ProtocolTracker Pro od KimSa

ProtocolTracker Pro Firefox addon provides convenient tracking of playlist and subtitle URLs across Apple HLS, Adobe HDS, MPEG-DASH, and Microsoft Smooth Streaming protocols. It enables direct video/audio file downloads and monitoring of other file extensions and Content-Type headers.

Additional options:

Instantly copy URLs by clicking filenames in the addon's popup menu.
headers for streamlined stream downloading.
Customize settings in the options page to facilitate direct media file downloads.