Convert STM to XML

Understanding stm and xml file formats

STM files, commonly known as Segment Time Marked files, are used in speech and language processing to annotate audio data with time-aligned transcriptions. These files are plain text and follow a specific structure to indicate speaker turns, start and end times, and the spoken content.

XML (eXtensible Markup Language) is a widely used markup language for storing and transporting structured data. XML files are both human- and machine-readable, making them ideal for data exchange between different systems and applications.

Why convert stm to xml?

Converting STM files to XML format allows for easier integration with modern data processing tools, databases, and web applications. XML's structured nature makes it suitable for further analysis, transformation, or sharing across platforms.

How to convert stm to xml

There is no direct, universal converter for STM to XML, but you can use scripting languages like Python to automate the process. Here’s a general approach:

1. Read the STM file line by line.
2. Parse each line to extract fields such as filename, channel, speaker, start time, end time, and transcript.
3. Structure the extracted data into XML elements.
4. Write the output to an XML file.

For those less comfortable with scripting, some speech annotation tools can export to XML, but may require manual mapping.

Recommended software for stm to xml conversion

• Python with ElementTree or lxml: Write a custom script to parse STM and generate XML. This is the most flexible and reliable method.
• ELAN: Import STM files and export annotations as XML. Use File → Import → STM and then File → Export As → EAF (XML).
• Praat: While primarily for audio analysis, Praat can import STM and export TextGrid, which can be converted to XML with additional tools.

Sample python script for stm to xml conversion

import xml.etree.ElementTree as ET

def stm_to_xml(stm_path, xml_path):
    root = ET.Element('Transcripts')
    with open(stm_path, 'r') as stm_file:
        for line in stm_file:
            parts = line.strip().split()
            if len(parts) < 6:
                continue
            entry = ET.SubElement(root, 'Segment')
            ET.SubElement(entry, 'File').text = parts[0]
            ET.SubElement(entry, 'Channel').text = parts[1]
            ET.SubElement(entry, 'Speaker').text = parts[2]
            ET.SubElement(entry, 'StartTime').text = parts[3]
            ET.SubElement(entry, 'EndTime').text = parts[4]
            ET.SubElement(entry, 'Transcript').text = ' '.join(parts[5:])
    tree = ET.ElementTree(root)
    tree.write(xml_path, encoding='utf-8', xml_declaration=True)

This script reads an STM file and outputs a structured XML file.

Conclusion

Converting STM files to XML is best achieved using Python scripting or specialized linguistic annotation tools like ELAN. This enables better data interoperability and further processing.