gstrtp.rtpheader_extension.RTPHeaderExtension.setId must have been called with a valid extension id that is contained in these caps.
The only current known caps format is based on the SDP standard as produced by gstsdp.sdpmedia.SDPMedia.attributesToCaps.
writable #GstCaps to modify
whether the configured attributes on ext can successfully be set on caps
gstrtp.rtpheader_extension.RTPHeaderExtension.setId must have been called with a valid extension id that is contained in these caps.
The only current known caps format is based on the SDP standard as produced by gstsdp.sdpmedia.SDPMedia.attributesToCaps.