Back when the first version of the Video 4 Linux (V4L) API was written, video acquisition and output devices available to Linux users ands developers only offered basic functions. With the introduction of hardware compression, V4L showed its limits and the new V4L2 API saw the light of the day in the 2.5.x kernels. Video hardware available today once again pushes the Linux video API to its limits, and there's no doubt that tomorrow's devices will offer even more complex features.