.. _Usecases: Use-cases ========= Open captions driven by REST API calls -------------------------------------- On Linux operating systems Wowza installation ships with OpenJDK that does not include fonts. On Linux you need to manually install `fontmanager` and at least one font `openttf-dejavu` to make open captions work. .. code-block:: bash sudo apt-get install fontconfig sudo apt-get install ttf-dejavu To get the REST API up and running, you need to add the below HTTP provider to your ``VHost.xml`` file: .. code-block:: xml io.ztream.scribe.HttpProviderCaptionApi captions* none You need to add ``ModuleLiveOpenCaptions`` module to your ``Application.xml`` .. code-block:: xml ... ModuleLiveOpenCaptions ModuleLiveOpenCaptions io.ztream.scribe.ModuleLiveOpenCaptions You have to enable transcoder in the application via the Engine Manager UI or directly in the xml: .. code-block:: xml transcoder You also need to set the ``raskenlund.804.license`` application property: .. code-block:: xml raskenlund.804.license W804-1038-xxxx-xxxx-xxxx String Assuming your application is called ``live`` and your incoming stream is called ``myStream``, you can trigger a test caption using curl: .. code-block:: bash curl --location --request POST "http://localhost:1935/captions/v1/applications/live/streams/myStream/caption" \ --header "Content-Type: application/json" --data-raw "{ \"captions\": [ { \"textData\": \"Hello World, this is the captioning module\", \"language\": \"en\" } ], \"delay\": 0 \}" CEA608 captions driven by REST API calls ---------------------------------------- To get the REST API up and running, you need to add the below HTTP provider to your ``VHost.xml`` file: .. code-block:: xml io.ztream.scribe.HttpProviderCaptionApi captions* none You need to add ``ModuleOnTextDataToCEA608`` module to your ``Application.xml`` .. code-block:: xml ModuleOnTextDataToCEA608 ModuleOnTextDataToCEA608 io.ztream.scribe.ModuleOnTextDataToCEA608 You need to set the ``raskenlund.804.license`` application property: .. code-block:: xml raskenlund.804.license W804-1038-xxxx-xxxx-xxxx String You need to configure the below timed text settings in the application: .. code-block:: xml captionLiveIngestType onTextData String captionLiveIngestLanguages eng,nld,nor,hun String WebVTT captions driven by REST API calls ---------------------------------------- Please follow the setup for the CEA608 captions, except that you should not add ``ModuleOnTextDataToCEA608`` to the application, but configure the below timed text property instead: .. code-block:: xml cupertinoLiveCaptionsUseWebVTT true Boolean Speech To Text with AWS Transcribe ---------------------------------- You need to add ``ModuleLiveTranscribe`` module to your ``Application.xml`` .. code-block:: xml ModuleLiveTranscribe ModuleLiveTranscribe io.ztream.scribe.ModuleLiveTranscribe And you must enable transcoder in the application via the Engine Manager UI or directly in the xml. If you do not need video transcoding, you can use the "audioonly" template so that video transcoding is disabled: .. code-block:: xml transcoder audioonly.xml Please make sure that at least one ``Encode``` in your active transcoder profiles have the audio codec set to something other than ``PassThru``. If no audio is being transcoded, the plugin is not able to capture audio frames and send them to AWS, which will time out the transcoding session after 15 seconds without audio data. WebVTT tracks in Adaptive Live Streaming HLS playlists ------------------------------------------------------ When adding WebVTT captions to a live stream, by default Wowza publishes the WebVTT track in each rendition's own ``playlist.m3u8`` but the adaptive playlist that starts with ``ngrp:`` does not contain the text track. To fix this problem the Scribe module contains a custom HTTP Provider that can be configured in the ``VHost.xml`` file and make it responsible for returning the patched playlists. .. code-block:: xml io.ztream.scribe.HttpProviderAbrPlaylistWithSubtitles *master.m3u81 none