The isinf function returns -1 for negative infinity on glibc, but
the standard guarantees no such behavior (e.g. in C++ it always
returns a bool, on musl libc it's a macro that expands to a bool
expression), saying just that it returns a non-zero value.
This was added in pulseaudio around 15 years ago, and was never
fixed; pipewire then got the code from it. However, we can portably
check against -INFINITY instead (from math.h, already included).
Ref 045c1d6
libacp is a port and wrapper around the pulseaudio card profile code.
It uses a set of templates for construct a card profile and mixer port
settings. It also has support for UCM when available for the hardware.