SRT Files

Overview

SRT files, or SubRip Subtitle files, are one of the most common file formats for displaying subtitles on web video content. They are simple text files that contain timecodes, indicating when each subtitle should appear and disappear on screen. The text in the file does not require specialized software to open or edit.

Structure

SRT files follow a specific structure:

1. Sequence Number – Indicates the numeric order of each subtitle.
2. Timecodes – Specify when the subtitle starts and stops. The format is hours:minutes,milliseconds (e.g., 00:01:15,000 --> 00:01:18,000).
3. Text – The subtitle text that will appear on screen.

Here is a basic example of the formatting found in a .srt file:

1 
00:00:01,150 --> 00:00:03,220 
Hey, did you know SRT files were developed in France?

2 
00:00:03,220 --> 00:00:07,140 
Oh cool! Is that why the comma is used as a decimal?

3 
00:00:08,050 --> 00:00:10,810 
Yep! They can be opened and edited in virtually any text program.

Social

SRT files are primarily used to provide subtitles for video content on social media platforms like YouTube, Facebook, or LinkedIn. Social platforms allow for SRT files to be uploaded separately alongside a video file. The video player allows users on the platform to toggle the subtitle track on and off.

Linear

SRT files are not suitable for linear, as this format lacks the necessary functionality and compatibility with broadcast closed captioning.

Supplying an SRT to XR for broadcast requires retiming and reformatting to create the closed captioning, which is essentially the same as supplying a well formatted script.

The recommended method of supplying closed captions for linear use is as an embedded data track in the source video file. See these articles for more information:

• https://helpcenter.xr.global/hc/en-us/articles/5758928813332-North-America-TV-Video-Specifications
• https://helpcenter.xr.global/hc/en-us/articles/5760339463444-North-American-Closed-Captioning-Requirements
• https://helpcenter.xr.global/hc/en-us/articles/23849688617876-Accessibility-Services-TV

Digital

Digital platforms currently do not support closed captioning or subtitling for ads. As a result, advertisers often burn captions directly into the video (a process called "burned-in" or "hardcoded" subtitles).

The Video Ad Serving Template (VAST) standard introduced support for caption files in version 4.1. However, even publishers who have adopted this standard have yet to include support for closed captioning.