feat: Add Impulse Tracker (.it) files exporting feature

- Audio samples are saved as uncompressed, normalized, 16-bit, single-channel data
- A sample is mapped to an instrument
- One empty sample and an empty instrument are added to fix the weird pitch shifting of the last sample
- The attached message is not written because I'm lazy
- Due to limitations of the Impulse Tracker format:
 - Most of the text fields are truncated to 26 characters, except channel names, which are limited to 20 characters
 - A note may not have its volume, panning, and pitch applied because the .it format only has a volume column and an effect column
 - If the length of a song is more than 40000 ticks, the rest of the song will not be saved
- It seems like different programs play the exported file differently. Notably, the sample' pitch is sometimes shifted.

Author: IoeCmcomc

common.py

@@ -20,6 +20,10 @@
 import sys
 from collections import namedtuple
 from os.path import abspath, dirname, join, normpath
+from functools import lru_cache
+from typing import Optional
+
+from pydub import AudioSegment
 
 # from main import __file__ as __mainfile__
 
@@ -225,16 +229,24 @@
 )
 
 NBS_PITCH_IN_MIDI_PITCHBEND = 40.96
+SOUND_FOLDER = "sounds"
 
-
-BASE_RESOURCE_PATH = None
+BASE_RESOURCE_PATH = ''
 if getattr(sys, 'frozen', False): # PyInstaller
     BASE_RESOURCE_PATH = sys._MEIPASS # type: ignore
 elif '__compiled__' in globals(): # Nuitka
     BASE_RESOURCE_PATH = dirname(__file__)
 else:
     BASE_RESOURCE_PATH = abspath('.')
-assert BASE_RESOURCE_PATH is not None
+assert BASE_RESOURCE_PATH != ''
+
+def resource_path(*args: str):
+    return normpath(join(BASE_RESOURCE_PATH, *args))
 
-def resource_path(*args):
-    return normpath(join(BASE_RESOURCE_PATH, *args))
+@lru_cache(maxsize=32)
+def load_sound(path: str) -> AudioSegment:
+    """A patched version of nbswave.audio.load_song() which caches loaded sounds"""
+    if not path:
+        return AudioSegment.empty()
+    else:
+        return AudioSegment.from_file(path)

customwidgets/__init__.py

@@ -15,44 +15,3 @@
 # License: MIT license
 # Source codes are hosted on: GitHub (https://github.com/IoeCmcomc/NBSTool)
 # ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
-
-
-if __name__ == '__init__': # Pygubu import call
-    from wrapmessage import WrapMessage
-    from checkablelabelframe import CheckableLabelFrame
-else: # Normal import call
-    from .wrapmessage import WrapMessage
-    from .checkablelabelframe import CheckableLabelFrame
-
-from packaging.version import Version
-import pygubu
-
-if Version(pygubu.__version__) >= Version('0.24'):
-    from pygubu.component.builderobject import BuilderObject
-    from pygubu.api.v1 import register_widget
-else:
-        from pygubu import BuilderObject, register_widget    
-
-class WrapMessageBuilder(BuilderObject):
-    class_ = WrapMessage
-
-    OPTIONS_STANDARD = ('anchor', 'background', 'borderwidth', 'cursor', 'font',
-                        'foreground', 'highlightbackground', 'highlightcolor',
-                        'highlightthickness', 'padx', 'pady', 'relief', 'takefocus',
-                        'text', 'textvariable')
-    OPTIONS_SPECIFIC =  ('aspect', 'justify', 'width', 'padding')
-    properties = OPTIONS_STANDARD + OPTIONS_SPECIFIC
-
-class CheckableLabelFrameBuilder(BuilderObject):
-    class_ = CheckableLabelFrame
-    container = True
-
-    OPTIONS_STANDARD = ('cursor', 'takefocus', 'style')
-    OPTIONS_SPECIFIC = ('borderwidth', 'relief', 'padding', 'height', 'width', 'labelanchor', 'text', 'underline', 'variable', 'command')
-    
-    properties = OPTIONS_STANDARD + OPTIONS_SPECIFIC
-
-register_widget('customwidgets.wrapmessage', WrapMessageBuilder,
-                'WrapMessage', ('tk', 'Custom'))
-register_widget('customwidgets.checkablelabelframe', CheckableLabelFrameBuilder,
-                'CheckableLabelFrame', ('ttk', 'Custom'))

