IDR and non IDR difference

Question

What is the difference between IDR and non IDR frames?

What are "coded slice of non IDR picture" , "Coded slice Data partition A", "Coded slice Data partition B", "Coded slice Data partition C", "Coded slice of an IDR picture" ?

Answer 1

IDR, slices, partitioning - you have them all defined formally right there in specification:

3 Definitions

3.62 instantaneous decoding refresh (IDR) picture: A coded picture in which all slices are I or SI slices that causes the decoding process to mark all reference pictures as "unused for reference" immediately after decoding the IDR picture. After the decoding of an IDR picture all following coded pictures in decoding order can be decoded without inter prediction from any picture decoded prior to the IDR picture. The first picture of each coded video sequence is an IDR picture.

3.27 coded picture: A coded representation of a picture. A coded picture may be either a coded field or a coded frame. Coded picture is a collective term referring to a primary coded picture or a redundant coded picture, but not to both together.

3.136 slice: An integer number of macroblocks or macroblock pairs ordered consecutively in the raster scan within a particular slice group. For the primary coded picture, the division of each slice group into slices is a partitioning. Although a slice contains macroblocks or macroblock pairs that are consecutive in the raster scan within a slice group, these macroblocks or macroblock pairs are not necessarily consecutive in the raster scan within the picture. The addresses of the macroblocks are derived from the address of the first macroblock in a slice (as represented in the slice header) and the macroblock to slice group map.

3.137 slice data partitioning: A method of partitioning selected syntax elements into syntax structures based on a category associated with each syntax element.