TL-USBAPI Cross-platform Vendor-specific USB Communication for Windows, macOS and Linux
TL-USBAPI is a host-side, cross-platform, generic library for private USB device communication. It is typically used to access a vendor-specific USB interface that is exposed in parallel to a USB audio class compliant device. Such an interface can implement vendor-specific SETUP requests, data endpoints, or both. A host application can use TL-USBAPI to send private commands to audio device firmware in a platform-independent way.
The library provides a uniform C-style programming interface across all supported operating systems enabling higher software layers to be implemented in a platform-independent way.
The overall software architecture is shown below.
- Windows 11 (64-bit and arm64)
- Windows 10 (32-bit and 64-bit)
- Windows Server 2019 64-bit
- Windows Server 2022 64-bit
- macOS 15 Sequoia (Apple M1 and Intel)
- macOS 14 Sonoma (Apple M1 and Intel)
- macOS 13 Ventura (Apple M1 and Intel)
- macOS 12 Monterey (Apple M1 and Intel)
- Linux (kernel 4.x and later)
TL-USBAPI Key Features
- Supports USB 2.0 full speed and high speed, and USB 3.0/3.1/3.2 super speed or higher
- Enables private firmware commands to be sent in parallel to USB audio class driver operation
- Supports vendor-specific USB interfaces with or without data endpoints
- Supports vendor-specific SETUP requests
- Supports bulk mode IN and OUT data endpoints
- Supports interrupt mode IN and OUT data endpoints
- C-Style, script-friendly, cross-platform programming interface
- SDK with sample code available
- Driverless operation on Windows 10 (if supported by device firmware), no Administrator rights required
- Driverless operation on macOS and Linux
Software Development Kit (SDK)
A software development kit is available for each supported operating system. The SDK enables developers to integrate the TL-USBAPI into their applications. The SDK includes:
- C API declaration (.h file) and reference documentation
- Source code of a command line based sample application
Example Scenarios
- Private communication interface for a USB Audio Class 2.0 or Audio/MIDI 1.0 class compliant device. Such a device can implement a vendor-specific bulk-mode interface in addition to the audio class.
- Vendor-specific bulk-mode USB interface as a replacement for a HID interface that is used for private device communication. See also the comparison below.
- Entirely vendor-specific device implementation (no class drivers) which needs to support multiple operating system platforms.
Comparison with the Widely Used HID Approach
Some advantages over the HID (human interface device class) based approach are:
- Private and hidden device on Windows side. The device is identified by a unique ID (interface GUID) and can be enumerated by dedicated applications only. It is not visible to other applications.
- Full support for vendor-specific SETUP requests with IN or OUT data transfer
- Better throughput. 10..20 MBytes/s per endpoint can be achieved at USB high speed.
- End-to-end flow control in both IN and OUT direction. The Windows HID driver may lose data in IN direction if the application is not consuming data fast enough.
- Less restrictive on transfer message size. Transfer size is variable and can be up to 256 KBytes. Typically it is limited by memory resources on embedded side only.
Software made in Germany
Our software is purely designed and implemented by our team in Germany - no outsourcing. Technical support is provided directly by the developers.
Free Demo, Licensing conditions & Prices
NOTE: The software described on this page is *not for use by end users*. It will not help solve any problems you may experience with a consumer device. Licenses are only available for hardware or software manufacturers.
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