The containing playlist supplies the base
If a playlist is at https://media.example/live/main.m3u8, an entry of part 1.ts normally resolves under /live/. An entry beginning with /shared/ instead starts from the host root. A complete https address supplies its own host and path. These address forms are not interchangeable.
In a multi-level presentation, a master playlist first points to a media playlist; the media playlist then supplies the base for its own entries. The original website page is not automatically the base for every nested segment. Understanding that hierarchy is essential when a copied master loads but its media does not.
A safe illustrative move
Imagine copying /live/main.m 3 u 8 to /support/main.m 3 u 8 while preserving an entry called video/segment 1.ts. Its resolved path changes from /live/video/segment 1.ts to /support/video/segment 1.ts. If the media was never copied, the second address can fail even though the text file is identical.
This explains why downloading a playlist onto a computer is not the same as downloading the whole presentation. Local file location and network location introduce different bases and permissions. A successful text download says little about the reachability of nested dependencies.
Debug the resolved request
When reporting a missing segment, the useful evidence is the resolved resource location and response status, with private components removed. A publisher can compare that location with the intended packaging structure. Looking only at the short relative line can miss an incorrect base or a changed redirect destination.
Use examples with reserved example domains in public explanations. Do not paste account URLs into public URL-resolution services, because the query or path may contain access credentials. For a viewer, the approved original playlist address is generally a better comparison than a manually relocated copy.
Questions about this guide
Does saving an M3U8 file save its media too?
No. It saves the text response unless a separate authorised process retrieves its dependencies.
What resolves a relative segment address?
The URI of the media playlist containing that entry, under normal URI-resolution rules.