Frequently Asked Questions

General Questions #

What is FloSync? #

FloSync is a multi-screen content synchronization application for digital signage, video walls, and installations. It displays videos, images, and web pages across multiple screens connected to one computer, or across multiple computers on a network. Video content is kept perfectly synchronized.

What platforms does FloSync support? #

FloSync is available for:

• macOS (11.0 Big Sur and later)
• Windows (10 and later)

What content types does FloSync support? #

FloSync supports three content types:

Videos:

• MP4 (H.264, H.265/HEVC)
• MOV (including Apple ProRes)
• MKV, AVI, WebM

Images:

• PNG, JPG/JPEG
• GIF (including animated)
• BMP, TIFF, WebP
• SVG

Web Pages:

• HTTPS URLs
• Local HTML files (with relative assets)

If you have a video that doesn't work, try converting it to MP4 (H.264) format.

Screen & Hardware Questions #

How many screens can FloSync support? #

FloSync can work with as many screens as your computer supports. Practical limits depend on:

• Your graphics card's output capabilities
• GPU memory and processing power
• Video resolution and bitrate

Most modern systems can handle 2-4 screens. For more screens, consider network sync with multiple computers.

Do I need special hardware? #

No special hardware is required. FloSync works with:

• Any screens connected via HDMI, DisplayPort, USB-C, or other standard connections
• Integrated or dedicated graphics
• Consumer or professional screens

For best results with 4+ screens or 4K+ content, a dedicated graphics card is recommended.

Can I use different resolution screens? #

Yes, FloSync works with mixed-resolution setups. However:

• Mirrored mode: Video displays at each screen's native resolution
• Spanned mode: Works best with identical screens; mixed resolutions may cause alignment issues

How do I create a video wall across multiple computers? #

Use Spanned mode combined with Global Canvas Extension and Network Sync:

1. Set all computers to Spanned mode
2. Configure Global Canvas Extension on each computer to define its position in the wall
3. Use Network Sync (server/client) to keep all computers synchronized
4. Go Live on all computers

For detailed setup instructions, see Network Sync.

Sync Questions #

How accurate is the synchronization? #

FloSync maintains synchronization within your configured tolerance:

• Local sync (same computer): Default 30ms tolerance
• Network sync (multiple computers): Default 50ms tolerance

These tolerances are well below the threshold of human perception (around 45ms), so sync differences are imperceptible in practice.

Why don't screens correct immediately when they drift? #

FloSync waits to confirm drift is persistent before making corrections. This prevents unnecessary adjustments from momentary variations, resulting in smoother playback while still maintaining sync over time.

Can I sync different videos on different screens? #

No, synchronization requires the same video on all screens/computers. For different content, use Independent mode (which doesn't sync).

Does sync work with images and web pages? #

No, synchronization only applies to video content. Images display statically, and web pages render independently on each screen.

Does FloSync sync audio? #

Audio plays from the primary screen. Secondary screens are muted in Mirrored and Spanned modes to prevent echo. Audio timing follows video timing, so synchronized video means synchronized audio.

Network Sync Questions #

How does network sync work? #

One computer runs as "server" and broadcasts its playback position over the network. Other computers connect as "clients" and follow along, automatically adjusting to stay in sync.

After a brief calibration period (a few seconds), all computers stay tightly synchronized. All computers must have the same video file loaded.

What network requirements are there? #

• All computers on the same local network (same subnet)
• UDP port 9201 available
• Low-latency connection (wired recommended)

Can I sync over the internet? #

FloSync is designed for local network use. Internet sync would introduce too much latency for frame-accurate synchronization. For remote locations, consider pre-scheduled playback at specific times.

What if my network is unreliable? #

Increase the network sync tolerance in Preferences (try 100-150ms). This allows more drift before correction, reducing the impact of network variations. Also consider using wired instead of WiFi connections.

What is Global Canvas Extension? #

Global Canvas Extension is a feature for multi-computer video walls. It allows you to define how your local screens fit within a larger "global canvas" spanning multiple computers.

