Video watermarking adds visible text to live, playback, and exported video processed by Security Center. This text includes identifying information that is intended to deter unauthorized users from leaking video recordings.
Watermarking is configured for specific users or user groups. When enabled, video requested by affected users through Config Tool, Security Desk, and Web Client includes identifying text.
Video watermarks are printed as an overlay onto live and playback video. These static overlays are not redrawn when performing a digital zoom or dewarping.
- Security Center user who requested the video
- Workstation where the user logged in
- Camera where the video originated
Each selected variable is displayed on a separate line forming the watermark.
The position, size, and opacity of watermark text can be configured as needed. Watermarks can also be displayed as a mosaic, which duplicates the text to cover the video.
Only users with watermarking enabled see this text. If another user with watermarking disabled views the same live or playback video, it does not include identifying information. This allows authorized users to display and release unobstructed video.
Watermarks and exported video
Watermarks in exported files are visible to all users. To permanently incorporate the text overlay into the video stream, watermarked recordings are transcoded to H.264 during the export process. This transformation is supported to a maximum resolution of 1080p, and can affect video quality.
- Watermark text that is exported with a warped video stream is distorted after dewarping.
- Some dewarping software requires unadulterated input. Applying a watermark during export can interfere with future dewarping.
To permit transcoding, users need the Convert exported files privilege, which allows them to export watermarked video. The following table summarizes when an exported video file is transcoded:
|File format||Input watermarked?||Output transcoded?|
|G64x and G64||No||No|
Video watermarking introduces transcoding to the export process for G64x, G64, and MP4 files. Exporting video in these file formats takes more time for users with watermarking enabled. The delay is most significant on client workstations without hardware acceleration, where it can take up to the duration of a video sequence to export it. Hardware acceleration can greatly reduce the time required to export watermarked video. The performance gain varies with the graphics processing unit (GPU).
Any digital signatures and encryption in the video source are excluded from the exported file. In addition to Convert exported files, users need the Remove encryption privilege to export encrypted video with a watermark.
Limitations of video watermarking
The following video sources are not watermarked when viewed by a user with video watermarking enabled:
- Cached video files
- Media Gateway RTSP streams
- Thumbnails and alarm still frames
- Video previews for motion detection, security monitoring, and people counting
- Video accessed by the VideoSourceFilter of the Security Center Media SDK
- Video accessed by Config Tool and Security Desk version 5.8 and earlier