureUnavailableError signals a missing device.

License

MIT OR Apache-2.0. Part of the Mediaway project — pre-1.0, APIs may change.