Screen Sharing

This guide covers screen sharing (desktop sharing) implementation using lib-jitsi-meet, including display capture, audio sharing, and screen-specific configurations.

Overview

Screen sharing in lib-jitsi-meet uses the getDisplayMedia API and provides cross-platform support for:

Full desktop sharing: Share entire screen
Window sharing: Share specific application window
Tab sharing: Share browser tab (Chromium-based browsers)
System audio: Capture system audio along with screen (Chrome 104+)

Check if screen sharing is supported

if (!JitsiMeetJS.isDesktopSharingEnabled()) {
    console.error('Screen sharing not supported');
    return;
}

Request screen sharing

JitsiMeetJS.createLocalTracks({
    devices: ['desktop'],
    desktopSharingFrameRate: {
        min: 5,
        max: 30
    }
}).then(tracks => {
    const desktopTrack = tracks[0];
    console.log('Screen sharing track created');
    
    // Add to conference
    conference.addTrack(desktopTrack);
}).catch(error => {
    if (error.name === 'gum.screensharing_user_canceled') {
        console.log('User canceled screen sharing');
    } else {
        console.error('Screen sharing error:', error);
    }
});

Configuration Options

Frame Rate Settings

const options = {
    devices: ['desktop'],
    
    // Frame rate configuration
    desktopSharingFrameRate: {
        min: 5,    // Minimum fps
        max: 30    // Maximum fps (higher for motion, lower for static content)
    }
};

// Default frame rate is 5 fps (SS_DEFAULT_FRAME_RATE)
JitsiMeetJS.createLocalTracks(options);

Resolution Settings

const options = {
    devices: ['desktop'],
    
    // Resolution constraints
    desktopSharingResolution: {
        width: {
            min: 640,
            max: 1920
        },
        height: {
            min: 480,
            max: 1080
        }
    }
};

Advanced Settings

const options = {
    devices: ['desktop'],
    
    // Screen share specific settings
    screenShareSettings: {
        // Prefer current tab in picker (Chrome 94+)
        desktopPreferCurrentTab: false,
        
        // System audio option (Chrome 105+)
        // 'include', 'exclude', or undefined
        desktopSystemAudio: 'include',
        
        // Allow seamless tab switching (Chrome 107+)
        // 'include', 'exclude', or undefined  
        desktopSurfaceSwitching: 'include',
        
        // Preferred display surface
        // 'monitor', 'window', 'browser', or undefined
        desktopDisplaySurface: 'monitor',
        
        // Self browser surface option (Chrome 112+)
        // 'include', 'exclude', or undefined
        desktopSelfBrowserSurface: 'exclude'
    },
    
    // Electron-specific: source types to show in picker
    desktopSharingSources: ['screen', 'window']
};

Capture System Audio (Chrome 104+)

const options = {
    devices: ['desktop'],
    screenShareSettings: {
        desktopSystemAudio: 'include'
    }
};

JitsiMeetJS.createLocalTracks(options).then(tracks => {
    tracks.forEach(track => {
        if (track.getType() === 'video') {
            console.log('Desktop video track');
        } else if (track.getType() === 'audio') {
            console.log('System audio track');
        }
        conference.addTrack(track);
    });
});

// Electron requires special handling for audio
const options = {
    devices: ['desktop'],
    desktopSharingSources: ['screen'], // Audio only works with 'screen'
    audioQuality: {
        stereo: true,
        autoGainControl: false,
        echoCancellation: false,
        noiseSuppression: false
    }
};

Audio Quality Settings

const audioQuality = {
    // Enable stereo for better system audio
    stereo: true,
    
    // Disable processing for system audio
    autoGainControl: false,
    echoCancellation: false,
    noiseSuppression: false,
    
    // Channel count
    channelCount: 2
};

const options = {
    devices: ['desktop'],
    audioQuality,
    screenShareSettings: {
        desktopSystemAudio: 'include'
    }
};

// Check if track is screen share
if (track.getVideoType() === 'desktop') {
    console.log('This is a screen share track');
}

// Get source type
const sourceType = track.sourceType; // 'screen', 'window', 'browser', etc.
const sourceId = track.sourceId;

Handle Track Ended

Screen share tracks automatically end when user stops sharing:

desktopTrack.addEventListener(
    JitsiMeetJS.events.track.LOCAL_TRACK_STOPPED,
    () => {
        console.log('Screen sharing stopped');
        
