Protected Interoperable File Format
From Just Solve the File Format Problem
Protected Interoperable File Format (PIFF) is a multimedia format developed by Microsoft, and based on ISO Base Media File Format. Its main features are better support for multiple bitrates, and "improved" DRM.
Identification
PIFF files are identified by the brand "piff", which may be either a compatibility brand, or the primary brand. See Boxes/atoms format for a discussion of brands.
