Logitech C922 Pro Stream A/V Sync & Latency Test

Logitech C922 Pro Stream A/V Sync Test: Measure Audio Offset for Twitch

For C922 Pro Stream sync work, the capture mode matters as much as the camera model. C922 Pro Stream is a streaming webcam rated for 1080p/30fps and 720p/60fps, with a 78° diagonal field of view and USB 2.0 connection.¹ Logitech's support specs list UVC 1.1 support, a tripod mounting option, and 720p/60fps as the camera's maximum high-frame-rate mode.

The key variable for streamers is which resolution the camera runs during production. At 720p/60fps the camera delivers frames twice as often as at 1080p/30fps, reducing the inter-frame window between the clap motion and the first frame that captures the peak luminance. Test in the same resolution your OBS scene uses, because the browser-delivered track settings and camera mode affect the measured offset.

Specifications²

Connection and browser setup

Connect the C922 Pro Stream directly to a USB-A port on your computer. Sharing a USB hub with another high-bandwidth device can increase contention on the same USB topology, which can widen the spread between readings. Grant camera and microphone access in Chrome or Edge; the Media Capture and Streams API requests local media tracks from the browser and exposes the final width, height, and frameRate settings on the delivered tracks.³ The C922 can run through Windows' system UVC driver, so basic camera access does not require a Logitech-specific driver.⁴

For 720p/60fps testing, keep the camera mode and browser-delivered track settings the same when you compare readings. This tool measures the stream that the browser actually delivers, so test in the same resolution and frame rate your OBS scene captures. The C922's MJPEG compression at 720p/60fps uses more USB bandwidth than 1080p/30fps, which means the camera is more sensitive to USB controller contention at the higher frame rate; a port that delivers clean 1080p/30fps readings may show wider spread at 720p/60fps if other devices share the same controller.

Choosing the right USB port for stable C922 readings

For the most stable five-reading cluster, connect the C922 directly to a USB-A port on your computer instead of a shared hub with other active USB devices. Microsoft documents USB bandwidth as a shared resource across the host controller and device tree, with hubs and other clients consuming part of the available bandwidth.⁵ On laptops, moving between ports may not change the underlying internal hub, so focus on keeping the topology and competing devices consistent while measuring.

Common A/V sync issues with this model

MJPEG is a UVC compressed video format, and the C922's 720p/60fps mode uses more bandwidth than lower-frame-rate modes.⁴ If multiple USB video devices are active on the same host controller, they compete for the same USB bandwidth pool. Moving the C922 to a port that maps to a different controller can reduce contention-related variance, but the important test is to keep the same USB topology while measuring.⁵

Frame-rate matching is the other common sync issue. OBS exposes Resolution/FPS Type and FPS settings for video capture devices, and the source will not display if the selected frame rate is unsupported by the device.⁶ Set OBS capture to the same camera mode you test here, then use the five-clap result for that mode. A mismatch between the browser test frame rate and the OBS capture frame rate is one of the most common reasons a measured correction fails to fix the problem in the final recording, so double-check both settings before entering the value.

Matching OBS mode to your test result

Match the OBS capture mode to the browser-delivered track settings before you trust a sync offset. If the C922 delivers 720p/60fps in the browser but OBS records 1080p/30fps, the camera may use a different internal path and the measured correction can shift. Keep the mode fixed, measure, enter the offset, then verify with a short recording.

Long recordings can still drift if audio and video clocks run at slightly different rates, but that is a separate issue from the static offset this tool measures. The clap test gives you the initial correction for the current browser stream; matching your capture settings keeps that correction relevant across your recordings. Sample rate mismatch is the usual culprit behind progressive drift, so set all audio devices to the same rate, typically 48 kHz, before relying on a static correction for sessions longer than 30 minutes.

What the test covers

The clap test measures the browser-level offset: the time gap between a luminance transient in the video stream and an amplitude transient in the audio stream, both sampled against the same browser clock. At 1080p/30fps on the C922, this offset reflects the camera mode, browser stream settings, and USB scheduling added to the video path.

OBS source timing is based on audio and video timestamps, so the sync value you enter should match the measured browser stream conditions as closely as possible.⁷ Enter the value in OBS under Edit > Advanced Audio Properties > Sync Offset (ms) for your microphone source, then record a short test clip to verify the clap sound aligns with the visible hand impact.⁸

Multi-camera OBS scenes

When you use the C922 as one of several cameras in a multi-camera OBS scene, measure the C922-to-microphone offset separately from any other webcam-to-microphone offsets in your rig. Each camera has its own pipeline latency, and the Sync Offset field applies to the selected audio source for the active scene. Isolating the C922's offset in a multi-cam rig means re-measuring after any USB configuration change, driver update, or change in OBS capture resolution to keep the correction current.