# Closed Captioning with multiple bitrates (smil) not working

**URL:** <https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795>\
**Category:** Wowza Streaming Engine\
**Tags:** closed-captioning\
**Created:** [November 24, 2025, 4:25pm UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795 "2025-11-24T16:25:32Z")\
**Posts on this page:** 9\
**Page:** 1

<div class="post-metadata">

**Author:** ![Bernhard\_Schmidt](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/bernhard_schmidt/32/687_2.png) [@Bernhard\_Schmidt](https://community.wowza.com/u/Bernhard_Schmidt)\
**Post date:** [November 24, 2025, 4:25pm UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/1 "2025-11-24T16:25:32Z")

</div>

Hi,

I’d like to use the speechToText module as described here: [Convert speech to text to generate live stream captions with Azure AI Speech Services | Wowza Docs & APIs](https://www.wowza.com/docs/convert-speech-to-text-to-generate-live-stream-captions-with-azure-ai-speech-services)

So far it works fine for single streams, but I’d like to transcode in multiple bitrates.  
I have the transcoder set to transcode the stream “wowzatest” into wowzatest\_720p and wowzatest\_360p streams.

When I access the HLS streams via “/wowzatest\_720p/playlist.m3u8” everything works fine and I see the subtitles.

But I need bitrate switching, so I created this SMIL, according to the documentation: [Convert speech to text to generate live stream captions with Azure AI Speech Services | Wowza Docs & APIs](https://www.wowza.com/docs/convert-speech-to-text-to-generate-live-stream-captions-with-azure-ai-speech-services#install-the-module)

```auto
<?xml version="1.0" encoding="UTF-8"?>
<smil title="">
  <body>
    <switch>
      <video height="720" src="wowzatest_720p" width="1280">
        <param name="videoBitrate" value="3500000" valuetype="data"></param>
        <param name="audioBitrate" value="128000" valuetype="data"></param>
        <param name="cupertinoTag.SUBTITLES" value="subs" valuetype="data"/>
      </video>
      <video height="360" src="wowzatest_360p" width="640">
        <param name="videoBitrate" value="1300000" valuetype="data"></param>
        <param name="audioBitrate" value="128000" valuetype="data"></param>
        <param name="cupertinoTag.SUBTITLES" value="subs" valuetype="data"/>
      </video>
      <textstream src="wowzatest_720p" system-language="ger">
        <param name="iswowzacaptionstream" value="true" valuetype="data"/>
        <param name="cupertinoTag.TYPE" value="SUBTITLES" valuetype="data"/>
        <param name="cupertinoTag.GROUP-ID" value="subs" valuetype="data"/>
        <param name="cupertinoTag.DEFAULT" value="YES" valuetype="data"/>
        <param name="cupertinoTag.FORCED" value="NO" valuetype="data"/>
      </textstream>
    </switch>
  </body>
</smil>

```

Unfortunately, when accessing the stream with “/smil:wowzatestmbr.smil/playlist.m3u8”, both streams don’t show subtitles (no CC icon).

Interestingly, the **wowzatestmbr.smil/playlist.m3u8** contains this information: (doesn’t work)

```auto
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA:TYPE=CLOSED-CAPTIONS,GROUP-ID="subs",NAME="Deutsch",FORCED=NO,AUTOSELECT=YES,DEFAULT=YES,LANGUAGE="ger"
#EXT-X-STREAM-INF:BANDWIDTH=3628000,RESOLUTION=1280x720,CLOSED-CAPTIONS="cc"
chunklist_w857691546_b3628000.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=1428000,RESOLUTION=640x360,CLOSED-CAPTIONS="cc"
chunklist_w857691546_b1428000.m3u8

```

Whereas when accessing the **wowzatest\_720p/playlist.m3u8** directly, it shows this: (works)

```auto
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subs",NAME="Deutsch",FORCED=NO,AUTOSELECT=YES,URI="subtitlelist_lde_w663707475.m3u8",LANGUAGE="de"
#EXT-X-STREAM-INF:BANDWIDTH=2448140,CODECS="avc1.4d401f,mp4a.40.2",RESOLUTION=1280x720,SUBTITLES="subs"
chunklist_w663707475.m3u8

```

Any ideas?

