In addition to using Livestream Studio, there are some closed captioning options that have worked successfully with the Livestream player thanks to improvements with live encoders and cloud services.
Generally speaking, if an encoder can stream via RTMP and transmit CEA-608 closed captions either via SDI or a cloud service, those captions will be available in the Livestream live player as well as in the stream’s archive. Please note that we cannot control how captions will appear in another provider's player when simulcasting to another destination.
You should work with your encoder’s manufacturer or captioning provider on your configuration to ensure your stream will output CEA-608 captions to the Livestream player. We also encourage you to test out your workflow prior to your event; you can do this with an unpublished (draft) event or create a hidden event and go live prior to embedding it to your website.
There are some limitations to keep in mind when streaming via RTMP with captions. There are components of CEA-608 captions that our player does not fully support:
Multiple language renditions
Foreign language characters
Music or "offscreen" modes
Italics, bolding, and color controls
We’ve also found that the captioning speed can occasionally cause loss of data or jumbled text in broadcasts because the Livestream player does not have a buffer for “not displayed content.” While the required speed of your captions can vary depending on your event, we have found that 100 words per minute (WPM) seems to work best.