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Conformance testing

Standard: 
Part number: 
4
Activity status: 
Closed
Technologies: 

MPEG-2 Conformance

 

MPEG doc#: N7647
Date: Oct. 2005
Author:

 

Parts 1, 2 and 3 of ISO/IEC 13818 specify a multiplex structure and coded representations of audio-visual information. Parts 1, 2 and 3 of ISO/IEC 13818 allow for large flexibility, achieving suitability of ISO/IEC 13818 for many different applications. The flexibility is obtained by including parameters in the bitstream that define the characteristics of coded bitstreams. Examples are the audio sampling frequency, picture size, picture rate and bitrate parameters.

This part of ISO/IEC 13818 specifies how tests can be designed to verify whether bitstreams and decoders meet the requirements as specified in parts 1, 2 and 3 of ISO/IEC 13818. These tests can be used for various purposes such as:

  • manufacturers of encoders, and their customers, can use the tests to verify whether the encoder produces valid bitstreams.
  • manufacturers of decoders and their customers can use the tests to verify whether the decoder meets the requirements specified in parts 1,2 and 3 of ISO/IEC 13818 for the claimed decoder capabilities.

This part of ISO/IEC 13818 specifies how tests can be designed to verify whether bitstreams and decoders meet requirements specified in parts 1, 2 and 3 of ISO/IEC 13818. In this part of ISO/IEC 13818, encoders are not addressed specifically. An encoder may be said to be an ISO/IEC 13818 encoder if it generates bitstreams compliant with the syntactic and semantic bitstream requirements specified in parts 1, 2 and 3 of ISO/IEC 13818.

Characteristics of coded bitstreams and decoders are defined for parts 1, 2 and 3 of ISO/IEC 13818.

The characteristics of a bitstream define the subset of the standard that is exploited in the bitstream.  Examples are the applied values or range of the picture size and bitrate parameters. Decoder characteristics define the properties and capabilities of the applied decoding process. An example of a property is the applied arithmetic accuracy. The capabilities of a decoder specify which coded bitstreams the decoder can decode and reconstruct, by defining the subset of the standard that may be exploited in decodable bitstreams. A bitstream can be decoded by a decoder if the characteristics of the coded bitstream are within the subset of the standard specified by the decoder capabilities.  Procedures are described for testing conformance of bitstreams and decoders to the requirements defined in parts 1, 2 and 3 of ISO/IEC 13818. Given the set of characteristics claimed, the requirements that must be met are fully determined by parts 1, 2 and 3 of ISO/IEC 13818. This part of ISO/IEC 13818 summarises the requirements, cross references them to characteristics, and defines how conformance with them can be tested. Guidelines are given on constructing tests to verify bitstream and decoder conformance. This document gives guidelines on how to construct bitstream test suites to check or verify decoder conformance. In addition, some test bitstreams implemented according to those guidelines are provided as an electronic annex to this document.

Reference

MPEG-2 

 13818-4:2004

Part 4: Conformance testing

Bitstreams