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INTRODUCTION

regxmllib is a collection of tools and libraries for the creation of RegXML (SMPTE ST 2001-1) representations of MXF header metadata (SMPTE ST 377-1). A RegXML Fragment example can be found at [1]

[1] src/test/resources/reference-files

Two implementations of regxmllib are provided:

• regxmllibj, which is implemented in pure Java; and
• regxmllibc, which is implemented in C++03.

KNOWN ISSUES AND LIMITATIONS

regxmllib relies on SMPTE Metadata Registers that conform to SMPTE ST 335, ST 395, ST 400, ST 2003. These registers are published at [1].

[1] https://smpte-ra.org/smpte-metadata-registry

regxmllib deviates from ST 2001-1:2013 in a few narrow instances. Such deviations are noted in the source code and are expected to be submitted for consideration at the next revision of ST 2001-1. In particular:

• no baseline metadictionary is used, instead one extension metadictionary per namespace is used

Bugs are tracked at [2]

[2] https://github.com/sandflow/regxmllib/issues

REGXMLLIBJ

Prerequisites

Java 11 and above

Maven

(recommended) Git

(recommended) SMPTE Metadata Registers (Types, Elements, Groups and Labels)

Quick Start

The following outputs to path PATH_TO_FRAGMENT an XML representation of the header metadata of the MXF file at path PATH_TO_MXF_FILE

• mvn package -Pwith-dependencies

• choose one of the following:

  • OPTION 1

    • retrieve the four SMPTE Metadata Registers (see [1] above)

    • build the metadictionaries from the SMPTE registers

      java -cp <PATH_TO_JAR> com.sandflow.smpte.tools.XMLRegistersToDict -e <PATH_TO_ELEMENTS_REG> -l <PATH_TO_LABELS_REG> -g <PATH_TO_GROUPS_REG> -t <PATH_TO_TYPES_REG> PATH_TO_DICT_DIR

  • OPTION 2

    • retrieve metadictionaries from [3]

      [3] https://github.com/sandflow/IMF/tree/master/dict

• generate the RegXML fragment

  run java -cp target/regxmllib-jar-with-dependencies.jar com.sandflow.smpte.tools.RegXMLDump -all -d <PATH_TO_DICT1> <PATH_TO_DICT2> ... -i <PATH_TO_MXF_FILE> > <PATH_TO_FRAGMENT>

• (optional) generate XSDs for RegXML Fragments

  run java -cp target/regxmllib-jar-with-dependencies.jar com.sandflow.smpte.tools.GenerateDictionaryXMLSchema -d <PATH_TO_DICT1> <PATH_TO_DICT2> ... -o <PATH_TO_OUTPUT_DIR>

• (optional) generate XSDs for SMPTE registers

  run java -cp target/regxmllib-jar-with-dependencies.jar com.sandflow.smpte.tools.GenerateXMLSchemaDocuments -cp <CLASS_PATH_TO_REGISTER_MODEL> -d <PATH_TO_OUTPUT_DIR>

  where <CLASS_PATH_TO_REGISTER_MODEL> is equal to com.sandflow.smpte.register.catsup.TypesRegisterModel, etc.

Architecture

At the heart of regxmllib is the FragmentBuilder.fragmentFromTriplet() method that creates an XML fragment from a KLV group given a a RegXML metadictionary and a collection of KLV groups from which strong references are resolved. The rules engine implemented in FragmentBuilder.fragmentFromTriplet() is intended to follow the rules specified in ST 2001-1 as closely as possible. A sister method, XMLSchemaBuilder.fromDictionary(), creates a matching XML Schema that can be used to validate RegXML fragments.

Metadictionaries can be imported and exported from XML documents that conform to the schema specified in SMPTE ST 2001-1. They can also be created from SMPTE Metadata Registers published in XML form.

regxmllib includes a minimal MXF and KLV parser library.

Packages

com.sandflow.smpte.klv : Classes for processing SMPTE KLV triplets (ST 336)

com.sandflow.smpte.mxf: Classes for processing SMPTE MXF structures (ST 377-1)

com.sandflow.smpte.register: Classes for processing SMPTE metadata registers (ST 335, ST 395, ST 400, ST 2003)

com.sandfow.smpte.regxml: Classes for managing RegXML metadictionaries and creating RegXML representations of MXF structures

com.sandfow.smpte.tools: Application-level tools

com.sandfow.smpte.util: Utilities classes

Tools

RegXMLDump: dumps either the first essence descriptor or the entire header metadata of an MXF file as a RegXML structure

XMLRegistersToDict: converts XML-based SMPTE metadata registers to a RegXML metadictionaries

GenerateXMLSchemaDocuments: generates XSDs for the SMPTE metadata registers

GenerateDictionaryXMLSchema: generate XSDs for RegXML Fragments from the RegXML metadictionaries

Unit Test

Unit testing is performed by generating RegXML fragments from sample files located at [1] and registers located at [2]. The resulting RegXML fragments are compared to reference RegXML fragments located at [3].

[1] src/test/mxf-files [2] src/test/registers [3] src/test/regxml-files

Reference RegXML fragments can regenerated by running the package goal with the build-reference-test-files profile:

mvn package -Pbuild-reference-files

Maven Artifacts

• GroupId com.sandflow
• ArtifactId regxmllib

Snapshots are deployed at https://oss.sonatype.org/content/repositories/snapshots/

Releases are deployed at the central repository

REGXMLLIBC

Prerequisites

C++03 toolchain

Metadictionaries generated by regxmllibj (see Building Metadictionaries above)

Xerces-C++ Version 3.1.4 (or above) [1]

(recommended) CMake

[1] https://xerces.apache.org/xerces-c/

Architecture

regxmllibc generally follows the architecture and idioms of regxmllibj.

Applications will typically call FragmentBuilder::fromTriplet() or MXFFragmentBuilder::fromInputStream(), and the unit test at [1] provides an example.

[1] src/test/cpp/com/sandflow/smpte/dict/MetaDictionaryTest.cpp

regxmllibc does not however support the conversion of the SMPTE Metadata Registers to RegXML metadictionaries, and instead relies on the metadictionaries generated by regxmllibj (see Building Metadictionaries above).

Unit Test

As with regxmllibj, unit testing is performed by generating RegXML fragments from sample files located at [1] and reference metadictionaries located at [2]. The resulting RegXML fragments are compared to reference RegXML fragments located at [3].

[1] src/test/mxf-files [2] src/test/regxml-dicts [3] src/test/regxml-files

DIRECTORIES AND NOTABLE FILES

build.xml Helper script (Ant)

pom.xml Maven POM file

CMakeLists.txt CMake build file

target Output of the Maven build process, including the JAR

src/java regxmllibj codebase

src/cpp regxmllibc codebase

src/main/config/repoversion.properties Template Java properties file used to host the a unique source code version generated using git by the build system

src/main/resources/reg.xsd Common XML Schema definitions used when generating XML Schemas for RegXML Fragments

src/test/resources/regxml-files Reference RegXML fragment used for unit testing

src/test/resources/registers Reference SMPTE registers used for unit testing

src/test/resources/mxf-files Sample MXF files used for unit testing

src/test/resources/regxml-dicts Reference metadictionaries used for unit testing