---
title: "Watermark Preprocessing"
description: "This document describes how to preprocess in a cloud-based packaging service or with an encoder integration."
---
> For the complete documentation index, see [llms.txt](https://docs.doverunner.com/llms.txt).

In order to apply watermark to a source video, a preprocessing operation is required in the content encoding process. A watermark value (0 and 1) is inserted in the original uncompressed video frame to generate output as two sets of encoded video. (A/B variants)

The inserted watermark value is encrypted using a secret key unique to each content service provider, and can not be extracted from the outside arbitrarily.

```mermaid
flowchart LR
  subgraph grp_a["DoveRunner forensic watermarking"]
    D@{ icon: "watermark", form: "square", h: 72, label: "Watermark 0 and 1" }
  end
  A@{ icon: "video", form: "square", h: 72, label: "Source frame" } --> B@{ icon: "plugin", form: "square", h: 72, label: "Watermark Preprocessor" }
  B --> C@{ icon: "variants", form: "square", h: 72, label: "Two sets of watermarked frame (0 and 1)" }
  D -->|Secret key| B
```

The watermark preprocessing can be done using one of the following options depending on the customer's choice.

- [FWM Preprocessing through T&P Service](https://docs.doverunner.com/content-security/forensic-watermarking/preprocessing/fwm-tnp-service/)
  Pre-processing of forensic watermarking contents can be performed through DoveRunner Transcoding & Packaging service.
- [Preprocessor Library Guide](https://docs.doverunner.com/content-security/forensic-watermarking/preprocessing/preprocessor-library/)
  DoveRunner Preprocessor Library is a watermark preprocessor implemented as a C ++ library so that it can be ported to an encoding solution. This document explains how to use the Preprocessor Library.
- [FFmpeg Preprocessor Filter Guide](https://docs.doverunner.com/content-security/forensic-watermarking/preprocessing/ffmpeg-filter/)
  A plug and play module capable of watermark preprocessing as a video filter for FFmpeg.
- [FWM Hybrik Preprocessor Guide](https://docs.doverunner.com/content-security/forensic-watermarking/preprocessing/hybrik-preprocessor/)
  DoveRunner FWM Hybrik preprocessor is a module that can perform forensic watermarking preprocessing during video transcoding through Dolby Hybrik service.