M4P (MPEG-4 Protected) is a digital audio file extension for the AAC (Advanced Audio Codec) container format. It uses lossy compression and is an audio-only file. In most cases, M4P files are purchased on Apple iTunes, which means they are DRM-protected. M4A is the unprotected version of M4P.
DV (Digital Video) is a file created using a digital format and saved as raw data. A DV file contains 80-byte DIFs (Digital Interface Blocks), with each block having video, audio, and metadata. DVD files use lossy compression for videos, while sounds stay uncompressed. And although it was originally meant for tape recording, DV can also save data on hard disc drives and optical discs.
File Viewer Plus Apple iTunes QuickTime Player Adobe Audition CC 2019