SMPTE / ST377-1-full-revision

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Differentiate correctly between the terms “Index Table” and “Index Table Segment #16

Open Rico-Z opened 6 years ago

Rico-Z commented 6 years ago

What is an Index Table? • An Index Table is a logical construct, it does not exist as KLV packet in an MXF file • An Index Table is the accumulation of Index Table Segmentsa

What is an Index Table Segment? • An Index Table Segment is a KLV packet that holds information about the distribution of (e.g. picture essence) frames in the corresponding essence stream

• An Index Table Segment may hold the byte-offset to each frame within the essence stream in the “Index Entry Array”.

The Standard does not always differentiate correctly between the terms “Index Table” and “Index Table Segment”, e.g.: “An Index Table may be placed in the Header Partition, in a Body Partition, in the Footer Partition” - SMPTE 377-1:2011, 11.1 Overview

There is no such thing as an Index Table that could be placed in either partition. Additionally, Index Tables (the accumulation of multiple Index Table Segments) are quite commonly distributed across several partitions in the case of Long-GOP picture essence.