Telestream Becomes First Company to Add IMSC 1.0 Subtitle Support to Captioning Products


MacCaption, CaptionMaker, and Timed Text Flip Products now support new OTT subtitling standard required by major networks and online film distributors

Last Updated: April 4, 2017 1:07 pm GMT
(Nevada City, CA--April 4, 2017) Telestream®, a leading provider of digital media tools and workflow solutions, today announced that its entire suite of captioning and subtitling products now supports IMSC 1.0, the new OTT standard for subtitling and captioning. For major networks and content distributors standardizing on the IMF file-based delivery format, such as Netflix, delivering subtitles for streaming content with IMSC 1.0 Timed Text is a requirement.

“Whether creating subtitles with our MacCaption or CaptionMaker software, or automating subtitle conversion with the Timed Text Flip module in Vantage, Telestream is the first company to create, edit, extract, and automate with the IMSC 1.0 Timed Text specification,” said Giovanni Galvez, Product Manager for Telestream Captioning and Subtitling Software. “We also have the only IMSC 1.0 solution that can be integrated with existing transcode workflows.”

Assured Compliance with Accessibility Mandates
Government legislation in a growing number of countries requires broadcasters to deliver closed captioning and subtitles to Internet outlets. However, compliance can sometimes introduce manual processes and time-consuming workarounds into workflows that were otherwise automated. With the addition of IMSC 1.0 in Timed Text Flip, Vantage users can work with caption or subtitle data inside the same automated workflow they rely on every day.

Customers can now automatically convert common caption/subtitle files to IMSC 1.0 Timed Text from archives of old caption and subtitle files. Any supported caption/subtitle file type can be extracted and converted via watch folders, API, or simple drag and drop operations. IMSC 1.0 is now available as a master caption or subtitle format in any Telestream workflow.

“At PBS we are very focused on integrating Internet and broadcast efforts, and to that end, we are supporting the IMSC 1.0 caption and subtitle format, a key element of the emerging ATSC 3.0 and IMF standards being used for both broadcast and broadband applications. The standard is a technological advancement over current 608/708 caption standards and facilitates a more diverse range of languages, including those requiring image-based fonts. Being able to leverage a single file for both broadcast and OTT delivery is a huge step forward in streamlining file-based workflows, and one of the more significant benefits of the ATSC 3.0 and IMF standards,” said Chris Homer, VP Engineering at PBS.

Benefits of IMSC Support:
  • Pass validation to comply with IMSC 1.0 specification
  • Start delivering IMSC 1.0 without changing your existing workflow
  • Automate and quickly migrate to IMSC 1.0 from archived files
  • Export a subtitle format compatible with IMF

In addition to IMSC 1.0 workflows, export now includes options for iTunes .iTT subtitles along with new support for Teletext OP-47 and OP-42 for Australian and European broadcasters.

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About Telestream
Telestream provides world-class live and on-demand digital video tools and workflow solutions that allow consumers and businesses to transform video on the desktop and across the enterprise. Many of the world’s most demanding media and entertainment companies as well as a growing number of users in a broad range of business environments, rely on Telestream products to streamline operations, reach broader audiences and generate more revenue from their media. Telestream products span the entire digital media lifecycle, including video capture and ingest; live and on-demand encoding and transcoding; captioning; playback and inspection, delivery, and live streaming; as well as automation and orchestration of the entire workflow. Telestream corporate headquarters are located in Nevada City, California. The company is privately held. For company and product information, visit

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