It seems that MPEG-1 Layer 3 patents are mostly expired, the core patents for MPEG-2 will expire in 2016-2018, but MPEG-4 MPEGLA patents are safe till 2025-2027.
Also if the patents expire the organizations loses it&#x27;s ability to collect royalties for the codec it self from what i understand so if that would&#x27;ve been the case there&#x27;s little need to create a new codec 
but MPEG4&#x2F;AVC patent protection seem to remain quite strong for about another decade.<p>The MPEG4 licensing scheme is kinda confusing to me it seems that several organizations collect royalties individually even tho it states that MPEGLA collects them in the US, AT&amp;T seems to do so too for their share of the patents.