Subtitles

Subtitles

Why subtitles?

Subtitles are a valuable accessibility feature for deaf and hard-of-hearing viewers, as well as those who may not be native speakers of the video's language. They can also be helpful for mobile viewers who often watch videos without sound.

You can add subtitles to your videos in the advanced editing area. Supported subtitle file formats include WEBVTT and .SRT, which are both W3C standards.

Use Subtitles

You can upload a single or multiple subtitle files whenever you use FTP to upload video files. The FTP upload is faster than uploading individual subtitle files through the VideoManager Pro web interface.

The subtitles function enables you to implement subtitles as closed captions in your videos, so that viewers can show or hide subtitles as needed.

You can add subtitles in the advanced editing area of uploaded videos.

Alternatively, you can automatically enable subtitles using the JavaScript API.

Subtitle file types

Only subtitle files in the .srt and .vtt formats are accepted

Additional properties in the XML file

To include subtitles, you must follow the format shown in the sample XML file below.

If you do not include the related subtitle file(s), the upload will fail. You must upload your files in this order: video file → subtitle file(s) → XML file.

Uploading multiple subtitle files with the same locale value is not supported. The video will be uploaded without subtitles.

<?xml version="1.0" encoding="UTF-8" ?>
<job xmlns="http://schemas.video-cdn.net/vmpro/public/v1/ingest/ftp/job.xsd" reference="mySubtitleVideo">
  <source>
    <file>video001.mp4</file>
  </source>
  <title>My Video With Subtitles</title>
  <subtitles>
    <subtitle>
      <file>subtitle_en.srt</file>
      <locale>en</locale>
    </subtitle>
    <subtitle>
      <file>subtitle_de.vtt</file>
      <locale>de</locale>
    </subtitle>
  </subtitles>
</job>

Locale information

Each subtitle property tag must include both the file and locale tags. Supported locale values are:

Trimming

If your video contains subtitles, you should be aware that trimming the video will not automatically adjust the subtitles. You will need to manually adjust the subtitles to ensure they are synchronized with the trimmed video.

To do this, you can download the subtitle file before trimming the video. Then, follow the steps above to trim the video. After trimming, you will need to manually adjust the subtitle files to ensure they are synchronized with the video.

Finally, upload the adjusted subtitle file once you have completed the synchronization process.

Adding Subtitles to Videos

Steps

To add subtitles to a video, follow these steps:

• Select the desired video in the video list and click the Advanced Video Editing button.

• In the navigation pane, select Subtitles.

• Click the Add subtitles button below the preview player.

  

• Select the language of your subtitles and upload the subtitle file.

• A new subtitle entry will be created for your selected language.

• To preview the subtitles, start the video in the preview player and click the cog icon. Select the desired subtitle language from the list.

  

• To change the language or description of a subtitle entry, click the entry in the list.

• To download a subtitle file, click the Download button next to the entry.

Once you have added subtitles to a video, an icon will be displayed beneath the video in the Video List. This icon helps you to keep track of which videos in your VideoManager Pro account have subtitles.

Subtitle General Settings

In the Subtitle General Settings overview, you can change the language definition, add a description, download the VTT/SRT subtitle files, or manually edit the single subtitle.

Automatically Generate Subtitles with VideoManager Pro

VideoManager Pro offers the ability to automatically generate subtitles using the VideoManager Pro AI service.

The resulting subtitles are displayed for a video the same way as uploaded subtitles are displayed.

After generating, a subtitle file in .VTT format is created and can then be downloaded. You can create subtitles for as many languages as you'd like, but only one set of subtitles can exist for each language at a time.

Set the Source Language

To generate subtitles, you first need to set the source language for your video. This tells the AI service which language to translate from.

• The source language is the language the audio of your video is in, not the language you want to create subtitles for.

• To set the source language, go to the video list and select the video you want to generate subtitles for.

• Click the Metadata accordion menu.

• In the Video Language field, select the language of your video from the drop-down menu.

  

• Click Save.

Generate the Subtitles

Once you've set the source language, you can generate subtitles.

• Go to the Advanced Video Editing area for your video.

• In the navigation pane, select Subtitles.

• Click the Add subtitles button below the preview player.

• Click the Generate tab.

  

• Select the language from the drop-down menu that you'd like to create subtitles for.

• Click Generate.

A new subtitles entry for your selected language will be created and displayed beneath the player. While your subtitle file is generating, a spinner will be displayed next to the subtitles name.

To preview a subtitle, start the video in the preview player. Click the cog wheel and select the name of the subtitles you'd like to see. To turn the subtitles off, select Off.

To improve the accuracy of your subtitles, minimize background sounds in your video and pronounce words clearly. This makes it easier for the AI service to understand and transcribe the audio. The more you use the AI service, the more it learns, and the better its transcription becomes over time.

Subtitle NOTE and Note of Confidence

Notes can be added to subtitle files by using the NOTE keyword or simply adding comments as a new line without any specific keyword. In automatically generated files, notes are added to each subtitle title with the addition of the confidence level.

A "Note of Confidence" is a metric used to indicate the level of certainty or accuracy of AI-generated subtitles. When an AI system transcribes audio into text, it assigns a confidence score to each word or phrase. This score reflects how likely it is that the transcription is correct based on the AI's analysis.

Example:

• High Confidence: If a word has a confidence score of 0.95, it means the AI is 95% certain that the transcription is accurate.

• Low Confidence: A confidence score of 0.60 indicates a lower level of certainty, suggesting that the word may need verification.

Creating and Editing Subtitles in VideoManager Pro

VideoManager Pro allows you to create and edit subtitles for your videos. You can use the subtitle editor to create new subtitles from scratch, or to make changes to existing subtitles.

Creating New Subtitles

To create new subtitles, follow these steps:

• Go to the Advanced Video Editing area for the video you want to add subtitles to.

• In the navigation pane, select Subtitles.

• Click the Add subtitles button below the preview player.

• Click the Create tab.

• Select the language for your subtitles from the drop-down menu.

• Play the video and click Add at current time or Add after last title to add subtitles at the desired timestamp.

• When you're finished, click Save.

Editing Existing Subtitles

To edit existing subtitles (either uploaded or generated), follow these steps:

• In the Subtitles management area, click the set of subtitles you want to edit.

• In the General Settings panel, click the Edit >> button. The subtitles editor will open.

• You will see a list of all the subtitles for your video, along with timestamps of when they appear. Clicking on a subtitle will make the preview player jump to the timestamp where it appears in the video.

• To add a new subtitle, click either the Add at current time or Add after last title buttons. An editing field will open where you specified.

• To edit an existing subtitle, double-click on the subtitle you want to edit to open the subtitle editor. An editing field will open with the subtitle you want to edit.

Using the Subtitle Editor

The subtitle editor allows you to set the timestamp for your subtitles, as well as add formatting styles. The buttons beneath the timestamp field are for the preview player.

• Play - Play the video in the preview player at the timestamp indicated.

• Repeat - Repeat the video in the preview player at the timestamp indicated.

• Delete - Delete the subtitle entry entirely.

To exit the editing field, click the grey X on the top right of the text box.