Dear Support,
I have problem vith live TV aspect ratio, so I have contacted Silicondust to get help.
Here you can find they answer, so Plex has to be fixed:
Dear Miklós,
The video is encoded at 1440x1080 by the broadcaster, but is marked in the video stream as 16:9, which means the player should stretch it to 16:9 to make it look normal, similar to how widescreen DVDs worked. Plex fails to honor this flag and plays it at whatever the ratio of the pixels is, which ends up as 4:3. This is a bug in Plex and would need to be fixed by Plex.
You should report the issue to Plex via the Plex forums at https://forums.plex.tv . They may want a sample recording of one of those channels from you to provide to their development team.
- Silicondust Support
Ticket ID: #109585
Waiting for your reply.
Regards,
Miklós