Fixing audio and video desynchronization in Telestream Wirecast requires optimizing your hardware settings, matching your sample rates, and applying precise delay offsets. Lag typically happens when your computer processing slows down or when different devices process signals at different speeds. Check Your Hardware and CPU Usage
High CPU utilization is the primary cause of dropped frames and drifting audio.
Monitor the CPU meter: Keep Wirecast’s internal CPU usage indicator below 70%.
Lower your output settings: Reduce your canvas resolution from 1080p to 720p or lower your streaming bitrate.
Enable GPU acceleration: Go to Preferences > Advanced and ensure hardware acceleration is active for decoding.
Close background applications: Shut down web browsers, resource-heavy apps, and unnecessary background processes. Match Audio Sample Rates
Mismatched sample rates force your system to resample audio on the fly, creating a gradual time drift.
Standardize your system: Set your system microphone, external mixers, and Wirecast to the exact same rate.
Choose 48 kHz: This is the broadcast standard for video and offers the highest compatibility.
Change Windows/Mac settings: Access your OS sound control panel to lock your hardware properties to 48,000 Hz. Apply Manual Audio Delay Offsets
If your video processing takes longer than your audio processing, your audio will arrive too early. Wirecast allows you to delay the audio to match the video.
Identify the source: Double-click the problematic audio or video source in your Shot List to open the Source Properties.
Locate the delay tool: Click on the Audio Properties tab (the speaker icon).
Adjust the clock: Use the Audio Delay slider or type a value in milliseconds.
Calculate the offset: Start with a baseline adjustment of +100ms or +200ms, then fine-tune based on lip-sync testing. Optimize Capture Card Settings
USB capture cards introduce hardware latency that inherently delays video feeds relative to direct audio lines.
Bind audio to video: Whenever possible, feed your audio directly into your camera so the capture card processes them as a single synced stream.
Use USB 3.0 ports: Ensure your capture card connects to a true blue USB 3.0 port rather than a slower USB 2.0 port.
Update device drivers: Install the latest manufacturers’ drivers for your Magewell, Elgato, or Blackmagic devices. Streamline Network Video Sources
Protocols like NDI, RTMP, or IP cameras experience variable network latency that causes random sync drops.
Use wired connections: Disconnect from Wi-Fi and connect all streaming hardware via Cat6 Ethernet cables.
Check NDI settings: Set your NDI sources to “Low Bandwidth” mode if your local network experiences congestion.
To help troubleshoot your specific setup, could you share a few more details? What operating system (Windows or macOS) are you running? Which capture cards or cameras are you using?
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