How are interlaced and progressive pictures indicated in MPEG?
The following tree may help illustrate the possible layers of progressive and interlaced coding modes. Progressive and interlace bear themselves at different layers of the MPEG bitstream, not just the picture layer. MPEG-2 sequence / \ progressive interlaced sequence sequence / \ Field picture Frame picture / \ Frame or field prediction Frame MB / \ Field dct Frame dct What does it mean to be compliant with MPEG. other than paying your patent royalties ? There are two areas of conformance/compliance in MPEG: 1.Compliant bitstreams 2.Compliant decoders Technically speaking, video bitstreams consisting entirely of I-frames are syntactically compliant with the MPEG specification. The I-frame sequence simply utilizes a rather limited subset of the full syntax. Compliant bitstreams must obey the range limits (e.g. motion vectors ranges, bit rates, frame rates, buffer sizes) and permitted syntax elements in the bitstream (e.g. chroma_format, B-pictures, etc). Decoders, however, must be able
