Add subtitle

Add new subtitle/captions to a video entity.

Add already exist subtitles Subtitles must be in one of the following formats:

• SRT – SubRip Text is described on wikipedia.org. Must start from integer for sequence number. Use calidators to check the subtitles, like srt-validator.
• WebVTT – Web Video Text Tracks Format is described on developer.mozilla.org. Must start from “WEBVTT” header. Use validators to check the subtitles, like W3C. Language is 3-letter language code according to ISO-639-2 (bibliographic code). Specify language you need, or just look at our list in the attribute “audio_language” of section “AI Transcribe”. You can add multiple subtitles in the same language, language uniqueness is not required. Size must be up to 5Mb.

The update time for added or changed subtitles is up to 30 seconds. Just like videos, subtitles are cached, so it takes time to update the data.

AI subtitles and transcribing It is also possible to automatically create subtitles based on AI. Read more:

• What is “AI Transcribe”.
• If the option is enabled via auto_transcribe_audio_language: auto|, then immediately after successful transcoding, an AI task will be automatically created for transcription.
• If you need to translate subtitles from original language to any other, then AI-task of subtitles translation can be applied. Use auto_translate_subtitles_language: default| parameter for that. Also you can point several languages to translate to, then a separate subtitle will be generated for each specified language. The created AI-task(s) will be automatically executed, and result will also be automatically attached to this video as subtitle(s). If AI is disabled in your account, you will receive code 422 in response.

Where and how subtitles are displayed? Subtitles are became available in the API response and in playback manifests. All added subtitles are automatically inserted into the output manifest .m3u8. This way, subtitles become available to any player: our player, OS built-in, or other specialized ones. You don’t need to do anything else. Read more information in the Knowledge Base. Example:

#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subs0",NAME="English",LANGUAGE="en",AUTOSELECT=YES,URI="subs-0.m3u8"