• Success Criterion 1.2.4
  • Conformance level AA

Hybrid Event Where Only the Room, Not the Stream, Is Captioned

1.2.4 — Captions (Live)

Scenario

Setting

A ride-hailing app's trip booking screen

What’s wrong

Hybrid events where only the in-room feed is captioned, not the web stream.

Example 

<div class="driver-townhall-stream">
  <!-- CART captioner's output only displays on the in-room screen; the
       web stream never receives the caption feed -->
  <video src="live://driver-townhall-webfeed" autoplay controls></video>
</div>

Why it matters

A deaf driver watching the safety town hall from home sees the exact same video as everyone in the room, but without the captions the in-room audience can see on the wall screen.

How to test

For hybrid events, check the web stream specifically (not just the in-room screen): if only in-room viewers get captions, the web stream fails.

How to fix

For hybrid events, route the captioner's output to both the room screen and the streaming encoder, since they're two separate audiences.

<div class="driver-townhall-stream">
  <video src="live://driver-townhall-webfeed" autoplay controls>
    <track kind="captions" src="live://driver-townhall-cart-feed" srclang="en" label="Live captions">
  </video>
</div>
<!-- The same CART captioner's text output is now routed into the
     streaming encoder's caption channel, not just the room display -->

Outcome

A deaf driver watching remotely reads the same captions the in-room audience sees on the wall screen.

Who is affected

Deaf and hard-of-hearing remote viewers of a hybrid event lose captioning entirely, even though it exists for people physically in the room.

Learn more

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