USB Audio & Video 04: USB Can Carry Almost Anything—But There’s a Catch

One Cable, Three Decades

The first USB specification was released in 1996.

That year, Steve Jobs hadn’t returned to Apple yet. The internet was just beginning to escape the labs. Windows 95 was still fresh. The back of an average PC was studded with “dedicated ports”—serial port for the mouse, parallel port for the printer, PS/2 for the keyboard, SCSI for hard drives, joysticks had their own 15-pin D-sub connector, sound cards had circular input/output jacks. Every peripheral type had its own port, its own cable, its own voltage standard, its own driver.

PC users of that era share a common memory—connecting a peripheral was something that required “engineering.”

USB was born to solve exactly this. Its goal was modest yet wildly ambitious: one port, one cable, connecting all peripherals.

Thirty years later, USB not only achieved this—it has exceeded its original imagination by orders of magnitude. The devices that connect to computers via USB today include:

• Storage—flash drives, external hard drives, SD card readers, external SSDs
• Input devices—keyboards, mice, touchpads, drawing tablets, gamepads, VR controllers
• Audio/video—webcams, microphones, headsets, audio interfaces, displays, capture cards
• Networking—USB Ethernet adapters, USB Wi-Fi, 4G/5G modems, Bluetooth dongles
• Printing and output—printers, scanners, 3D printers, label makers
• Professional instruments—oscilloscopes, signal generators, medical devices, lidar, industrial controllers
• Even graphics cards—USB4 / Thunderbolt supports external GPUs (eGPUs)
• Even other computers—USB debugging bridges, embedded development board flashing ports

The list goes on. Walk into any electronics shop, almost every digital peripheral connects via USB.

This is a colossal triumph of engineering civilization.

But behind this achievement lies a premise—one we’ve been relying on across the previous three articles, but never named directly—

USB Can Carry Anything—But the Computer Has to “Understand” What Arrives

What USB does at the physical and protocol layers is essentially “move arbitrary digital data from end A to end B.” It doesn’t care what the data means. Is this video? Audio? A file? A control command? USB protocol doesn’t care. It just carries bytes accurately, in order, on time.

But once the computer receives those bytes, something has to be done with them—the computer has to know what the bytes represent.

Video streams need to be decoded as video and displayed on screen. Audio streams need to be decoded as audio and played. File data needs to be stored on disk according to a filesystem structure. Keystrokes need to be mapped to specific characters and delivered to the active application. Print jobs need to be translated, via the printer’s protocol, into ink dots on paper.

This capability of “interpreting data in a specific way” is, in essence, what a driver does.

A driver is, fundamentally, a piece of code that tells the OS “this is how to use this device.” It knows the device’s data format, command set, and state feedback mechanism. Without an appropriate driver, no matter how wide, how fast, how stable the USB pipe is, the computer is staring at a stream of uninterpretable bytes.

So strictly speaking—

USB solves “how data is transmitted.”

Drivers solve “how data is used.”

The USB protocol alone cannot make a device “automatically usable.” For a USB device to truly work on a computer, USB protocol + driver, both are required.

Two Approaches: Vendor-Written Drivers, or Standardized Drivers?

Here the path forks into two.

Path one: device manufacturers write their own drivers. Manufacturers know their own devices best—the data format, command set, special features. Letting the vendor write the driver is the technically most direct path. Printers, professional sound cards, drawing tablets, lidar, medical instruments—these devices all take this path. They ship with an installation disc, or you download a driver installer from the vendor’s site.

Path two: define a unified device class standard, have all similar devices conform to it, and have the OS implement a single generic driver. All conforming devices work automatically. This is exactly what the past three articles covered—UVC, UAC, plus HID (Human Interface Device) for keyboards and mice, MSC (Mass Storage Class) for flash drives and external drives, and so on.

Which path is better?

It depends on the use case.

For devices with highly differentiated functionality and strong vendor-specific features—like professional MIDI controllers, high-end printers, specialized medical instruments—path one is reasonable. These devices have such specialized functions that the cost of standardization exceeds the benefit.

For devices with highly universal requirements, enormous user bases, and cross-platform adoption—like keyboards, mice, flash drives, webcams, microphones—path two is the absolute winning strategy. Once the standard is established, the entire industry and every user benefits.

This is why keyboards/mice are HID, flash drives are MSC, webcams are UVC, microphones are UAC—they’re all peripherals that “every user uses daily, across every device and platform.” They had to go the standardization route.

Printers, professional drawing tablets, and specialized peripherals still use vendor drivers—nothing wrong with that. It’s just that their requirements aren’t “universal.”

But—the Driver Path Is Increasingly Impassable in Modern IT

From a pure technology standpoint, “vendor drivers” and “standardized drivers” are two engineering choices, each appropriate to different scenarios.

But today we have to discuss something more important than the technical choice—

Modern IT management’s attitude toward “installing drivers” has fundamentally changed.

Twenty years ago, installing a new driver was routine—you bought a device, opened the disc, ran setup.exe, rebooted, done.

But in today’s enterprise IT environment, “installing unapproved software” is essentially a forbidden act.

