21. Profiles Advanced Main Simple Yes No No Display metadata Yes No No GOP Layer Yes No No Field and frame coding modes Yes Yes No Range adjustment Yes Yes No Intensity compensation Yes Yes No B frames Yes Yes No Adaptive macroblock quantization Yes Yes No Dynamic resolution change Yes Yes No Loop filter Yes Yes No Extended motion vectors Yes Yes No Start codes Yes Yes No ¼ pixel chrominance motion compensation Yes Yes Yes ¼ pixel luminance motion compensation Yes Yes Yes 4 motion vector per macroblock Yes Yes Yes Overlapped transform Yes Yes Yes 16-bit transform Yes Yes Yes Variable-sized transform Yes Yes Yes Baseline intra frame compression Advanced Main Simple
22. Comparison of H.264 and VC-1 Free. Reference encoder and decoder free as well. Plus JVT, M4IF mail- lists where one may receive answers on the AVC related questions. Not free. Reference decoder, which is not free by itself, comes with external documentation. FFMPeg project gives a free decoder. Documentation Similar Licensing costs Supports studio archiving requirements with 4:4:4 color space; separate black and white (BW) video mode Supports 4:2:0 compression / color space Example industry use Designed to meet a variety of industry needs with many profiles and levels, allowing for varying compression, quality and CPU usage levels, where the lowest level is for portable devices, designed with low CPU usage in mind, while the high levels are designed with very high quality and compression efficiency in mind Designed to offer very high image quality with excellent compression efficiency Goals H.264 VC 1 Overview
23. Comparison of H.264 and VC-1 6-tap filter for half pixel, averaging for quarter pixels bicubic, bilinear Sub pixel Interpolation methods Yes No B frame used for predicting other pictures Contiguous/non contiguous Contiguous (integer number of macro block rows only) Slice Yes VLC Only in High profile and above Yes Variable transform Size Only supported in Main and higher profiles No CABAC In-loop only In-loop and out-of-loop algorithms, overlap transform Deblocking filter SPS (sequence parameter set), PPS (picture parameters set), slice header, macroblock In advanced profile each Bit stream Data Unit has its own header. Simple and Main profile do not provide neither sequence nor entry point headers. Bitstream format NAL and byte stream single bit stream Bitstream formats H.264 VC-1 Features
24. Comparison of H.264 and VC-1 No data is encoded for macroblock Skipped Mb A field or frame Picture Two dimensional vector offset from current position to reference frame Motion vector 16x16 only Macroblock sizes Used for progressive or interlaced content Used for interlace content. Consists of bottom and top field Frame 4x4; 8x8 available in High Profile only 8x8, 4x8, 8x4, and 4x4 Integer transform 16x16, 16x8, 8x16, 8x8, 8x4, 4x8, and 4x4 16x16, 16x8, 8x16, and 8x8 Partition sizes H.264 VC-1 Feature