Dynamic creation of media transports

[bennylp]

This ticket implements ticket #539.

See the spec in ReleaseNotes-2.0

[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. :)

[bennylp]

Work is still needed to make the transport creation asynchronous. Reopening the ticket.

[bennylp]

(In [3506]) Re #1185: requesting call hold did not set video direction to sendonly

[bennylp]

(In [3520]) Re #1185: fixed ICE media transport to work with video in pjsua-lib

[nanang]

In r3560:

• Fixed bug media transport is not closed after call disconnected.
• Fixed handling remote re-offer, media transport will be created/disabled when media is added/removed/deactivated.