The reasons aren’t hard to understand—

First, security risk. Drivers run in OS kernel mode with extremely high system privileges. A vulnerable driver can be exploited by attackers to gain control of the entire system. History is full of real cases: printer driver from vendor X found to contain a remote code execution vulnerability; webcam driver from brand Y used as a malware injection vector; USB-C dock driver from brand Z discovered to include unauthorized data collection modules…

Second, stability risk. Low-quality drivers cause blue screens, system crashes, weird compatibility issues. When a company laptop crashes because of an odd driver, the IT team often spends hours just figuring out the cause.

Third, compliance requirements. In finance, healthcare, government, and defense industries, what software is allowed on computers is strictly regulated. An unvetted driver entering the system can directly violate industry compliance.

Fourth, management overhead. A company with thousands of laptops, if each one needs a vendor driver manually installed, the IT operations cost explodes. Unified OS images, unified policies, unified deployment packages are the basic requirements.

So the IT policy of mainstream enterprises today is essentially the same single sentence—

Devices that require “installing a special driver to work” are, in principle, not allowed to connect to company computers.

This isn’t a technical issue. This is a management issue, a security issue, a compliance issue. Even if a device is technically excellent, functionally rich, and high-quality, if it requires a special driver to operate, it’s essentially “undocumented immigrant” status in a compliant enterprise IT environment.

UVC / UAC: The Only Truly “Compliant” Solution for the Modern IT Era

Once you grasp this, you can see UVC and UAC’s value in a new light—

They’re not merely “convenient.”

They are the only management-compliant way for audio/video peripherals to enter computers in this era.

A UVC camera plugged into a company laptop:

• No driver needed → doesn’t violate IT security policy
• Natively supported by OS → introduces no third-party code into the system
• Standard interface → no compatibility surprises
• Cross-platform consistency → works on unified OS images
• Clean disconnection → leaves no residual artifacts

The same applies to UAC audio devices.

Meanwhile, a video capture solution that requires a special driver—no matter how technically excellent, how high its image quality, how rich its features—is essentially “illegal immigrant” status in a tightly managed enterprise environment. It can’t pass IT approval, can’t enter the deployment manifest, can’t be installed on employee computers.

This is why “driverless plug-and-play” is no longer a “convenience feature” today—it’s an entry ticket to the enterprise market.

The NDI Tools virtual camera. The OBS virtual camera. Various third-party bridging software—they technically work. But in tightly managed enterprise IT environments, they’re often “not allowed.” Either the IT team blocks them outright, or there’s a lengthy approval process, or the employee simply doesn’t have admin rights to install them.

We often see this scenario—

The meeting room is equipped with all the professional NDI cameras. But the conferencing laptop runs a corporate-managed standard image, which doesn’t allow installation of any “special software.” The professional picture can’t get into the laptop. The meeting proceeds with the laptop’s built-in webcam.

Tens of thousands of dollars of equipment investment, instantly nullified by the compliance wall.

This isn’t a technical problem. It’s a rules problem.

A Standard Chosen by the Times

Stepping back, we can finally understand UVC and UAC for what they are—

When they were born in 2003 (UVC 1.0) and 1998 (UAC 1.0), they were not designed to solve “enterprise compliance.” That concept barely existed at the time. They were created to solve something simple: stop making USB cameras and microphones require driver installations every single time.

But twenty-plus years later, the times changed.

Enterprise IT management matured. Security and compliance requirements tightened. Unified image deployment became standard practice. “Installing a driver”—a small thing twenty years ago—became an almost insurmountable compliance wall.

And UVC / UAC—two old standards designed back then to be “driverless”—happened, by remarkable luck, to perfectly fit the demands of today.

They weren’t invented by their times. They were chosen by them.

All the technical details across the previous three articles—UVC’s negotiation protocol, MJPEG’s format choice, USB Isochronous transfer mode, DP Alt Mode’s lane-borrowing—every engineering decision converges, today, on a single outcome:

Letting professional audio/video equipment connect to computers in a way that’s driverless, plug-and-play, OS-natively-supported, and enterprise-IT-compliant.

This is the most precious legacy of USB’s thirty-year standardization war.

---

We’ve now covered the full picture of USB audio/video technology—

Part 1 covered the history of UVC / UAC standards. Part 2 covered how audio/video is captured into computers. Part 3 covered how audio/video is output from computers. Part 4, just now, covered the deep relationship between USB standardization and modern IT compliance.

But there’s one specific question we haven’t answered yet—

The professional, high-image-quality devices—broadcast-grade PTZ cameras, NDI cameras, 4K live-production cameras—they were never USB cameras to begin with. They use SDI, NDI, HDMI, IP networks.

By logic, they should be incompatible with “driverless plug-and-play.” Traditionally, getting their pictures into a computer means only one path: install specialized software in the computer that “translates” these signals into a virtual camera.

And that path, as we just established, is exactly the one that doesn’t work in modern enterprise IT.

So—is there a way to make a professional IP camera disguise itself as a standard UVC webcam, so the computer natively recognizes it, with no driver, no software, instantly?

This is harder than it sounds. It requires deep understanding of UVC protocol, hardware-level implementation of the complete Probe-Commit mechanism, professional-grade video stream conversion within reasonable latency, and correct format choices within USB bandwidth constraints.

But if you can pull it off, the value is enormous—it lets “professional image quality” and “enterprise IT compliance” coexist for the first time.

That’s the story of the next and final part—

When a professional camera pretends to be a USB webcam.

See you next time.

---

USB Audio & Video: The Untold Story · Kiloview