Debug Mode for example client mp4 ? Enhancement

[jlpoolen]

I'm sorry, I'm just not going to have time to get up to speed on rust, but I think I can offer something of value if my attempts fail and there is some instruction on how to provide debugging information. I just updated Issue #28 and since I was referencing the online help, I did not see anything that suggest how to provide debugging information. It there is a way, it might be in the instructions and/or active help.

ares /usr/local/src/retina # date; cargo run --example client mp4 --url rtsp://192.168.1.12:5000   /tmp/retina_out.mp4;date;
Fri Feb  4 19:40:48 PST 2022
warning: field is never read: `sdp`
   --> src/client/mod.rs:189:5
    |
189 |     sdp: SessionDescription,
    |     ^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default

warning: field is never read: `name`
  --> src/codec/aac.rs:53:5
   |
53 |     name: &'static str,
   |     ^^^^^^^^^^^^^^^^^^

warning: field is never read: `loss_since_mark`
   --> src/codec/aac.rs:478:5
    |
478 |     loss_since_mark: bool,
    |     ^^^^^^^^^^^^^^^^^^^^^

warning: field is never read: `established`
   --> src/lib.rs:215:5
    |
215 |     established: std::time::Instant,
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

warning: `retina` (lib) generated 4 warnings
    Finished dev [unoptimized + debuginfo] target(s) in 0.07s
     Running `target/debug/examples/client mp4 --url 'rtsp://192.168.1.12:5000' /tmp/retina_out.mp4`
E20220204 19:40:48.849 main client] Fatal: Unable to connect to RTSP server: Connection refused (os error 111)
Fri Feb  4 19:40:48 PST 2022
ares /usr/local/src/retina # ls -la /tmp/ret*
ls: cannot access '/tmp/ret*': No such file or directory
ares /usr/local/src/retina #  # no partial file,  Issue #32 ?