Put live translated captions over your video stream.

Put captions over your stream in six steps

Most of the work is the first time. After that the link stays in your saved scene.

1. 1

   Send the speaker’s audio to the venue first

   Adding the caption page to your streaming software does not start anything by itself. Before it can show words, the speaker’s audio has to reach the same venue through the desk app or the browser streamer. The caption page only displays the resulting text. It does not listen to your camera or to your streaming software.

   If that is not set up yet, start with the mixer to computer guide, the USB audio interface guide or the browser streaming guide.

   These captions are drawn into the video picture. Viewers cannot switch them off, and they cannot change their language with the video player’s own caption controls. A recording that includes the overlay keeps the captions in the picture. They show one language, the one set as The audience reads on the venue’s Settings tab, and a moderator can change it during the event. If online viewers should choose their own language, give them the listening link as well.

   Speaker

   SpanVoice

   the words

   Streaming computer caption page as a browser source

   Online viewers one language on the picture

2. 2

   Find the captions link

   Each venue has a captions link of the form spanvoice.com/c/ followed by the venue code. It needs no sign-in and does not change, so it is safe to leave in a saved scene.

   You can copy it from the venue’s page in the admin, under For your team, where it is labelled Captions, or from the desk app under Links & QR. Make sure it is the captions link and not the projector or the audience link: they look similar and show different pages.

3. 3

   Add it to OBS or vMix

   These sizes are for a 16:9 picture, 1920 × 1080. For another shape, such as a vertical stream, the layout needs adjusting and this guide does not cover it.

   In OBS

   • Add a Browser source to the scene you stream.
   • Paste the captions link into URL.
   • Set Width to 1920 and Height to 1080.
   • Place it above your camera or slides in the source list, so the band is not hidden behind the picture.

   In vMix

   • Choose Add Input, then Web Browser.
   • Paste the captions link as the address and set the width and height to 1920 and 1080.
   • Show the input with one of the Overlay channels so it sits over the main picture, rather than cutting to it as a scene of its own.

   The page is already transparent, so leave the background alone. The band sits near the bottom of the page by default.

4. 4

   Keep it on air through scene changes

   A source only shows where it has been added, so check this before you go live.

   In OBS, reuse the same caption source in every scene that needs it, using Add Existing, or put it in its own scene and nest that scene inside the others. Then open the source’s properties and check two options:

   • Shutdown source when not visible unloads the page whenever the source is hidden or its scene is not active. Leave it off for captions.
   • Refresh browser when scene becomes active reloads the page each time you switch to the scene, which clears the words on screen. Leave it off too.

   Then switch between your scenes during the test and check the captions carry on.

   In vMix, keep the Overlay channel that holds the captions switched on while you cut between the camera inputs underneath it, and check it stays on across the cuts you use.

5. 5

   Make it look right

   How the band looks is set on the venue’s Caption tab in the admin: the text colour, the colour and opacity of the band behind it, the font size, how many lines show (1 to 6), whether the band sits at the bottom, middle or top, left or centred text, the distance from the edge, the width of the band and how soon the caption clears when nobody is speaking. Press Save and an open overlay follows within a few seconds. The tab has a live preview over a stand-in backdrop. Two lines at the bottom is the default and suits most streams; use the top if your picture already has a lower-third graphic.

   For a change on one computer or one source only, add settings to the end of the link, for example ?lines=1&size=36&pos=bottom&margin=8. Anything in the link overrides the Caption tab for that source. If your software keeps a copy of the page, refresh the source after saving on the Caption tab.

6. 6

   Test the finished stream, including the timing

   With the scene showing in your software’s preview, start a short event from the desk app, or play the test file, and speak a few sentences. The band should appear with the words, and hide again after a quiet pause. With no event running the band is hidden, so an empty preview is normal.

   Then check what viewers will see:

   • Watch the finished stream on another device, not only your own preview.
   • Compare each spoken sentence with the moment its words arrive. The words come a moment after the speaker, because the speech has to be heard and translated first.
   • If you also give viewers the listening link, remember the video and the phone follow different routes, so they will not line up. Do not rely on them matching.
   • Test again whenever you change the video or audio path.

   To check the look without a camera, add img= and the address of a still picture to the link. It only supplies a backdrop; no sample words appear, so you still need a running event to see text. Remove it before going live.

   The band hides itself after 5 seconds of quiet by default; the venue’s Caption tab can change that. Add idle=0 to the link to keep the latest words on screen, or a number of seconds for a different time. It does not create words when nothing has been said.