What did MPEG-2 add to MPEG-1 in terms of syntax/algorithms?
A. Here is a brief summary: Sequence layer: More aspect ratios. A minor, yet necessary part of the syntax. Horizontal and vertical dimensions are now required to be a multiple of 16 in frame coded pictures, and the vertical dimension must be a multiple of 32 in field coded pictures. 4:2:2 and 4:4:4 macroblocks were added in the Next profiles. Syntax can now signal frame sizes as large as 16383 x 16383. Syntax signals source video type (NTSC, PAL, SECAM, MAC, component) to help post-processing and display. Source video color primaries (609, 170M, 240M, D65, etc.) and opto- electronic transfer characteristics (709, 624-4M, 170M etc.) can be indicated. Four scaleable modes [see scalability discussion] Picture layer: All MPEG-2 motion vectors are specified to a half-pel sample grid. DC precision can be user-selected as 8, 9, 10, or 11 bits. New scalar quantization matrices may be downloaded once per picture. In High profile, separate chrominance matrices now exist (Y and C no longer have t
