Using multiple strategies to control piracy of premium video content has become a necessity for the over-the-top (OTT) platforms, like Netflix and Amazon Prime. Otherwise, OTT players face the dire consequence of losing revenue to illegal hackers. Hollywood studios, which produce premium video content and distribute it all over the world, focus on the importance of content security to contain piracy through digital rights management (DRM) technology. Premium video content owners also want to embed owner, user, and device information in video files at the time of playback in case a piracy attack succeeds.
Hence, OTT content can be protected in two ways: Using the DRM approach and video watermarking technology in tandem, both of which are mostly provided as software as a service by the same vendor, commonly known as multi-DRM SaaS vendors.
As part of forensic watermarking technology, the vendor embeds binary data in the video asset through an SDK. This data contain copyright and user information, which is unique to each user. The vendor’s watermarking algorithm supplements the the DRM technology with imperceptible, but robust, watermarks that a pirate cannot distort easily. Even when a pirate subjects the watermarked video asset to multiple encoding and decoding rounds, the robustness of the data protects it.
Algorithms used for embedding video watermarks in the DRM protected content can vary from category to category. Here are different types of watermarking approaches security experts use to protect video assets Since encrypted video needs to be decrypted before the browser play can play it, the browser requires a content decryption module (CDM). This is crucial in the DRM system without which the targeted video cannot be played. The communication between the browser and the CDM takes place through encrypted media extensions (EMEs), which are APIs in browsers. The OTT content is played through an HTML5 player in web browsers. EMEs allow the use of HTML5 in browsers. A combination of the CDM and an HTML5 browser accommodates the DRM requirements as well as negate the need to download video content through extensions like Adobe Flash and Microsoft Silverlight.
- Post-compression: A forensic watermarking algorithm uses redundant spaces in a compressed video stream. Such spaces can be used to embed forensic watermarks once compression has been completed to the editor’s satisfaction. Separation is the key to this process, as the algorithm and the codec remain as two distinct entities, thus improving efficiency of the watermarked asset.
- Treating the original video: This algorithm enters into the picture before compression is applied on the original video. The algorithm treats the video asset as a series of still images called frames, which create the video effect at a certain frame rate. Watermarking data is embedded to the original frames and then it is compressed and delivered to the CDN.
- Intervening in the encoding process: This approach allows the algorithm to embed watermarks in the video asset during compression. During this process, the program modifies spaces which are not used by the video frame to embed unique information. It protects the code rate of the video asset. This method becomes useful since during decoding watermark extraction can take place in real time.
Watermark extract is important. It has to be a fast process to contain the damage done by piracy. Extraction process depnds on which of the three methods are used to embed watermars.