For example, in a 3-computer horizontal wall:

• Left computer: Canvas extends 3840 pixels to the right
• Middle computer: Canvas extends 1920 pixels left and 1920 pixels right
• Right computer: Canvas extends 3840 pixels to the left

Each computer then shows its correct portion of the video.

Mode Questions #

When should I use Independent mode? #

Use Independent mode when:

• Each screen should show different content
• You want separate audio control per screen
• Screens are in different locations and won't be viewed together

When should I use Mirrored mode? #

Use Mirrored mode when:

• All screens should show the same content
• Viewers might see different screens from different positions
• You want simplicity - load once, plays everywhere

When should I use Spanned mode? #

Use Spanned mode when:

• Creating a video wall (multiple screens as one large image)
• Content is designed for a wide/tall format across screens
• Screens are physically adjacent

Can I change modes with a video playing? #

Yes, you can switch modes at any time when not in live mode. The video will adapt to the new mode immediately.

Note: The mode dropdown is disabled during live mode. Exit live mode first to change screen modes.

Go Live Questions #

What is Go Live? #

Go Live is FloSync's fullscreen presentation mode. When you click Go Live, FloSync creates fullscreen windows on each connected screen and plays your videos in perfect sync.

How do I exit live mode? #

There are two ways:

1. Press ESC on any fullscreen window
2. Click "Stop Live" in the control panel

Can I control playback while in live mode? #

Yes, the control panel remains accessible during live mode. Use the timeline and play/pause controls to control playback across all fullscreen windows.

Playback Questions #

Do videos loop automatically? #

Yes, FloSync automatically loops videos - essential for digital signage where content plays continuously.

Can I play a playlist of videos? #

Playlist functionality is planned for a future release. Currently, you load one video at a time.

Does FloSync remember my videos? #

Yes, FloSync automatically saves references to your loaded videos and restores them on the next launch.

Why does my screen show "missing video"? #

This means the video file that was previously loaded has been moved, renamed, or deleted. Load a new video to replace the missing one.

Audio Questions #

Why is there no audio on my secondary screens? #

In Mirrored and Spanned modes, audio only plays from the primary screen to prevent echo. This is intentional. Only Independent mode allows separate audio per screen.

How do I enable audio on a screen? #

Click the speaker icon on the screen box. In Independent mode, each screen has its own audio toggle. In Mirrored/Spanned modes, the toggle controls the primary screen's audio.

Feature Questions #

Can FloSync play images? #

Yes! FloSync supports images including:

• PNG, JPG/JPEG, BMP, TIFF, WebP
• Animated GIFs (they loop automatically)
• SVG vector graphics

Can FloSync display web pages? #

Yes! FloSync can display:

• HTTPS URLs - Right-click a screen and select "Load Web Page URL"
• Local HTML files - Right-click and select "Load HTML File"

Web pages can be configured to auto-refresh at intervals (15min, 30min, or 1hr).

Note: Only HTTPS URLs are supported. Web pages cannot be spanned across screens.

Does FloSync support scheduling? #

Yes! FloSync has two scheduling modes:

Time-of-Day Mode:

• Divide the day into time scenes with different content
• Configure unique schedules for specific days of the week
• Use "Go Live (Schedule)" to play scheduled content automatically

Interval Mode:

• Duration-based content cycling (5m, 10m, 30m, etc.)
• Cue scenes that wait for keyboard input before advancing
• Keyboard controls during live: arrow keys, number keys 1-0
• Use "Go Live (Beginning)" to start from scene 1

Both modes support smooth fade-to-black transitions between scenes.

Click the schedule icon (agenda/list) in the toolbar to access the schedule panel. Use the calendar and timer icons to switch between modes.

Does FloSync support vertical/portrait screens? #

Yes, FloSync works with any screen orientation. Configure your screen rotation in your operating system settings, and FloSync will follow.

Troubleshooting Questions #

Which video codec works best for sync? #

For best sync performance, use H.264 All-Intra encoding. See the Video Preparation guide for recommended formats, sample files to test, and transcoding instructions.

