pcapsipdump synchronized two channel audio

i use pcapsipdump to create individual pcap files of specific voip calls. each pcap file is a two channel pcap file with each talker in one of the channels. use RTP stream analysis and the "save payload" button wireshark is able to save the audio in these files to raw or au files in one or both directions and with au files is able to mix the audio into a single channel. The issue is that when doing it this way the channels are not in sync with each other and the conversations drifts between the two channels such that after a few minutes of audio the speakers' conversation can be out by 10 or more seconds between the channels.

However, If i use the VoIP call analyzer and play the file back through the sound card the two channels playback in perfect sync. if this dialog has a "save audio" button then a synchronized one or two channel recording file could be created (either is acceptible) directly.

As it stands now the audio had to be replayed back into a recording system to produce the synchronized audio, undesirable because this is done in real time, so a 1 hour recording takes 1 hour to replay and synchronize.

I have looked into at least half a dozen rtp pcap tools to do the same but have yet to find one that can do this correctly (the all produced individual audio files)

Please let me know if a "save audio" feature could be added to the player option in VoIP Calls. Thanks, Les