        // Remove from conference
        conference.removeTrack(desktopTrack);
        
        // Dispose track
        desktopTrack.dispose();
        
        // Update UI
        updateScreenShareButton(false);
    }
);

function stopScreenShare() {
    if (desktopTrack) {
        conference.removeTrack(desktopTrack).then(() => {
            desktopTrack.dispose();
            desktopTrack = null;
            console.log('Screen sharing stopped');
        });
    }
}

Content Hint

Optimize encoding based on content type:

// The library automatically sets contentHint based on frame rate
// High fps (>5): 'motion' - optimized for video content
// Low fps (≤5): 'detail' - optimized for text/images

// Manual override (if needed)
const mediaStreamTrack = desktopTrack.track;
if ('contentHint' in mediaStreamTrack) {
    // For presentations/documents
    mediaStreamTrack.contentHint = 'detail';
    
    // For video playback
    mediaStreamTrack.contentHint = 'motion';
    
    // For mixed content
    mediaStreamTrack.contentHint = 'text';
}

Platform-Specific Implementation

Chrome/Chromium

const options = {
    devices: ['desktop'],
    desktopSharingFrameRate: { min: 5, max: 30 },
    screenShareSettings: {
        desktopSystemAudio: 'include',
        desktopSurfaceSwitching: 'include',
        desktopPreferCurrentTab: false,
        desktopSelfBrowserSurface: 'exclude'
    }
};

// For older Chrome versions without getDisplayMedia
// Uses chrome.desktopCapture extension API
// Requires browser extension

Firefox

const options = {
    devices: ['desktop'],
    desktopSharingFrameRate: { min: 5, max: 30 },
    // Firefox supports basic getDisplayMedia
    // No system audio support
};

Safari

const options = {
    devices: ['desktop'],
    desktopSharingFrameRate: { min: 5, max: 30 },
    screenShareSettings: {
        // Safari supports displaySurface preference
        desktopDisplaySurface: 'monitor'
    }
};

Electron

const options = {
    devices: ['desktop'],
    
    // Source types to show in picker
    desktopSharingSources: ['screen', 'window'],
    
    // Frame rate and resolution
    desktopSharingFrameRate: { min: 5, max: 30 },
    desktopSharingResolution: {
        width: { max: 1920 },
        height: { max: 1080 }
    }
};

// Electron uses custom desktop picker
// Configured via JitsiMeetScreenObtainer.openDesktopPicker

Advanced Use Cases

async function switchToScreenShare() {
    try {
        // Create screen share track
        const [desktopTrack] = await JitsiMeetJS.createLocalTracks({
            devices: ['desktop'],
            desktopSharingFrameRate: { min: 5, max: 30 }
        });
        
        // Find existing video track
        const cameraTrack = localTracks.find(
            t => t.getType() === 'video' && t.getVideoType() === 'camera'
        );
        
        if (cameraTrack) {
            // Replace camera with screen share
            await conference.replaceTrack(cameraTrack, desktopTrack);
            cameraTrack.dispose();
            
            // Update tracks array
            const index = localTracks.indexOf(cameraTrack);
            localTracks[index] = desktopTrack;
        } else {
            // Just add screen share
            await conference.addTrack(desktopTrack);
            localTracks.push(desktopTrack);
        }
        
        // Handle track stopped
        desktopTrack.addEventListener(
            JitsiMeetJS.events.track.LOCAL_TRACK_STOPPED,
            () => switchBackToCamera()
        );
    } catch (error) {
        console.error('Failed to share screen:', error);
    }
}

async function switchBackToCamera() {
    const [cameraTrack] = await JitsiMeetJS.createLocalTracks({
        devices: ['video']
    });
    
    const desktopTrack = localTracks.find(
        t => t.getType() === 'video' && t.getVideoType() === 'desktop'
    );
    
    if (desktopTrack) {
        await conference.replaceTrack(desktopTrack, cameraTrack);
        desktopTrack.dispose();
        
        const index = localTracks.indexOf(desktopTrack);
        localTracks[index] = cameraTrack;
    }
}

async function shareScreenAndCamera() {
    // Note: Check browser support for multiple video tracks
    const [desktopTrack] = await JitsiMeetJS.createLocalTracks({
        devices: ['desktop'],
        desktopSharingFrameRate: { min: 5, max: 30 }
    });
    
