---
title: Media Decoding
framework: Private Cloud Compute Security Guide
role: article
role_heading: Article
path: private-cloud-compute/mediadecoding
---

# Media Decoding

A dedicated PCC worker decodes untrusted compressed video and images into pixel buffers, isolated from the workflows that consume them.

## Overview

Overview Some PCC Agent workflows operate on compressed media, such as the HomeKit Secure Video Analysis workflow. Decoding compressed video and images means parsing byte streams with system code that implements a codec (coder/decoder) defined by a complex specification. That complexity gives an attacker an opportunity to exploit vulnerabilities in the codec implementation. To contain that risk, PCC does not decode media inside the workflow process. Instead, a workflow hands the compressed bytes to a dedicated media decode worker through a Delegated tool calls and receives back uncompressed pixel buffers or other safe formats. Media decoder in PCC architecture PCC Agent provides two tools for media decoding: VideoDecodingTool for video and ImageDecodingTool for images. The decoder runs on dedicated PCC nodes as the PCCMediaDecoder cloud application. Supported formats The decoder currently accepts: Security properties The compressed media that a workflow hands to the decoder is untrusted input. We treat this decode step as its own attack surface and apply multiple defenses to hinder exploitation and contain any compromise: