US 6,014,694 · Granted 2000-01-11

How Citrix Cracked Adaptive Video Streaming Before YouTube Existed

Imagine trying to watch a video on your phone, but your internet speed keeps changing as you move around. This patent solves that problem by automatically adjusting video quality in real time, dropping resolution or frame rate to keep the stream smooth no matter if you're on slow dial-up or fast WiFi.

Curated and verified by the IsItPatented Editorial team

The plain-English version

What it protects

The claim covers a video compression and transmission system that automatically adjusts video quality based on available network bandwidth. Specifically, it protects the method of dynamically changing compression ratios, frame rates, and image resolution on the fly, as well as the technique of encoding video into Key, P, and B frames with multiple quality levels so that different bandwidth conditions (from 20 Kbps dial-up to multi-megabit LAN) can be accommodated without stopping playback or requiring manual intervention.

Why it matters

This patent represents an early solution to a fundamental problem that would dominate internet video for decades: how do you stream smoothly when network conditions are unpredictable? Citrix filed this in 1997, years before YouTube, Netflix, or modern adaptive streaming standards existed. The core insight—dynamically adjusting quality rather than buffering endlessly or failing outright—became the foundation for how streaming video works today, even though later patents and standards (like DASH and HLS) would eventually take over the market.

Real-world use

When you watch a video on your phone and it automatically switches from HD to a lower resolution as you move into a weak WiFi zone, you're experiencing the same adaptive principle this patent describes.

Original USPTO abstract

A system for adaptively transporting video over networks wherein the available bandwidth varies with time. The system comprises a video/audio codec that functions to compress, code, decode and decompress video streams that are transmitted over networks having available bandwidths that vary with time and location. Depending on the channel bandwidth, the system adjusts the compression ratio to accommodate a plurality of bandwidths ranging from 20 Kbps for POTS to several Mbps for switched LAN and ATM environments. Bandwidth adjustability is provided by offering a trade off between video resolution, frame rate and individual frame quality. The system generates a video data stream comprised of Key, P and B frames from a raw source of video. Each frame type is further comprised of multiple levels of data representing varying degrees of quality. In addition, several video server platforms can be utilized in tandem to transmit video/audio information with each video server platform transmitting information for a single compression/resolution level.

Patent details

Publication number: US 6,014,694
Filing date: 1997-06-26
Grant date: 2000-01-11
Assignee: Citrix Systems, Inc.
Inventor(s): AHARONI; AMIR, KHIRMAN; STAS, TAITS; EUGENE, ARIEL; OREN
CPC class: H04N21/234381

View original record on Google Patents →

Want to file your own patent?

If you're building streaming video tech or a consumer electronics app, check our free patent scanner to see what's already locked down in adaptive video and how to design around it.

Free patentability scan