October 8, 2013 – Forensic watermarking of high-value VOD content on a per-session basis is suddenly moving to the front burner, thanks to the motion picture studios’ desire to create greater security for content delivered in 4K Ultra-High HD format.
“We’ve seen the new requirements for digital watermarking that will soon be published by MovieLabs for 4K content,” says Steve Oetegenn, chief sales and marketing officer at content protection supplier Verimatrix, in reference to the just-released recommendations from the Motion Picture Laboratories, Inc, technology consortium set up by six major studios in the mid-2000s. “Watermarking is being mandated for recent releases of movies delivered to consumers in 4K.”
The emergence of 4K with a higher level of security also brings back into play the possibility the studios may pursue an early-release strategy analogous to the failed attempt to offer a high-priced home theater service in 2011. Push back from theater chains and lackluster market response to the initial offerings through DirecTV’s long-abandoned $30 per-movie Home Premiere service ended efforts to release first-run movies into VOD distribution within 60 days of theatrical release.
But the potential appeal of such high-priced showings to 4K households with new big-screen TVs and relatively little 4K content to view introduces a different market dynamic that could well reignite the early-release strategy. At the same time, as Oetegenn notes, the watermarking requirements on all new movies released into traditional VOD for 4K distribution represent a challenge for pay TV providers who want to compete with OTT offerings of older 4K movies and original programming to be offered by Netflix next year.
“We’re a ways away from seeing 4K go in the VOD space, because of security concerns,” he says. “That’s one reason 4K is likely to show up sooner in OTT services offering older content.”
While CE and set-top manufacturers have gone to great lengths to prevent transfers of encrypted content from the network to the display in the clear, it’s still possible to hack those crossover points in some cases. Of greater concern is the combination of high-resolution displays, especially with the onset of 4K, and high-res cameras, which allow thieves to record a digital copy of the content with almost no loss in quality.
Knowing where such theft occurs is critical to allowing distribution of early release content, especially 4K. In the event of theft, the stolen copy is examined to determine whose watermark was used and then sent to that supplier for discovery as to the point of origin. The fact that there are multiple modes of watermarking available from a handful of suppliers complicates the process, but the industry, despite not having a standard approach, has been taking steps to streamline the forensic processing.
To inject the invisible digital watermarking codes with each VOD session in order to identify potential sources of theft requires either a watermarking capability at the set-top or other receiving device or a means of doing so on the fly with each individual stream. As previously reported, Verimatrix has introduced a means, known as “StreamMark,” to enable per-session watermarking of encrypted content as it is streamed from VOD servers and CDN cache points with a level of invisibility and robustness sufficient to studio standards.
While the stall on early-release for VOD in the U.S. slowed demand for StreamMark, the technology “is ready to go,” Oetegenn says. In fact, he adds, there are instances where watermarking has been mandated for early releases of movies into the hospitality markets in Thailand and Pakistan. “All of these have watermarking from us,” he says.
Now a second approach to injecting watermarks for VOD viewing without requiring that the codes be applied at the set-top has been introduced by Civolution, another leader in the field, in conjunction with the edge-processing technology supplied by SeaWell Networks. As described by Brian Stevenson, vice president of product management at SeaWell, the joint solution combines the edge-based, per-session encryption capability of SeaWell’s Spectrum Session Delivery Controller with Civolution’s NexGuard forensic watermarking technology in a unique way that minimizes the level of processing required for per-session watermarking.
Rather than inserting watermarks on the fly, the method entails having two files available in storage for each video that requires watermarking, one that hasn’t been watermarked and one that has. When a user requests access to the video both files are streamed to the edge-based Session Controller, where they are stitched together on a frame-by-frame basis in such a way that each stream going out from the edge to the end user is uniquely watermarked. “We’re handling this at the physical and manifest levels without actually injecting watermarks into each stream,” Stevenson says.
The trigger to the process at the controller comes from a key delivered from Civolution, he adds. “All the watermarking is based on algorithms used with their SDK (software development kit),” he says.
As with any watermarking technique, the joint solution identifies each streaming session and creates an imperceptible, uniquely watermarked video stream at the network edge without impacting the viewer’s experience, he says. Each stream is then repackaged for any adaptive bit rate (ABR) format, encrypted and protected with DRM for per-session distribution.
As another software-defined option on top of the per-session DRM protection, quality-of-experience, packaging, ad targeting and other capabilities provided by SeaWell’s Spectrum, the technique does not add costs to the existing infrastructure, Stevenson notes, adding that the company has not yet decided how or whether to monetize the option. “We do see that distributors can negotiate better rights to content if they can support watermarking along with the per-session DRM enabled on our platform,” he says. “The watermarking capabilities provide another compelling reason to use our platform.
“With Spectrum in place you can determine which pieces of content you want to protect with watermarking, which gives you flexibility in terms of what you offer and the release windows with those offering,” he adds. “It’s a lot simpler than trying to watermark at the set-top or on each session from the server. One of our MSO customers is very interested in pursuing this approach.”
Oetegenn says that while he doesn’t see how this approach would be any cheaper or simpler than the Verimatrix StreamMark approach, he welcomes news that other suppliers are offering per-session streaming solutions for watermarking. “Any proof of the idea of watermarking is great,” he says.
In the case of StreamMark, which uses Verimatrix’ studio-approved VideoMark watermarking technology, there are three steps entailed, including pre-processing, embedding and extraction. Pre-processing, which takes place when content is ingested, consists of an automated analysis of the video file to determine which frames are the best candidates for marking. The system then creates a set of replacement data consisting of marked frames which will be inserted during the embedding process.
The embedding process occurs when the streaming server picks up the content from storage and starts streaming it to a specific end user. At that point the StreamMark system inserts the replacement frames into the stream, marking the content with invisible numbers identifying an account or transaction number that can be traced back to that user. Not every replacement frame created in the pre-processing step is actually inserted in the stream, which allows the system to choose a sequence for placement that is unique to each user, thereby eliminating any predictability that might be used by thieves to identify where the watermarks are.
While StreamMark can be used on standalone servers to handle a limited volume of streamed files, it needs to be integrated with existing VOD servers to handle high volumes of content, which requires integration with different types of encoding systems and VOD platforms. Verimatrix was engaged with various pay TV providers in this process when the early-release window strategy was underway two years ago. Now, it appears, such efforts will soon resume.