What is the best way to stream real-time captions to end-users?

Adding real-time/live captions to your meetings, social media videos or streams is easy with CaptionSync. In this article, we describe the most common options for streaming live captions, and the advantages and disadvantages of each approach.

Provide a StreamText Real-Time Caption Feed

StreamText is a platform that delivers real-time/live captions, and can be accessed by users as a single web page. Streaming the real-time captions this way has the advantage of not requiring any embedding or encoding of the feed into the platform where the video is playing. The real-time captioning text will be displayed on the page as it is transcribed by the captioner, and can be opened in any web browser. The live feed page allows the users to customize the display options, like background color, font type, color and size. More information on how to use the StreamText caption player as a standalone web page is available in our Using StreamText with Live Captioning article.

Another advantage of using StreamText to view live captions is that the feed is often much closer to real-time than when viewing captions via many live video streaming platforms.  This is because StreamText delivers the captions from the caption writer almost character-for-character (sometimes you'll even see the cursor back up while the writer makes a correction), while video streaming platforms often have a delay, due to various technical reasons.  Some scenarios that cause a lag or delay are mentioned below.

Note that using StreamText is an option with all of our real-time captioning services, and is provided on request at no extra charge.

Provide Closed Captions via Your Video Platform

Most webcasting and live video streaming platforms provide a method for streaming a real-time captioning feed within the platform's user interface.  Since these captions can be toggled on or off by individual users, they are referred to as closed captions.  The advantage of this method is that users do not need to go outside of the video platform to turn on or view captions, and no secondary browser is required. There are some additional potential advantages, and disadvantages that vary by platform.  A few examples are provided here.

Blackboard Collaborate

Blackboard Collaborate allows any meeting attendee to be designated as the captioner. There are several advantages of Blackboard Collaborate's real-time closed captioning feature:

• As with StreamText caption feeds, there is very little delay in delivery of the captions.
• The font color and size used for the captions is configurable.
• If you record a Collaborate session where you have a real-time captioner, the captions are saved in the MP4 video file and are also downloadable as a WebVTT file after the session.

Zoom

With Zoom webinars and webcasts you can also designate an attendee as the captioner. Here are some of the benefits of using the Zoom closed captioning feature:

• Attendees who have downloaded one of the Zoom applications to their computer or tablet can adjust the font size of the captions.
• A transcript of the captions can be downloaded as a text file by attendees or hosts at the end of the session. Note that this is a transcript only; caption timing is not included.
• You can stream a Zoom webinar or meeting live on Facebook or YouTube along with captions. More information is available in Zoom's Facebook Live and YouTube Live tutorials.
• Live captions can be recorded along with the video in Zoom, if you are recording the event to the cloud, and have the Save Captions option enabled (under Account Management -> Account Settings -> In Meeting (Advanced)), prior to the beginning of the session. Zoom will then generate a .vtt caption file for you, along with the video.

Unfortunately there are also some disadvantages to the Zoom captioning feature:

• Caption font size cannot be adjusted in the browser version of Zoom (i.e., attendees need to download the Zoom application before the meeting to use the caption features).
• There is often a significant lag in the caption feed when viewed through Zoom, when compared with a StreamText feed.
• When sending the Zoom stream with captions to a live stream, like YouTube or Facebook, there can be a lag in the caption feed in the live stream. 
• The caption window cannot be moved or repositioned on the screen; it always appears in the lower middle part of the screen.
• If a Zoom session is recorded locally (i.e.: your computer), the captions are not saved with the recording.

WebEx

During WebEx meetings, a participant can be designated as the captioner to type in real-time what is spoken by the presenter. Cisco has a detailed tutorial on how to set up closed captioning for WebEx. We can provide live closed captions in a couple of ways:

• Display the captions on the Closed Captions panel, in the meeting window: the host can assign our captioner as the Closed Captionist, and captions will be visible to other meeting participants in real-time.

• Most WebEx products can also accommodate a Media Viewer window for streaming text live from a URL, like from the StreamText platform, which we can employ to deliver captions as well. Captions can be resized and adjusted to preference. To set up this Media Viewer, the host needs to do the following: open Share -> Multimedia; paste the StreamText URL provided by us; finally, open the Media Viewer, on the right-hand side of the WebEx window. Note: the StreamText text feed will show a header and a chat features. To hide them, click Show/Hide Header and Show/Hide Chat, at the bottom of the text window.

Note that, if you'll want captions delivered via StreamText for your WebEx event, you'll need to add that information to the Comments section, at request time. E.g.:

Captions should be delivered in StreamText only. Please provide a StreamText link.

YouTube Live

With YouTube Live streams you can plan in advance for remote real-time captioning. When you schedule a YouTube Live session and configure it for captioning YouTube will provide you with a URL called a "caption ingest URL." You can provide this to us when you schedule a real-time captioning session, and our caption writers can use this to set up their feed. Here are the advantages of YouTube Live captioning:

• Viewers can use the familiar CC button and caption configuration options in the browser-based YouTube player.
• Everything needed by the caption writer can be set up in advance; there is no need to promote the writer after login, and do last-minute setup.
• As with webcasting platforms, no special caption encoder hardware or software is required

Disadvantages of the YouTube Live captioning feature:

• Since there is a delay in YouTube Live video feeds (15-30 seconds) we need to configure a similar delay for the caption writer's feed, otherwise the captions would appear much earlier than the spoken dialog (remember that the caption writer should be listening to the live audio of the event). This requires doing a test a few days before the event to determine the correct delay setting.
• If you're sending the Zoom stream with captions to YouTube Live, there can be a lag in the caption feed in YouTube. Also, captions can only be turned on/off in Zoom. So, if you prefer not to have the captions show in the YouTube video, you can request to have the live captions delivered via StreamText only. 

Provide Open Captions in the Video Stream

One final option is to deliver open captions with your video stream. This requires some setup on your side as the video producer, but it means that all viewers can see captions without any extra effort on their part. Here's how that can be done:

• StreamText provides a lightweight application, called StreamCast, that can be installed on the computer(s) that will be delivering the video (or sharing a screen).  This application receives the caption feed in real-time, and can be positioned anywhere on the video frame.
• As the video is delivered, the captions appear via the StreamText application. In this scenario all viewers will see the captions, thus they are considered open captions.

As an alternative to using StreamText, for YouTube Live and Facebook Live, it's possible to have native captioning, if you use either a hardware or software encoder, such as the ones from EEG (usually rented or purchased from the encoder vendor). The captions are then embedded into the video feed on YouTube or Facebook.

The disadvantages of the options described in this section are common to any use of open captions; captions can't be toggled on/off, and the fonts cannot be changed by individual users. However, for platforms that have not implemented captioning options, this is the only option available.

Which Method is Best?

Which method is best will depend on the video platform that you plan to use and on your viewer audience. Frequent users of captions typically prefer the StreamText URL delivery, for the reasons mentioned above: the fonts can be configured, the delivery is close to real-time, and the position of captions on your screen can be adjusted. On the other hand, infrequent users of captions, or those who are very familiar with your chosen video platform and all of its controls and settings, may appreciate the convenience of having the CC controls all in one user interface.

Remember also that we can provide both a StreamText URL and deliver the captions through the video platform. For platforms like Zoom, which provide a native captioning option that is less than perfect, this is probably your best option. Just let us know when you schedule your session that you want both StreamText and native captions, and we'll take care of the rest.

Additional Notes:

• For more information on how to place Live Captioning requests for your events, check out our article on How to request Live Captioning.