This is a puredata external using the velipso/sndfilter dsp library. Currently only the reverb algorithm is available via the [sndfilter.reverb~] pd object.

Note: Currently the instructions are only for linux.

Todos

• [ ] Build for windows (mac? anyone?)
• [ ] add compressor module
• add biquad filters? perhaps not needed as pd already has the [biquad~] object.

Build

rm -rf build
meson setup build
meson compile -C build

# Building in release mode
meson configure build -Dbuildtype=release
# some extra args as seen in reference Makefile
meson configure build -Dc_args='-funroll-loops -fomit-frame-pointer -O6'

allow-shlib-undefined stupidity & spotting ACTUAL linker error

Symbols such as pd_new, gensym etc are provided by puredata. However, when this library (external in pd lingo) is compiled, these symbols are not present, but they will be provided by the puredata executable itself on loadtime/runtime.

For this to work, and not get any linke errors, we need the allow-shlib-undefined linker flag. BUT the problem now is that we loose any other compiler warning about any actual linker errors (if, say, we also are using some other utility library that we forgot to link to!).

The following snippet provides a way to spot such errors by

• disabling the allow-shlib-undefined linker flag (meson built in option b_lundef handles this)
• linking against libpd (you have to build it yourself, instructions below)
• compile as usually
• if you get linker errors now, these should be resolved!

# building libpd
git clone https://github.com/libpd/libpd.git --recurse-submodules
(cd libpd; mkdir build; cd build; cmake ..; cmake --build .)

LIBPD_LIB_DIR=$(realpath ./libpd/build)

meson configure build -Db_lundef=true
meson configure build -Dc_link_args="-L${LIBPD_LIB_DIR} -lpd"
meson compile -C build # if that fails, then there's an actual linker error

# revert: just ignoring undefined symbol linker errors
meson configure build -Db_lundef=false
meson configure build -Dc_link_args=''
meson compile -C build # that won't mention any linker errors, like ever! :(

# check
meson configure build | grep b_lundef

read more here:

• how-to-smartly-detect-undefined-symbols-when-linking-a-plugin
• what-exactly-does-rdynamic-do-and-when-exactly-is-it-needed

Install

To make this available to puredata, the compiled object & the help file need to be placed in puredata’s search directory. See more here.

mkdir -p ~/.local/lib/pd/extra/sndfilter/

cp ./build/sndfilter.pd_linux ~/.local/lib/pd/extra/sndfilter/
cp ./help/* ~/.local/lib/pd/extra/sndfilter/

# to uninstall
rm -rf ~/.local/lib/pd/extra/sndfilter/

Usage

puredata ./help/sndfilter.reverb~-help.pd