MIDI playback support with custom SoundFonts

.pre-commit-config.yaml

@@ -36,4 +36,4 @@ repos:
     hooks:
     -   id: mypy
         args: ["--pretty"]
-        additional_dependencies: ["pygobject-stubs", "types-PyYAML", "types-Markdown", "types-requests", "types-pycurl", "types-chardet", "pytest-stub", "types-orjson", "pathvalidate", "requirements-parser", "icoextract", "fvs", "patool", "git+https://gitlab.com/TheEvilSkeleton/vkbasalt-cli.git@main"]
+        additional_dependencies: ["pygobject-stubs", "types-PyYAML", "types-Markdown", "types-requests", "types-pycurl", "types-chardet", "pytest-stub", "types-orjson", "pathvalidate", "requirements-parser", "icoextract", "fvs", "patool", "pyfluidsynth", "git+https://gitlab.com/TheEvilSkeleton/vkbasalt-cli.git@main"]

bottles/backend/managers/manager.py

@@ -725,6 +725,7 @@ def get_programs(self, config: BottleConfig) -> list[dict]:
                     "pre_script": _program.get("pre_script"),
                     "post_script": _program.get("post_script"),
                     "folder": _program.get("folder", program_folder),
+                    "midi_soundfont": _program.get("midi_soundfont"),
                     "dxvk": _program.get("dxvk"),
                     "vkd3d": _program.get("vkd3d"),
                     "dxvk_nvapi": _program.get("dxvk_nvapi"),

bottles/backend/utils/meson.build

@@ -6,6 +6,7 @@ bottles_sources = [
   'display.py',
   'gpu.py',
   'manager.py',
+  'midi.py',
   'vulkan.py',
   'terminal.py',
   'file.py',

bottles/backend/utils/midi.py

@@ -0,0 +1,110 @@
+# midi.py
+#
+# Copyright 2025 The Bottles Contributors
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, in version 3 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from typing import Self
+
+from ctypes import c_void_p
+from fluidsynth import cfunc, Synth  # type: ignore [import-untyped]
+
+from bottles.backend.logger import Logger
+from bottles.backend.models.config import BottleConfig
+from bottles.backend.wine.reg import Reg
+
+logging = Logger()
+
+
+class FluidSynth:
+    """FluidSynth instance bounded to a unique SoundFont (.sf2, .sf3) file."""
+
+    __active_instances: dict[int, Self] = {}
+
+    @classmethod
+    def find_or_create(cls, soundfont_path: str) -> Self:
+        """
+        Search for running FluidSynth instance and return it.
+        If nonexistent, create and add it to active ones beforehand.
+        """
+
+        for fs in cls.__active_instances.values():
+            if fs.soundfont_path == soundfont_path:
+                fs.program_count += 1
+                return fs
+
+        fs = cls(soundfont_path)
+        cls.__active_instances[fs.id] = fs
+        return fs
+
+    def __init__(self, soundfont_path: str):
+        """Build a new FluidSynth object from SoundFont file path."""
+        self.soundfont_path = soundfont_path
+        self.id = self.__get_vacant_id()
+        self.__start()
+        self.program_count = 1
+
+    @classmethod
+    def __get_vacant_id(cls) -> int:
+        """Get smallest 0-indexed ID currently not in use by a SoundFont."""
+        n = len(cls.__active_instances)
+        return next(i for i in range(n + 1) if i not in cls.__active_instances)
+
+    def __start(self):
+        """Start FluidSynth synthetizer with loaded SoundFont."""
+        logging.info(
+            "Starting new FluidSynth server with SoundFont"
+            f" #{self.id} ('{self.soundfont_path}')…"
+        )
+        synth = Synth(channels=16)
+        synth.start()
+        sfid = synth.sfload(self.soundfont_path)
+        synth.program_select(0, sfid, 0, 0)
+        self.synth = synth
+
+    def register_as_current(self, config: BottleConfig):
+        """
+        Update Wine registry with this instance's ID, instructing
+        MIDI mapping to load the correct instrument set on program startup.
+        """
+        reg = Reg(config)
+        reg.add(
+            key="HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Multimedia\\MIDIMap",
+            value="CurrentInstrument",
+            data=f"#{self.id}",
+            value_type="REG_SZ",
+        )
+
+    def decrement_program_counter(self):
+        """Decrement program counter; if it reaches zero, delete this instance."""
+        self.program_count -= 1
+        if self.program_count == 0:
+            self.__delete()
+
+    def __delete(self):
+        """Kill underlying synthetizer and remove FluidSynth instance from dict."""
+
+        def __delete_synth(synth: Synth):
+            """Bind missing function and run deletion routines."""
+            delete_fluid_midi_driver = cfunc(
+                "delete_fluid_midi_driver", c_void_p, ("driver", c_void_p, 1)
+            )
+            delete_fluid_midi_driver(synth.midi_driver)
+            synth.delete()
+
+        logging.info(
+            "Killing FluidSynth server with SoundFont"
+            f" #{self.id} ('{self.soundfont_path}')…"
+        )
+        __delete_synth(self.synth)
+        self.__active_instances.pop(self.id)

