hello, I have something like this:

function_that_use_ffmpeg | while read line; do ... done

It appears that ffmpeg access the tty directly, for example when asking for
interactive input

in this case, the process got suspended with the message suspended (tty
output)
if I pipe it to cat, it is not suspended
If it convert the second part of the pipe to a subshell:

function_that_use_ffmpeg | (while read line; do ... done)

it is not suspended.
If I disable job control with setopt nomonitor, it is not suspended.
I wonder why the subshell changes the behaviour, and if I can solve this
problem without using this hack and without disabling job control

thanks

Pier Paolo Grassi