A first real transmission settled one question and raised a better one.
With the receive stream open and six seconds of transmit, the radio sent
282 frames of receive audio and NOTHING else: no chrono, no transmit
audio. So the chrono the documentation describes is not offered to a
client that merely happens to be connected while the operator keys the
microphone, and waiting for it to appear is waiting for nothing.
The reading that fits is that the radio asks for audio when the
transmission is the CLIENT'S and takes the microphone when it is the
operator's — which makes the experiment obvious. Key it from here, push a
1 kHz tone, and watch. Chrono frames appearing gives their size and
cadence by measurement instead of by guesswork; no chrono but a tone on
the meter is just as useful, because then the pacing is optional and the
voice keyer can push frames at the rate the stream already runs at.
A tone rather than silence so the answer shows on the power meter and not
only in the log.
It transmits, so: an explicit button inside a warning box, five seconds,
capped at ten, and every path out unkeys — including the panic that has
not happened yet and a socket that dies mid-tone. A transmitter left keyed
by a defect is the one fault here that would reach somebody else's band.
Writes are now serialised too. send() held the lock only long enough to
read the connection, which was enough while every command came from the
poll loop; a stream of audio frames from a second goroutine is not, and
gorilla panics on a concurrent write rather than failing quietly.
A SunSDR already carries its receive audio on the same WebSocket as its
commands, so a virtual audio cable and a second sound card are two pieces
of plumbing an operator installs for no reason. This is the receive half:
what the QSO recorder and the CW decoder need.
The reader now looks at the frame type. It used to ignore it and split
every frame on ';' -- harmless only for as long as no stream was ever
opened, since audio bytes would otherwise have been handed to the command
parser a hundred times a second.
NOTHING HERE IS CONFIRMED ON A RADIO. The header layout comes from the
TCI documentation, and the stream-type numbers are exactly the sort of
detail a document gets right and a memory of it does not -- so the first
forty frames of a session are logged verbatim, and a test bench in
Preferences > Audio reports the sample rate the radio chose, the frames
arriving and the peak level of the last second. 'The stream is open' and
'audio is arriving' are different claims and only the second is worth
anything to whoever tries this first.
Transmit (the voice keyer) is the other half and is deliberately absent:
it has to answer the radio's chrono packets at the right pace, and that
is worth doing once the format is settled on real hardware.
rouggy