bottles/backend/wine/executor.py

@@ -9,6 +9,7 @@
 from bottles.backend.models.config import BottleConfig
 from bottles.backend.models.result import Result
 from bottles.backend.utils.manager import ManagerUtils
+from bottles.backend.utils.midi import FluidSynth
 from bottles.backend.wine.cmd import CMD
 from bottles.backend.wine.explorer import Explorer
 from bottles.backend.wine.msiexec import MsiExec
@@ -33,6 +34,7 @@ def __init__(
         pre_script: str | None = None,
         post_script: str | None = None,
         cwd: str | None = None,
+        midi_soundfont: str | None = None,
         monitoring: list | None = None,
         program_dxvk: bool | None = None,
         program_vkd3d: bool | None = None,
@@ -62,12 +64,20 @@ def __init__(
         self.pre_script = pre_script
         self.post_script = post_script
         self.cwd = self.__get_cwd(cwd)
+        self.midi_soundfont = midi_soundfont
         self.monitoring = monitoring
         self.use_gamescope = program_gamescope
         self.use_virt_desktop = program_virt_desktop
 
         env_dll_overrides = []
 
+        self.fluidsynth = None
+        if (soundfont_path := midi_soundfont) not in (None, ""):
+            # FluidSynth instance is bound to WineExecutor as a member to control
+            # the former's lifetime (deleted when no more references from executors)
+            self.fluidsynth = FluidSynth.find_or_create(soundfont_path)
+            self.fluidsynth.register_as_current(config)
+
         # None = use global DXVK value
         if program_dxvk is not None:
             # DXVK is globally activated, but disabled for the program
@@ -122,6 +132,7 @@ def run_program(cls, config: BottleConfig, program: dict, terminal: bool = False
             pre_script=program.get("pre_script"),
             post_script=program.get("post_script"),
             cwd=program.get("folder"),
+            midi_soundfont=program.get("midi_soundfont"),
             terminal=terminal,
             program_dxvk=program.get("dxvk"),
             program_vkd3d=program.get("vkd3d"),
@@ -212,6 +223,7 @@ def run_cli(self):
             pre_script=self.pre_script,
             post_script=self.post_script,
             cwd=self.cwd,
+            midi_soundfont=self.midi_soundfont,
         )
         return Result(status=True, data={"output": res})
 
@@ -278,6 +290,7 @@ def __launch_exe(self):
             pre_script=self.pre_script,
             post_script=self.post_script,
             cwd=self.cwd,
+            midi_soundfont=self.midi_soundfont,
         )
         res = winecmd.run()
         self.__set_monitors()
@@ -316,6 +329,7 @@ def __launch_with_starter(self):
             pre_script=self.pre_script,
             post_script=self.post_script,
             cwd=self.cwd,
+            midi_soundfont=self.midi_soundfont,
         )
         self.__set_monitors()
         return Result(status=True, data={"output": res})
@@ -349,3 +363,8 @@ def __set_monitors(self):
         winedbg = WineDbg(self.config, silent=True)
         for m in self.monitoring:
             winedbg.wait_for_process(name=m)
+
+    def __del__(self):
+        """On exit, kill FluidSynth instance if this was the last executor using it."""
+        if self.fluidsynth:
+            self.fluidsynth.decrement_program_counter()

bottles/backend/wine/start.py

@@ -18,6 +18,7 @@ def run(
         pre_script: str | None = None,
         post_script: str | None = None,
         cwd: str | None = None,
+        midi_soundfont: str | None = None,
     ):
         winepath = WinePath(self.config)
 
