where possible audio devices that disappear are not forgotten until
the user selects another device, this should allow temporarily missing
devices or forgetting to switch on devices before starting WSJT-X to
be handled more cleanly. If all else fails, visiting the Settings
dialog and clicking OK should get things going again. Note that we
still do not have a reliable way of detecting failed audio out
devices, in that case selecting another device and then returning to
the original should work.
Enumerating audio devices is expensive and on Linux may take many
seconds per device. To avoid lengthy blocking behaviour until it is
absolutely necessary, audio devices are not enumerated until one of
the "Settings->Audio" device drop-down lists is opened. Elsewhere when
devices must be discovered the enumeration stops as soon as the
configured device is discovered. A status bar message is posted when
audio devices are being enumerated as a reminder that the UI may block
while this is happening.
The message box warning about unaccounted-for input audio samples now
only triggers when >5 seconds of audio appears to be missing or over
provided. Hopefully this will make the warning less annoying for those
that are using audio sources with high and/or variable latencies. A
status bar message is still posted for any amount of audio input
samples unaccounted for >1/5 second, this message appearing a lot
should be considered as notification that there is a problem with the
audio sub-system, system load is too high, or time synchronization is
stepping the PC clock rather than adjusting the frequency to maintain
monotonic clock ticks.
This is a first cut at this to evaluate buffer size adjustments on
supported platforms. A final version might limit status bar reports to
>1000 dropped frames or similar.
