maintainer Michael Niedermayer has criticised MPEG-4 for lacking an in-loop deblocking filter, GMC being too computationally intensive, and OBMC being defined but not allowed in any profiles among other things. Microsoft's Ben Waggoner states "Microsoft (well before my time) went down the codec standard route before with MPEG-4 part 2, which turns out to be a profound disappointment across the industry - it didn't offer that much of a compression advantage over MPEG-2, and the protracted license agreement discussions scared off a lot of adoption. I was involved in many digital media projects that wouldn't even touch MPEG-4 in the late 1990s to early 2000s because there was going to be a 'content fee' that hadn't been fully defined yet." Popular software implementations 3ivx DivX HDX4 libavcodec Nero Digital QuickTime Xvid See also High Efficiency Video Coding Advanced Video Coding Quantization (image processing) FourCC MP3 ISO/IEC JTC 1/SC 29 Notes External links MPEG-4 Part 2: Visual Official MPEG web site MPEG-4 Visual Patent List (MPEG LA) MPEG-4 Open standards covered by patents Videotelephony 1999 software 20th-century inventions