@@ -40,6 +41,7 @@ def run(
             pre_script=pre_script,
             post_script=post_script,
             cwd=cwd,
+            midi_soundfont=midi_soundfont,
             minimal=False,
             action_name="run",
         )

bottles/backend/wine/winecommand.py

@@ -99,6 +99,7 @@ def __init__(
         pre_script: str | None = None,
         post_script: str | None = None,
         cwd: str | None = None,
+        midi_soundfont: str | None = None,
     ):
         _environment = environment.copy()
         self.config = self._get_config(config)
@@ -112,7 +113,7 @@ def __init__(
             else self.config.Parameters.gamescope
         )
         self.command = self.get_cmd(
-            command, pre_script, post_script, environment=_environment
+            command, pre_script, post_script, midi_soundfont, environment=_environment
         )
         self.terminal = terminal
         self.env = self.get_env(_environment)
@@ -488,6 +489,7 @@ def get_cmd(
         command,
         pre_script: str | None = None,
         post_script: str | None = None,
+        midi_soundfont: str | None = None,
         return_steam_cmd: bool = False,
         return_clean_cmd: bool = False,
         environment: dict | None = None,

bottles/backend/wine/wineprogram.py

@@ -45,6 +45,7 @@ def launch(
         pre_script: str | None = None,
         post_script: str | None = None,
         cwd: str | None = None,
+        midi_soundfont: str | None = None,
         action_name: str = "launch",
     ):
         if environment is None:
@@ -72,6 +73,7 @@ def launch(
             pre_script=pre_script,
             post_script=post_script,
             cwd=cwd,
+            midi_soundfont=midi_soundfont,
             arguments=program_args,
         )
 

bottles/frontend/cli.py

@@ -670,6 +670,7 @@ def run_program(self):
             program.get("pre_script", None)
             program.get("post_script", None)
             program.get("folder", None)
+            program.get("midi_soundfont", None)
 
             program.get("dxvk")
             program.get("vkd3d")

bottles/frontend/filters.py

@@ -16,37 +16,45 @@
 
 from gettext import gettext as _
 
-from gi.repository import Gtk
+from gi.repository import Gio, GObject, Gtk
 
 
 def add_executable_filters(dialog):
-    filter = Gtk.FileFilter()
-    filter.set_name(_("Supported Executables"))
     # TODO: Investigate why `filter.add_mime_type(...)` does not show filter in all distributions.
     # Intended MIME types are:
     #   - `application/x-ms-dos-executable`
     #   - `application/x-msi`
-    filter.add_pattern("*.exe")
-    filter.add_pattern("*.msi")
+    __set_filter(dialog, _("Supported Executables"), ["*.exe", "*.msi"])
+
 
-    dialog.add_filter(filter)
+def add_soundfont_filters(dialog):
+    __set_filter(dialog, _("Supported SoundFonts"), ["*.sf2", "*.sf3"])
 
 
 def add_yaml_filters(dialog):
-    filter = Gtk.FileFilter()
-    filter.set_name("YAML")
     # TODO: Investigate why `filter.add_mime_type(...)` does not show filter in all distributions.
     # Intended MIME types are:
     #   - `application/yaml`
-    filter.add_pattern("*.yml")
-    filter.add_pattern("*.yaml")
-
-    dialog.add_filter(filter)
+    __set_filter(dialog, "YAML", ["*.yaml", "*.yml"])
 
 
 def add_all_filters(dialog):
-    filter = Gtk.FileFilter()
-    filter.set_name(_("All Files"))
-    filter.add_pattern("*")
+    __set_filter(dialog, _("All Files"), ["*"])
+
 
-    dialog.add_filter(filter)
+def __set_filter(dialog: GObject.Object, name: str, patterns: list[str]):
+    """Set dialog named file filter from list of extension patterns."""
+
+    filter = Gtk.FileFilter()
+    filter.set_name(name)
+    for pattern in patterns:
+        filter.add_pattern(pattern)
+
+    if isinstance(dialog, Gtk.FileDialog):
+        filters = dialog.get_filters() or Gio.ListStore.new(Gtk.FileFilter)
+        filters.append(filter)
+        dialog.set_filters(filters)
+    elif isinstance(dialog, Gtk.FileChooserNative):
+        dialog.add_filter(filter)
+    else:
+        raise TypeError

bottles/frontend/launch-options-dialog.blp

@@ -140,6 +140,37 @@ template $LaunchOptionsDialog: Adw.Window {
             }
           }
         }
+
+        Adw.ActionRow action_midi_soundfont {
+          activatable-widget: btn_midi_soundfont;
+          title: _("MIDI SoundFont");
+          subtitle: _("Choose a custom SoundFont for MIDI playback.");
+
+          Box {
+            spacing: 6;
+
+            Button btn_midi_soundfont_reset {
+              tooltip-text: _("Reset to Default");
+              valign: center;
+              visible: false;
+              icon-name: "edit-undo-symbolic";
+
+              styles [
+                "flat",
+              ]
+            }
+
+            Button btn_midi_soundfont {
+              tooltip-text: _("Choose a SoundFont");
+              valign: center;
+              icon-name: "document-open-symbolic";
+
+              styles [
+                "flat",
+              ]
+            }
+          }
+        }
       }
 
       Adw.PreferencesGroup {