[FFmpeg-user] Does ffmpeg accept input directly from serial ports?

[Zac Harvey]

I will be running ffmpeg on a Linux (Debian) machine that will be connected
to a serial device (via GPIO pins), which is the source of both my audio
and video bitstreams. Can ffmpeg somehow accept a serial device (perhaps a
UART or SPI connection) as input, or perhaps works directly with a
compatible device driver?

If not, I will have to write some custom software that reads incoming
audio/video data from the serial port and writes it to a file.  Then,
configure ffmpeg to read from that file. In that case, here's my question:
can ffmpeg get read access to a file that my software is simultaneously
writing audio or video data to? What would experienced ffmpeg users do?
Thanks in advance.