---

<div class="post-metadata">

**Author:** ![Karel\_Boek](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/karel_boek/32/454_2.png) [@Karel\_Boek](https://community.wowza.com/u/Karel_Boek)\
**Post date:** [November 25, 2025, 2:26pm UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/2 "2025-11-25T14:26:19Z")

</div>

Hi, if it’s of interest: I have a module that does this - PM me or email [info@ztream.io](mailto:info@ztream.io)

---

<div class="post-metadata">

**Author:** ![Bernhard\_Schmidt](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/bernhard_schmidt/32/687_2.png) [@Bernhard\_Schmidt](https://community.wowza.com/u/Bernhard_Schmidt)\
**Post date:** [November 25, 2025, 2:45pm UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/3 "2025-11-25T14:45:36Z")

</div>

So it’s not possible with standard WSE? That’d be strange…  
I sent you a mail 🙂

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<div class="post-metadata">

**Author:** ![Vihari\_Kumar](https://avatars.discourse-cdn.com/v4/letter/v/87869e/32.png) [@Vihari\_Kumar](https://community.wowza.com/u/Vihari_Kumar)\
**Post date:** [December 1, 2025, 1:22am UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/4 "2025-12-01T01:22:09Z")

</div>

Hello @Bernhard_Schmidt

Thanks for reaching out!

We’ve already addressed your query regarding “**Closed Captioning with multiple bitrates (smil) not working**” in the support ticket you submitted - 36112165271.

Please refer to the detailed response provided in the ticket for the solution. If you have any further questions after reviewing it, please feel free to open a new support ticket, and we’ll be happy to assist you further.

Regards,  
Vihari

---

<div class="post-metadata">

**Author:** ![Scott\_Kellicker2](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/scott_kellicker2/32/1337_2.png) [@Scott\_Kellicker2](https://community.wowza.com/u/Scott_Kellicker2)\
**Post date:** [December 1, 2025, 2:08pm UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/5 "2025-12-01T14:08:36Z")

</div>

Hey Vihari! Can you share the answer so rest of community can benefit?

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<div class="post-metadata">

**Author:** ![Scott\_Kellicker2](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/scott_kellicker2/32/1337_2.png) [@Scott\_Kellicker2](https://community.wowza.com/u/Scott_Kellicker2)\
**Post date:** [December 5, 2025, 3:16pm UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/6 "2025-12-05T15:16:15Z")

</div>

@Vihari_Kumar Can you follow-up. Does this work if it is configured properly? If so, what is the trick?

Or does this not currently work in WSE?

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<div class="post-metadata">

**Author:** ![Dorota\_Szafer-Kwasik](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/dorota_szafer-kwasik/32/1150_2.png) [@Dorota\_Szafer-Kwasik](https://community.wowza.com/u/Dorota_Szafer-Kwasik)\
**Post date:** [December 14, 2025, 8:32am UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/7 "2025-12-14T08:32:35Z")

</div>

.. doesn’t want to share his “secret” knowledge .. 🙂

---

<div class="post-metadata">

**Author:** ![Drumil\_Desai](https://avatars.discourse-cdn.com/v4/letter/d/c67d28/32.png) [@Drumil\_Desai](https://community.wowza.com/u/Drumil_Desai)\
**Post date:** [December 15, 2025, 3:06am UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/8 "2025-12-15T03:06:55Z")

</div>

Hello @Scott_Kellicker2

We apologize for the delay in the response as we were working with Bernhard on troubleshooting the issue. We found that a property named **“cupertinoLiveCaptionsUseWebVTT”** was not enabled in the Application.xml which was causing the captions to not be viewed on playback. As mentioned in the [article](https://www.wowza.com/docs/convert-speech-to-text-to-generate-live-stream-captions-with-azure-ai-speech-services#test-playback8), the renditions include WebVTT captions.

Bernard confirmed that enabling the property resolved the issue and the workflow is working as expected.

We will be updating the article to mention the property **“cupertinoLiveCaptionsUseWebVTT”** needs to be enabled.

Best Regards,  
**Drumil Desai​**

_Technical Support Engineer_

**Wowza** | The **solution** you start with, the **partner** you scale with.

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<div class="post-metadata">

**Author:** ![Scott\_Kellicker2](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/scott_kellicker2/32/1337_2.png) [@Scott\_Kellicker2](https://community.wowza.com/u/Scott_Kellicker2)\
**Post date:** [December 17, 2025, 1:23pm UTC](https://community.wowza.com/t/closed-captioning-with-multiple-bitrates-smil-not-working/102795/9 "2025-12-17T13:23:44Z")

</div>

Thanks for the update!