Do not deduce audio properties from command-line parameters but from
the actual format that is being to sent.
Until now, the properties like ch_count and sample rate was deduced from
command-line parameters (ch_count from `-a channels=` and sample rate from
`-A xxx:sample_rate`). However, this is a bit fragile - the source may not
respect the `-a` parameters and also the `-A sample_rate` doesn't need
to be set, like in the following case:
```
uv -x rtsp -A A-law -a sample_r=8000 -s testcard
```
Here the capture sample_rate is set to 8000 but not parsed from parameters
(it must have been in `-A`). So SDP parameeters for RTSP was set
incorrectly (48000).
renamed to rtsp_type_audio and rtsp_type_video
Although not causing probles by now, the name itself (which is as a
part of unscoped struct global) is very common so it could have caused
conflicts in future.
print the SDP without need for connected client
Previously, the generated SDP was printed just as a client connects
because the sdpLines() member is called just after that (with appropriate
IP version).
When destroying the state, ServerMediaSubsession::deleteStream callbacks
are called but we are already deconfiguring so do not send messages to
change destination (eg. audio is already destroyed so the message wont
be delivered causing warnings like:
```
Receiver audio.sender does not exist.
Receiver audio.sender does not exist.
Warning: Message queue not empty!
```
Currently this is just a dirty fix, rtsp_serv::watch would be better to
pass.
When the client doesn't call TEARDOWN (like ffplay doesn't),
the stream could not have been played until the timeout (given by
`reclamationTestSeconds`). After that (or when TEARDOWN was called),
`BasicRTSPOnlySubsession::deleteStream()` is called allowing the new
stream.
After this change, the stream can be redirected withot explicit TEARDOWN
or timeout.
For audio codecs, we respect its native capitalization of letters, eg.
AAC, speex. So do it also for Opus. This should not affect existing
applications since the Opus name is parsed case-insensitively.
Only exception is SDP (rtpmap) where is usually used lower-case (at
least in rfc7587).
using bound checking variants
Remained last one instance in utils/text.c, that does the checking by
itself and vsnprintf compat using vsprintf, that is not used, anyways.
