Kartra Documentation TECHNICAL DOCUMENTATION

Closed captions

You may upload a text transcript of your video and Kartra will display the closed captions as the video plays along. This will help users with hearing impediments to read through your video content, by simply activating the Closed Caption icon in the video player.

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The crucial point in this process is to create a file containing the text transcript correctly. Read this fantastic article to learn the full technical walk-through, but here below you will find a quick summary.

 

Writing the video transcript

Firstly, open a standard .txt file with the NotePad (Windows) or TextEdit (Mac) application. Here’s a sample of how to format the contents inside that text file:

WEBVTT

00:00:01.000 –> 00:00:03.000 align:center line:90% size:80%
Hello world first!

00:00:05.000 –> 00:00:10.000 align:center line:90% size:80%
Hello world second!

 

This quick file will overlay on the video the following lines:

  • Hello world first!” from second 1 to second 3 of the video
  • Hello world second!” from second 5 to second 10 of the video.

Important things to keep in mind:

  • Please leave the align:center line:90% size:80% part as it is, because that defines the location of the text within the video player.
  • The time format parameters (hours : minutes : seconds) must always be represented as a 2-digit parameter. For example: 00:00:010.000 will NOT be read as 10 seconds. The proper format for 10 seconds should be 00:00:10.000. If you want to represent 5 seconds, the correct format would be 00:00:05.000, NOT 00:00:5.000 .
  • The “arrow symbol” (example: 00:00:01.000 –> 00:00:03.000) is constructed by two standard dashes (– –), not one long dash ().

From there on, you would add more and more lines into the file, at the corresponding time interval, until you cover the entire video transcript

 

Converting the file into the right format

This type of video transcript must be saved in .vtt filename extension:. Creating a .vtt file is actually very easy:

  1. Once you have completed the text file on NotePad or TextEdit and you save it in .txt extension, you would simply need to rename the file changing the .txt extension into .vtt . For example, renaming MyVideoTranscript.txt into MyVideoTranscript.vtt .
  2. Upload the .vtt file through the Kartra Video interface. See screenshot below.

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Finally, you may download this sample .vtt file to have an idea of what they look like. Feel free to edit it at will!

Optimize your videos

While chances are that your video recording camera or phone might record your video files at full HD resolution (even 4K!) and 60 frames per second, the truth is those extreme settings might actually ruin the video experience for your users! You see, some of your viewers might not have a pristine internet connection, or they might be watching on the go from their mobile phone, or perhaps from a hotel room, etc.

The point is that you want to lean down those huge video files so your viewers don’t suffer from constant buffering downtimes. Remember, this is supposed to be a browser-based web video, not a Netflix show watched from a 65-inch TV!

The good thing is that there’s a free software called HandBrake that will re-encode and optimize your videos, making them much leaner and without losing any quality at all.

Here are the recommended settings for the optimal balance between HD quality and fast streaming:

  • MP4 format
  • 720p resolution at 30 frames per second
  • Web optimized option ticked ON
  • Audio bitrate set at 128

The following video overviews the whole configuration process:

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