    // Add as second video track
    await conference.addTrack(desktopTrack);
    localTracks.push(desktopTrack);
    
    // Both camera and screen share are now active
    console.log('Sharing camera and screen');
}

Dynamic Frame Rate Adjustment

// Adjust frame rate based on content
function setScreenShareFrameRate(maxFps) {
    // Set globally for future screen shares
    JitsiMeetJS.setDesktopSharingFrameRate(maxFps);
    
    // Or apply to existing track
    if (desktopTrack) {
        const track = desktopTrack.track;
        track.applyConstraints({
            frameRate: { max: maxFps, min: 5 }
        }).then(() => {
            console.log('Frame rate updated to', maxFps);
        });
    }
}

// Use lower fps for presentations
setScreenShareFrameRate(5);

// Use higher fps for video playback
setScreenShareFrameRate(30);

Error Handling

JitsiMeetJS.createLocalTracks({ devices: ['desktop'] })
    .then(tracks => {
        // Success
    })
    .catch(error => {
        switch(error.name) {
            case 'gum.screensharing_user_canceled':
                console.log('User canceled screen sharing');
                break;
                
            case 'gum.permission_denied':
                console.error('Screen sharing permission denied');
                break;
                
            case 'gum.screensharing_not_supported':
                console.error('Screen sharing not supported');
                break;
                
            case 'gum.electron_desktop_picker_not_found':
                console.error('Electron desktop picker not available');
                break;
                
            case 'gum.electron_desktop_picker_error':
                console.error('Electron desktop picker error');
                break;
                
            default:
                console.error('Screen sharing error:', error);
        }
    });

Best Practices

Optimize frame rate for content type

Use low frame rates (5 fps) for static content like presentations and documents. Use higher frame rates (15-30 fps) for video playback or animations.

// Static content
desktopSharingFrameRate: { min: 5, max: 5 }

// Video content
desktopSharingFrameRate: { min: 15, max: 30 }

Handle track stopped event

Always listen for the LOCAL_TRACK_STOPPED event to update UI when user stops sharing:

desktopTrack.addEventListener(
    JitsiMeetJS.events.track.LOCAL_TRACK_STOPPED,
    handleScreenShareStopped
);

Check browser capabilities

const supportsSystemAudio = 
    JitsiMeetJS.browser.isChromiumBased() && 
    JitsiMeetJS.browser.isEngineVersionGreaterThan(104);

if (supportsSystemAudio) {
    // Enable system audio option
}

Get Started

Core Concepts

Guides

Advanced

Overview

Configuration Options

Frame Rate Settings

Resolution Settings

Advanced Settings

Capture System Audio (Chrome 104+)

Audio Quality Settings

Handle Track Ended

Content Hint

Platform-Specific Implementation

Chrome/Chromium

Firefox

Safari

Electron

Advanced Use Cases

Dynamic Frame Rate Adjustment

Error Handling

Best Practices

Next Steps

Audio/Video Quality

Recording

​Overview

​Creating a Screen Share Track

​Configuration Options

​Frame Rate Settings

​Resolution Settings

​Advanced Settings

​Screen Sharing with Audio

​Capture System Audio (Chrome 104+)

​Audio Quality Settings

​Managing Screen Share Tracks

​Detect Screen Share

​Handle Track Ended

​Stop Screen Sharing Programmatically

​Content Hint

​Platform-Specific Implementation

​Chrome/Chromium

​Firefox

​Safari

​Electron

​Advanced Use Cases

​Replace Camera with Screen Share

​Share Camera and Screen Simultaneously

​Dynamic Frame Rate Adjustment

​Error Handling

​Best Practices

​Next Steps

Audio/Video Quality

Recording

Overview

Creating a Screen Share Track

Configuration Options

Frame Rate Settings

Resolution Settings

Advanced Settings

Screen Sharing with Audio

Capture System Audio (Chrome 104+)

Audio Quality Settings

Managing Screen Share Tracks

Detect Screen Share

Handle Track Ended

Stop Screen Sharing Programmatically

Content Hint

Platform-Specific Implementation

Chrome/Chromium

Firefox

Safari

Electron

Advanced Use Cases

Replace Camera with Screen Share

Share Camera and Screen Simultaneously

Dynamic Frame Rate Adjustment

Error Handling

Best Practices

Next Steps