Implementation of encapsulating extracted opus payload from RTP packet with ogg container

Question

We have the captured pcap file which includes RTP opus payload per rfc6716, now we can cut off the RTP header and extract the opus payload, we want to encapsulate the payload to ogg opus per spec https://datatracker.ietf.org/doc/html/draft-ietf-codec-oggopus-07 (Ogg Encapsulation for the Opus Audio Codec) and send out, so that VLC can playback the captured opus, we don't want to save to an ogg file then let VLC to playback, we will send the ogg opus out to VLC directly once one packet is encapsulated, anyone who have the referenced implementation of the encapsulation, or 3rd party library I can refer?

Answer 1

The packets can be read using the libpcap library and then encapsulated in Ogg using the libogg library. There is an example program called opusrtp in the opus-tools package that can sniff for Opus RTP packets on the loopback interface using libpcap and write them to Ogg. You would want to do something similar, but change the pcap_open_live() to something like pcap_open_offline() if you want to read from a pcap save file, and write the Ogg pages from libogg to a socket instead of a file. Also define OPUS_PAYLOAD_TYPE to be the RTP payload type you want to look for.