Video support in PJSUA-LIB

[bennylp]

(In [3457]) Modifications in PJSUA-LIB to support multiple media streams (multiple audio and/or video) and dynamic creation of media transports. This closed #1185 and closed #1201.

1185: Dynamic creation of media transports
============================================
Done:

• media transports are created on demand now

Todo:

• media transport creation is still blocking

1201: Video support in PJSUA-LIB
===================================
Done:

• call now supports N media (N audio and M video)
• number of audio/video streams is configurable per acc
• extra audio stream info in pjsua_call_info to support multiple audio streams

in one call

• video subsys and ffmpeg initialization in PJSUA-LIB
• ability to offer and create video SDP answer
• "dq" for more than 1 audio streams
• introducing pjsua_state and pjsua_get_state()

API change:

• on_stream_created() and on_stream_destroyed() callbacks: changed session to

stream

Todo:

• many others features are disabled, just search for DISABLED_FOR_TICKET_1185

macro (these have also been added to ticket #1193 (Issues & Todos)). Notable
missing features are:

• creation of duplicate SDP m= lines for optional SRTP
• mm.. that's it?

• whole lot of testings

pjsua:
===============

• Added --extra-audio and --video options. Specify these more than once and

each time an extra audio/video streams will be added. :)

[nanang]

(In [3463]) Re #1201:

• Initial version of video stream integration into pjsua-lib.
• Replaced audio info array in pjsua_call_info with media info array.
• Added video media info into call dump.
• Fixed assertion caused by pjsua_set_state(NULL) logging after pjlib shutdown.

[bennylp]

(In [3465]) Re #1201: replace union media stream in pjsua_call_media with struct, to avoid the conf_slot corrupting the video capturer value

[nanang]

(In [3471]) Re #1201: Added pjsua API for video devices and codecs management.

[nanang]

(In [3476]) Re #1201: Fixed bad definition of pjsua_vid_set/get_setting() (caused compilation error on GCC).

[nanang]

(In [3508]) Re #1201: Fixed crash when remote initiate call hold with SDP media connection address "0.0.0.0".

[nanang]

(In [3512]) Re #1201:

• fix bug responding 488 after receiving re-INVITE for doublehold
• updated pjsua_media.c to skip instantiating video devs when call hold by local.

[bennylp]

(In [3518]) Re #1201: fixed sending 488 when receiving double hold

[nanang]

(In [3521]) Re #1201: Added SDP c= line in session level copied from the c=line of the first media, for compatibility purpose.

[bennylp]

(In [3531]) Re #1201: re-enable printing of ICE and SRTP specific info in call statistic output