Speech to Text Workflow Operation

ID: speechtotext

Description

The speech to text operation can be used to generate subtitles for Videos or Audio files. Currently, there is only Vosk available as STT Engine. The subtitles file format ist WebVTT.

Parameter Table

configuration keys	required	description
source-flavor	yes	The source media package to use
target-flavor	yes	Flavor of the produced subtitle file. The subflavor supports the language-code placeholder #{lang}
target-element	no	Define where to append the subtitles file. Possibilities are: as a 'track' or as an 'attachment'. The default is "attachment".
language-code	no	The language of the video or audio source (default is "eng"). It has to match the name of the language model directory. See 'vosk-cli'.
language-fallback	no	The fallback value if the dublin core/media package language field is not present. (default is "eng")
target-tags	no	Tags for the subtitle file

Requirements

In order for it to work, you have to install the vosk-cli package. Installation instructions can be found at github.com/elan-ev/vosk-cli.

Operation Examples

If you want to display the subtitles in the Paella player, the WebVTT files have to be published and the target SubFlavor has to be configured like this: vtt+LANG, where LANG is the language option, that will be displayed in the Paella player. Please note the description above for the language-code field.

<operation
    id="speechtotext"
    description="Generates subtitles for video and audio files">
  <configurations>
    <configuration key="source-flavor">*/source</configuration>
    <configuration key="target-flavor">captions/vtt+en</configuration>
    <configuration key="target-element">attachment</configuration>
    <configuration key="target-tags">archive,subtitle,engage-download</configuration>
    <configuration key="language-code">eng</configuration>
  </configurations>
</operation>

<operation
    id="speechtotext"
    description="Generates subtitles for video and audio files, derive language-code from metadata">
    <configurations>
      <configuration key="source-flavor">*/source</configuration>
      <configuration key="target-flavor">captions/vtt+#{lang}</configuration>
      <configuration key="target-element">attachment</configuration>
      <configuration key="target-tags">archive,subtitle,engage-download</configuration>
    </configurations>
</operation>