Capture rtp host and port from sdp

[Marc-i2x]

This allows the creation of RTP streams with ffmpeg instead of pcap replay. Snippet from UAC scenario:

  <!-- Play RTP stream through ffmpeg   -->
  <nop>
    <action>
      <exec command="ffmpeg -nostats -loglevel 0 -re -i ~/arbitrary.wav -ar 8000 -acodec pcm_mulaw -f rtp rtp://[last_media_ip]:[last_media_port] >>/dev/null" />
    </action>
  </nop>

[wdoekes]

Hi!

Could you rebase this against master and fix so all tests succeed?

Thanks!

[Marc-i2x]

Could you rebase this against master and fix so all tests succeed?

done. I also made find_in_sdp availability independent of compile flags as the PR will allow sending RTP without pcap support.

[wdoekes]

Interesting idea. I'm a bit reluctant to allow overloading the last_HEADER for this purpose though, as media_ip is not a header (obviously).

It's already a jungle of small little hacks here and there.

How about you make it [lastsdp_media_ip] instead. Add the appropriate docs, so people will actually know the feature exists. And indent with 4 spaces (*). Thanks! :)

(*) See: 7e62db1 and
astyle --indent=spaces=4 --unpad-paren --pad-header --pad-comma --pad-oper ...

[rkday]

Or perhaps peer_media_ip, peer_media_port, by analogy with peer_tag_param?

[rkday]

I wonder if it might be slightly better to always call extract_rtp_remote_addr (at line 2820 or so) instead of guarding it with #ifdef RTP_STREAM, and store the host/port off as member variables on the call object, then just use those (in the same way we use the pre-stored peer_tag when handling E_Message_Peer_Tag_Param). That would guarantee that the host/port would be retrieved consistently whether you used built-in RTP streaming or this method.

[Marc-i2x]

Interesting idea. I'm a bit reluctant to allow overloading the last_HEADER for this purpose though, as media_ip is not a header (obviously).

It's already a jungle of small little hacks here and there.

How about you make it [lastsdp_media_ip] instead.

Could you guide me how to achieve this? Where would I have to add the respective code?

Add the appropriate docs, so people will actually know the feature exists.

Will do once I find some free time

And indent with 4 spaces (*). Thanks! :)

Will do