Virtual Webcam & MediaStream Injection

📹 Virtual Webcam & MediaStream Injection

Automating websites that require webcam access (such as video conferencing, KYC identity verification, avatar onboarding, and WebRTC applications) is notoriously difficult in traditional automation setups.

Bflow includes a built-in CDP Virtual Webcam & MediaStream Injection Engine that intercepts navigator.mediaDevices.getUserMedia and navigator.mediaDevices.enumerateDevices to feed custom video streams directly to the webpage.

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⚡ Key Capabilities

• Automated Virtual Device Registration: Registers a cdp-virtual-webcam device labeled “CDP Virtual Webcam (HD)”.
• Synthetic 30 FPS Test Pattern: Draws an animated test pattern with a real-time UTC timestamp, perfect for verifying WebRTC streaming latency and FPS.
• Local Video File Feed: Loop any local .mp4 or .webm video file as your virtual camera input.
• Remote Video URL Stream: Stream live or hosted video directly from any public or CORS-enabled URL.
• In-Page HUD Webcam Modal: Switch video feeds interactively during a recording session.

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🎛️ Controlling Virtual Webcam from the In-Page HUD

During visual recording:

1. Click the 📹 Webcam button in the floating HUD toolbar.
2. The Virtual Webcam Controller Modal will display the current active feed status.
3. Select your desired input source:
   • Synthetic Test Pattern: Generates a 640x480 @ 30 FPS animated vector canvas with moving markers and UTC clock.
   • Upload Local Video File: Choose a video file from your hard drive to loop continuously.
   • Remote Video URL: Input an https://... link to a video file.
4. Click Apply Feed. The webpage’s <video> elements will immediately receive the virtual media stream.

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💻 Programmatic JavaScript API

Inside page evaluations or test scripts, you can interact with window.__cdpVirtualWebcam:

// Switch to synthetic test pattern
window.__cdpVirtualWebcam.setPattern();

// Switch to remote video URL
await window.__cdpVirtualWebcam.setVideoUrl("https://example.com/sample-webcam-feed.mp4");

// Clear virtual stream
window.__cdpVirtualWebcam.clear();

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🧪 Testing WebRTC Applications

When testing video calling applications (Google Meet, Zoom web client, WebRTC peer-to-peer):

// Test verifying virtual webcam interception
const stream = await navigator.mediaDevices.getUserMedia({ video: true });
const videoTrack = stream.getVideoTracks()[0];

console.log(videoTrack.label); // "CDP Virtual Webcam (HD)"

[!TIP] The virtual webcam is fully sandboxed within your Chrome CDP session, requiring no third-party OBS virtual camera drivers or OS kernel extensions.