Video issues with FreePBX 14 + Asterisk 13

FreePBX 14 + Asterisk 13 - i have added the cisco-usecallmanager-patch have soft keys working - more or less everything i need is there including conference - hold - forward - speed dials - etc etc. I have limited the extensions to “alaw&gsm&g722&g729&h264” which they all do support (i have also tried with no codec restrictions) - i have h264 in the chan_sip setup (not using pjsip) - the video is working on the handsets as i can “self view" fine - i am using bria 5 soft phone to test this with.

I can start a video call on the CP-8941 to Bria 5 - and both video and audio work fine - when i call the CP-8941 from Bria 5 there is no video and i see the following in the console. (98 is Bria and 105 is CP-8941)

  == Spawn extension (from-internal, 227, 1) exited non-zero on 'SIP/227-00000042'
    -- SIP/227-00000042 Internal Gosub(autoanswer,s,1(Ring Answer,<uri>;answer-after=0)) complete GOSUB_RETVAL=
    -- Called SIP/227
    -- Connected line update to SIP/222-00000040 prevented.
    -- Connected line update to SIP/222-00000040 prevented.
    -- SIP/227-00000042 is ringing
    -- Connected line update to SIP/222-00000040 prevented.
    -- SIP/227-00000042 answered SIP/222-00000040
    -- <SIP/227-00000042> Playing 'beep.ulaw' (language 'en_GB')
       > 0x7f664c03fbb0 -- Probation passed - setting RTP source address to 192.168.0.105:10050
    -- Channel SIP/227-00000042 joined 'simple_bridge' basic-bridge <0bc663f3-1d1e-4393-a07d-f22c1f29caa5>
    -- Channel SIP/222-00000040 joined 'simple_bridge' basic-bridge <0bc663f3-1d1e-4393-a07d-f22c1f29caa5>
       > 0x7f65d471e6c0 -- Probation passed - setting RTP source address to 192.168.0.98:13262
       > 0x7f65d47210c0 -- Probation passed - setting RTP source address to 192.168.0.98:10684
       > 0x7f664c042d20 -- Probation passed - setting RTP source address to 192.168.0.105:10052
[2017-08-31 11:17:36] WARNING[14713][C-0000001f]: res_rtp_asterisk.c:4960 ast_rtp_read: RTP Read too short

I am currently on SIP8941_8945.9-3-4-17 firmware on the handsets - i previously took it to SIP894x.9-4-2SR3-1 - which crashed the handsets soon after i saw the “ RTP Read too short message” on the console. (identical to this post http://eng.sysadmins.ru/post11804369.html)

If anyone has any pointers to help me chase this down - i have ssh access to handsets - counterpath are involved with troubleshooting it from the Bria 5 side of things - the CP-8941 is EOL from cisco and does not seem to be to popular so not getting too much info from the community.

Scratch all that… Bria is capable of sending HD - the CP-8941 handset cannot handle it… amazing how much info one can get from the SSH debug session - but the guaranteed hangs with firmware 9.4.x mean i will stay at 9.3.x on these handsets.