OBS Capture Card Setup and Compatibility: Video, HDMI Audio and Speech Capture

The short answer

Most USB capture cards work in OBS Studio with no special plugin. You add them as a Video Capture Device source, and USB cards that follow the standard video and audio device classes (often described as UVC and UAC, or "driverless") typically appear on Windows, macOS and Linux without extra software. Internal PCIe cards and some USB models depend on vendor drivers, so whether they work on your operating system, and on Apple Silicon Macs in particular, comes down to the manufacturer's current driver support rather than OBS itself.

For speech, a capture card only carries whatever audio arrives over HDMI. With a DSLR or mirrorless camera, that is usually the camera's built-in microphone, which tends to sit far from your mouth. A dedicated microphone, connected either to the computer or to the camera's mic input, is the more dependable route to clear voice. Also note that OBS's built-in virtual camera sends video only, so a conferencing app still needs its audio from a separate source.

The material supplied for this guide contained no model-specific specifications, latency figures, prices or test results. Everything below is based on general OBS behaviour and common capture practice. Check your card's and camera's documentation for exact supported formats and driver requirements.

What decides whether a capture card is compatible with OBS

Factor | Why it matters | What to check

Driver model | Class-compliant USB cards use the operating system's built-in drivers. Others need vendor software. | Whether the vendor lists your OS version and processor type

Connection type | Bandwidth affects which video formats the card can deliver. Lower-bandwidth links often rely on compressed formats such as MJPEG. | That the card is on a port matching its rated USB generation, or the correct PCIe slot

Input signal | The card must accept the resolution and frame rate the camera sends over HDMI. | That the camera's HDMI output settings fall within the card's supported input list

Audio path | HDMI audio may show up as part of the video device or as a separate audio input. | Whether the card exposes a separate audio device on your OS

Exclusive access | Some apps hold a capture device open so others cannot use it at the same time. | Close other camera or vendor preview apps before opening OBS

Preparing a DSLR or mirrorless camera for HDMI capture

• Enable clean HDMI output so focus points, battery icons and other overlays are not sent to the capture card. Many cameras call this an HDMI info display setting.
• Set the camera's HDMI output resolution and frame rate to something the capture card accepts, and plan to match it in OBS.
• Turn off auto power-off or sleep timers, which can cut the signal partway through a call or recording.
• Use continuous power, such as a dummy battery or AC adapter, if your camera supports it. Long sessions can drain a battery.
• Check whether your camera sends audio over HDMI at all. Some do and some don't, and the documentation for your model is the place to confirm.

Adding the capture card in OBS Studio

• In the Sources panel, add a Video Capture Device and select the capture card by name.
• Set Resolution/FPS Type to Custom, then choose the resolution and frame rate that match the camera's HDMI output.
• If the card offers more than one video format, such as YUY2, NV12 or MJPEG, choose an uncompressed format when the connection supports it at your chosen resolution. Use a compressed format when it doesn't.
• If the preview is black, close any other app that might be using the card, then deactivate and reactivate the source. Confirm the camera is actually outputting over HDMI and is not in playback or menu mode.

Getting the capture card's audio into OBS

How HDMI audio appears depends on the operating system. On Windows, the Video Capture Device properties include an option to use a custom audio device, where you select the card's audio input. There is also an Audio Output Mode setting. Choosing "Capture audio only" keeps the audio inside OBS's mixer. The desktop audio output modes also play it through your speakers, which can cause echo on a call. On macOS and Linux, the card's audio commonly appears as its own input, which you add through an Audio Input Capture source.

If you see no meter movement in the Audio Mixer, the cause is often one of two things. The camera may not be sending audio over HDMI, or the card's audio device may not have been selected. Check both before suspecting a compatibility problem.

Choosing a speech source: camera audio versus a dedicated microphone

Option | Typical strengths | Typical drawbacks

Camera's built-in mic over HDMI | No extra hardware, and audio travels with the video | Usually mounted far from the speaker, so it picks up more room sound and lens or handling noise

External mic into the camera's mic input, carried over HDMI | Mic can be placed close to the speaker, and audio stays tied to the video path | Depends on the camera's preamp and level controls, which vary by model

USB or interface-connected mic into the computer | Independent of the capture chain, easy to select in OBS or a conferencing app | Arrives at a different time from the video, so it may need a sync offset

The general rule of microphone placement applies here: the closer the mic is to the speaker's mouth, the more voice it captures relative to room noise and reverberation. That is why a camera-body mic aimed at a subject across a desk usually sounds more distant than a mic placed nearby. No measured comparison of specific setups was available for this guide.

Keeping voice and video in sync

Capture cards add processing delay to video, and the amount varies by card, camera and settings. A microphone connected directly to the computer can therefore be heard slightly before the lips move. OBS can compensate with a sync offset, set per source under Advanced Audio Properties, which delays the microphone to match the video. Find the right value by testing. A simple method is to record a sharp clap on camera, play the recording back, and adjust the offset until the sound and the image line up. Audio that travels over HDMI with the video usually needs little or no offset, though this also varies by device.

Using the capture card in conferencing apps

There are two common routes. You can select the capture card directly as a camera in the conferencing app, if the app recognises it and OBS isn't holding it open. Or you can keep the card in OBS and start OBS's virtual camera, which lets you add overlays or framing before the picture reaches the call.

The virtual camera carries no sound, so audio has to be set separately in the conferencing app. The simplest option is to choose your microphone directly as the app's input. If you want the call to receive audio processed in OBS, such as filtered or offset audio, you need a virtual audio device that routes OBS's output into the app as a microphone. That requires additional software, and behaviour depends on the tool and operating system. When you choose the microphone directly in the conferencing app, any sync offset set in OBS does not apply, so check lip sync on a test call.

What this guide could not confirm

• Which specific capture card models are class-compliant or need drivers on a given operating system.
• Latency values for particular cards or cameras, and therefore exact sync offsets.
• Which camera models send audio over HDMI, and how their mic inputs perform for speech.
• Speech quality comparisons between camera mics and dedicated microphones in measured tests.
• For each of these, check the manufacturer's current documentation or carry out your own short test recording.