Which OCI speech feature should be used to add closed captions for accessibility in videos?

The feature that should be used to add closed captions for accessibility in videos is SRT file support. This option stands out because SubRip Subtitle (SRT) files are widely used for closed captioning and can be integrated into video content to provide text representation of spoken dialogue. This support allows content creators to prepare and display captions, which enhance accessibility for deaf or hard-of-hearing audiences.

Transcription Service and Speech Recognition are useful in converting spoken language into text, but they do not inherently create subtitle files needed for video playback. These services might be part of the processes involved in generating the content that ultimately gets formatted as an SRT file, but on their own, they do not offer a direct method for implementing closed captions in video.

Live Streaming refers to the real-time broadcasting of video content and while it can include closed captions, it does not specifically address the creation of subtitle files for pre-recorded content, which is the context implied by the question about adding closed captions.

Thus, SRT file support is the definitive feature for adding structured, accessible captions to video, providing an essential resource for enhancing viewer accessibility and experience.