Production machines rarely have ffmpeg/sox, and the LTC reader only needs
"device N → s16le stdout". This ~200-line Swift CLI (compiles with the
Xcode CLT already on the target: swiftc -O -o tools/ltc-capture
tools/ltc-capture.swift) enumerates input devices (--list), pins an
AVAudioEngine tap to one picked by name substring (--device), and streams
interleaved s16le at the device's own rate/channel count, printing the
matching --sr/--channels reader flags to stderr.
Verified by a real loopback on BlackHole 64ch: synthesized LTC played into
the device, captured back (channel 2 of 64 @ 44.1 kHz), decoded to
running/stopped on live tiles with zero drift over 14 s.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
