Add Messaging, Voice, and Authentication to your apps with Vonage Communications APIs
Visit the Vonage API Developer PortalYou can make audio and video adjustments to published and subscribed streams:
You can toggle audio and video on or off, by calling the otc_publisher_set_publish_audio()
and otc_publisher_set_publish_video() functions, passing in `OTC_FALSE` or `OTC_FALSE` as
the `publish_audio` and `publish_audio` parameters. For example, the following code turns audio off:
otc_publisher_set_publish_audio(publisher, OTC_FALSE);
To set up a voice-only session, instantiate
an otc_publisher_settings struct, call the
otc_publisher_settings_set_video_track()
function, passing in OTC_FALSE as the enabled parameter.
Then use the otc_publisher_new_with_settings() function to create.
For example, the following code creates a publisher for a voice-only session:
otc_publisher_settings publisher_settings = otc_publisher_settings_new();
otc_publisher_settings_set_video_track(publisher_settings, OTC_FALSE);
otc_publisher_callbacks publisher_callbacks = {0};
// Set callbacks for the publisher. Then:
otc_publisher publisher = otc_publisher_new_with_settings(publisher_callbacks, publisher_settings);
The otc_publisher_new() function includes a capturer
parameter. If you set this to NULL, the SDK uses the default
system camera as the source for the published video stream. However, you
can use a custom video capturer for the publisher by defining a
otc_video_capturer_callbacks struct and passing it in
as the capturer parameter of the otc_publisher_new()
function. The otc_video_capturer_callbacks struct includes
function pointers to callback functions that are invoked upon events
related to the publisher video, such as when the video capturer needs a new
video frame.
To see an example, see the Custom Video Capturer sample of the opentok-linux-sdk-samples repo.
You can define a custom audio device, to supply audio to all publishers in the client and to handle the mixed audio stream from all streams the client subscribes to.
A custom audio device is represented by an
otc_audio_device struct. And an
otc_audio_device_callbacks struct includes function pointers
to functions that act as the audio-related callbacks that the OpenTok Linux SDK invokes.
To see an example, see the Custom Audio Device sample in the opentok-linux-sdk-samples repo.
By default, a subscriber is initialized to subscribe to audio and video,
if they are available. You can toggle audio on or off by calling the
otc_subscriber_set_subscribe_to_audio(otc_subscriber *subscriber, otc_bool subscribe_to_audio)
:
// audio off:
otc_subscriber_set_subscribe_to_video(subscriber, OTC_FALSE);
// audio on:
otc_subscriber_set_subscribe_to_video(subscriber, OTC_TRUE);
You can toggle video on or off by calling the
otc_subscriber_set_subscribe_to_video(otc_subscriber *subscriber, otc_bool subscribe_to_video)
:
// video off:
otc_subscriber_set_subscribe_to_video(subscriber, OTC_FALSE);
// video on:
otc_subscriber_set_subscribe_to_video(subscriber, OTC_TRUE);
You can call the otc_stream_has_audio() and otc_stream_has_audio()
member functions of an
otc_stream instance to see if it has audio or video.