How do I save my configuration to use on another computer? #

Use File > Export Configuration (⌘S on macOS, Ctrl+S on Windows) to save your complete setup to a .flo file. This includes your schedule, content assignments, display mode, and canvas extension settings.

On the other computer, use File > Import Configuration (⌘O on macOS, Ctrl+O on Windows) to load the file. If content files are in different locations, FloSync will help you locate them.

How do I reset FloSync to start fresh? #

Use File > Reset Everything from the menu bar. A confirmation dialog will appear showing what will be cleared:

• All schedule scenes (reverts to a single "All Day" scene)
• Content assignments for each display
• Global canvas extension settings

Your preferences (sync tolerances, etc.) are preserved.

How do I completely reset FloSync including preferences? #

1. Close FloSync
2. Delete the preferences folder:
   • macOS: ~/Library/Application Support/com.tentekio.flosync/
   • Windows: %APPDATA%\Tentekio\FloSync\
3. Relaunch FloSync

Why does FloSync need firewall permissions? #

Network sync uses UDP broadcast to discover servers and sync playback. Without firewall permissions, network features won't work. Local multi-screen sync doesn't require network access.

What video player backend should I use? #

FloSync offers two video backends:

• FFmpeg (Default) - Supports more formats including ProRes and DNxHR, and provides consistent seeking behavior. This is the recommended choice for most users.
• Native - Uses the operating system's video player (AVFoundation on macOS, Media Foundation on Windows). Try this if you experience issues with specific H.264/HEVC files.

You can change this in Preferences under "Video Playback". A restart is required after changing.

Where can I find FloSync's logs? #

Go to Help > Open Log Folder to access diagnostic logs. Logs are organized by date (folders) and hour (files), and are kept for 7 days. These are helpful when troubleshooting issues or contacting support.

See Troubleshooting - Diagnostic Logs for more details.

What is Controller mode? #

Controller mode is a special Go Live option available when running as a server. It lets you broadcast to network clients without creating fullscreen windows on your local machine - useful when operating a video wall from a control booth.

See Scheduling - Controller Mode for details.

MIDI Controller Questions #

Does FloSync support MIDI controllers? #

Yes! FloSync supports MIDI controllers for triggering interval scenes during live performances. You can map any pad or button on your MIDI controller to switch between scenes instantly.

What MIDI controllers work with FloSync? #

FloSync works with any MIDI controller that sends Note On, Control Change, or Program Change messages. This includes:

• Novation Launchpad (all models)
• Akai APC (APC40, APC Mini, and MK2 versions)
• Arturia Minilab 3
• Native Instruments Maschine
• Any other MIDI controller with pads or buttons

How do I set up MIDI control? #

1. Open Preferences and enable MIDI Controller
2. Select your MIDI device from the dropdown
3. In the Schedule Panel, switch to Interval Mode
4. Click the Learn button on a scene, then press a pad on your controller
5. The mapping is saved automatically

See Preferences - MIDI Settings for detailed instructions.

Do the LEDs on my controller light up? #

Yes, if your controller has LED-equipped pads, FloSync sends color feedback:

• The active scene's pad lights up brightly
• Other mapped scenes show at lower brightness
• You can customize colors per-scene using the palette icon

LED support varies by controller. Newer controllers like Launchpad X and APC Mini MK2 have full color support, while older models may have limited colors.

Does MIDI work with network sync? #

Yes. When using server/client mode, MIDI triggers on the server automatically broadcast to all connected clients. This means you can control a multi-computer video wall from a single MIDI controller.

Note: Clients do not process local MIDI input during live mode - only the server responds to MIDI.

My MIDI controller isn't showing up #

Try these steps:

1. Click the refresh button in the MIDI device dropdown
2. Make sure no other application is using the MIDI device exclusively
3. On Windows, ensure the MIDI drivers are installed
4. Try disconnecting and reconnecting the controller

Getting More Help #

If your question isn't answered here:

1. Check the Troubleshooting Guide
2. Review other documentation sections
3. Contact support

Have a question that should be in this FAQ? Let us know!