I find working solution for my Raspberry PI B+. Now my IPTV channels plays well without any problems.
FYI: i use OSMC with pvr.iptvsimple enabled.
Don’t waste your time for changing something with advancedsettings.xml — it’s not change anything! No OSMC «tweaks» can’t help you too.
Just go here and buy MPEG-2 codecs licence key!
Simple solution only for £2.00.
When you get key value(it’s not immediately — for me it’s took four hours) to your email, you can easy add it in Programs > My OSMC > [PI icon] > GPU Mem & Codecs.
Then restart your OSMC and enjoy your TV!:)