Integrating a VIDEO RBT Service

I am currently working on that involves implementing video Ring Back Tone (RBT) using FreeSWITCH. I have encountered a challenge during the implementation process and would greatly appreciate your assistance in resolving it.

To provide some context, here is an overview of the project requirements:

  1. Caller A initiates a call to Caller B (regular audio call).
  2. During the call, Caller A should be able to see a video display while hearing audio.

Currently, I have been able to achieve the desired functionality using FreeSWITCH. When Caller A initiates a video call to Caller B, the video is displayed on Caller A’s end, and audio is transmitted successfully. However, when making a standard audio call, only audio is being played without any video.

For testing purposes, I have been using PortSIP on Android to initiate the calls and observe the results. Despite successful implementation of video RBT during video calls, I am facing difficulty in enabling audio RBT during regular audio calls.

I tried adding every header i could possibly find to tell PortSIP that a video is about to play, but nothing is working:

<extension name="playvideo">
        <condition field="destination_number" expression="1122">
                <action application="set" data="call_video_support=true"/>
                <action application="set" data="sip_h_Alert-Info=info=alert-external;delay=0"/>
                <action application="set" data="sip_h_Content-Disposition=render"/>
                <action application="set" data="video_media_flow=true"/>
                <action application="set" data="video_imageattr_send=true"/>
                <action application="set" data="video_imageattr_recv=true"/>
                <action application="set" data="video_textattr_send=true"/>
                <action application="set" data="video_textattr_recv=true"/>
                <action application="answer" />
                <action application="set" data="playback_early_media=true"/>
                <action application="set" data="call_video_support=true"/>
                <action application="set" data="sip_h_Alert-Info=info=alert-external;delay=0"/>
                <action application="playback" data="/var/lib/freeswitch/videos/video.mp4"/>
        </condition>
</extension>

Try with something like https://tryit.jssip.net and see if you are getting the same or different results as PortSIP on Android.