I have the exact same problem on Zoiper Android. I have the following settings:
TLS and SRTP enabled and required.
Zoiper -> Video -> Always offer video: yes
Accounts -> Podictive -> Video Codec Settings, only VP8 enabled and on top
Yet, if I dial to Zoiper I see on the incoming SIP-request no video codecs listed. Calling to Zoiper with Video also does not work.
Example SIP request:
v=0
o=- 214884055 214884055 IN IP4 136.144.156.242
s=Asterisk
c=IN IP4 136.144.156.242
t=0 0
m=audio 14156 RTP/SAVP 9 8 3 18 101
a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:CVWxHxMiwatKWQFm30isSqKUQPnHAXDPrMT01IZh
a=rtpmap:9 G722/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:3 GSM/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16
a=ptime:20
a=maxptime:150
a=sendrecv