customwidgets/builder.py

@@ -0,0 +1,54 @@
+# This file is a part of:
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+#  ███▄▄▄▄   ▀█████████▄     ▄████████     ███      ▄██████▄   ▄██████▄   ▄█
+#  ███▀▀▀██▄   ███    ███   ███    ███ ▀█████████▄ ███    ███ ███    ███ ███
+#  ███   ███   ███    ███   ███    █▀     ▀███▀▀██ ███    ███ ███    ███ ███
+#  ███   ███  ▄███▄▄▄██▀    ███            ███   ▀ ███    ███ ███    ███ ███
+#  ███   ███ ▀▀███▀▀▀██▄  ▀███████████     ███     ███    ███ ███    ███ ███
+#  ███   ███   ███    ██▄          ███     ███     ███    ███ ███    ███ ███
+#  ███   ███   ███    ███    ▄█    ███     ███     ███    ███ ███    ███ ███▌    ▄
+#   ▀█   █▀  ▄█████████▀   ▄████████▀     ▄████▀    ▀██████▀   ▀██████▀  █████▄▄██
+# __________________________________________________________________________________
+# NBSTool is a tool to work with .nbs (Note Block Studio) files.
+# Author: IoeCmcomc (https://github.com/IoeCmcomc)
+# Programming language: Python
+# License: MIT license
+# Source codes are hosted on: GitHub (https://github.com/IoeCmcomc/NBSTool)
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+
+
+try:
+    from pygubu.api.v1 import (
+        BuilderObject,
+        register_widget,
+    )
+except ImportError as e:
+    from pygubu import BuilderObject, register_widget # type: ignore
+
+from wrapmessage import WrapMessage
+from checkablelabelframe import CheckableLabelFrame
+
+class WrapMessageBuilder(BuilderObject): # type: ignore
+    class_ = WrapMessage
+
+    OPTIONS_STANDARD = ('anchor', 'background', 'borderwidth', 'cursor', 'font',
+                        'foreground', 'highlightbackground', 'highlightcolor',
+                        'highlightthickness', 'padx', 'pady', 'relief', 'takefocus',
+                        'text', 'textvariable')
+    OPTIONS_SPECIFIC =  ('aspect', 'justify', 'width', 'padding')
+    properties = OPTIONS_STANDARD + OPTIONS_SPECIFIC
+
+class CheckableLabelFrameBuilder(BuilderObject): # type: ignore
+    class_ = CheckableLabelFrame
+    container = True
+
+    OPTIONS_STANDARD = ('cursor', 'takefocus', 'style')
+    OPTIONS_SPECIFIC = ('borderwidth', 'relief', 'padding', 'height', 'width', 'labelanchor', 'text', 'underline', 'variable', 'command')
+    
+    properties = OPTIONS_STANDARD + OPTIONS_SPECIFIC
+
+register_widget(
+    'customwidgets.WrapMessage', WrapMessageBuilder, 'WrapMessage', ('tk', 'Custom'))
+register_widget(
+    'customwidgets.CheckableLabelFrame', CheckableLabelFrameBuilder,
+    'CheckableLabelFrame', ('ttk', 'Custom'))

main.py

@@ -63,7 +63,7 @@
 import logging
 import sys
 
-logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)
+# logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)
 
 import pygubu
 import pygubu.widgets.combobox
@@ -90,6 +90,7 @@
 from nbs2midi import nbs2midi
 from nbsio import NBS_VERSION, VANILLA_INSTS, Instrument, Layer, NbsSong, Note
 from lyric_parser import lyric2captions
+from nbs2impulsetracker import nbs2it
 
 __version__ = '1.3.0'
 
@@ -409,6 +410,8 @@ def on_fileTable_select(event):
                 2, state="normal" if selectionNotEmpty else "disable")
             exportMenu.entryconfig(
                 3, state="normal" if selectionNotEmpty else "disable")
+            exportMenu.entryconfig(
+                4, state="normal" if selectionNotEmpty else "disable")
 
         self.fileTable.bind("<<TreeviewSelect>>", on_fileTable_select)
 
@@ -735,6 +738,9 @@ def callAudioExportDialog(self):
 
     def callJsonExportDialog(self):
         JsonExportDialog(self.toplevel, self).run()
+    
+    def callImpulseExportDialog(self):
+        ImpulseExportDialog(self.toplevel, self).run()
 
     def callAboutDialog(self):
         dialogue = AboutDialog(self.toplevel, self)
@@ -1144,6 +1150,8 @@ def __init__(self, master, parent, fileExt: str, title: Optional[str], progressT
 
         self.exportModeChanged()
 
+        self.shouldCompactNotes = True
+
     def run(self):
         self.d.run()
 
@@ -1201,7 +1209,8 @@ async def work(dialog: ProgressDialog):
                     dialog.currentText.set(f"Current file: {filePath}")
                     # Prevent data from unintended changes
                     songData: NbsSong = deepcopy(songsData[i])
-                    compactNotes(songData, True)
+                    if self.shouldCompactNotes:
+                        compactNotes(songData, True)
                     songData.correctData()
                     dialog.currentProgress.set(10)  # 10%
                     await func(songData, filePath, dialog)
@@ -1257,6 +1266,25 @@ async def nbs2json(self, data: NbsSong, filepath: str, dialog: ProgressDialog):
         await sleep(0.001)
 
 
+def checkFFmpeg(ps: str = '') -> bool:
+    if not (which('ffmpeg') and which('ffprobe')):
+        instructionMsg = ''
+        if os.name == 'nt':
+            instructionMsg = """
+Make sure there are ffmpeg.exe and ffprobe.exe inside the ffmpeg/bin folder.
+If not, you can download ffmpeg then put these two files in ffmpeg/bin folder."""
+        elif os.name == 'posix':
+            instructionMsg = """
+Make sure the ffmpeg package is installed in the system.
+Use "sudo apt install ffmpeg" command to install ffmpeg."""
+        instructionMsg = "NBSTool can't find ffmpeg, which is required to render audio." + instructionMsg
+        if ps:
+            instructionMsg += '\n' + ps
+        showwarning("ffmpeg not found", instructionMsg)
+        return False
+    else:
+        return True
+
 class AudioExportDialog(ExportDialog):
     def __init__(self, master, parent):
         self.formatVar: tk.StringVar
@@ -1278,18 +1306,7 @@ def __init__(self, master, parent):
         self.stereo.set(True)  # type: ignore
         self.includeLocked.set(True)  # type: ignore
 
-        if not (which('ffmpeg') and which('ffprobe')):
-            instructionMsg = ''
-            if os.name == 'nt':
-                instructionMsg = """
-Make sure there are ffmpeg.exe and ffprobe.exe inside the ffmpeg/bin folder.
-If not, you can download ffmpeg then put these two files in ffmpeg/bin folder."""
-            elif os.name == 'posix':
-                instructionMsg = """
-Make sure the ffmpeg package is installed in the system.
-Use "sudo apt install ffmpeg" command to install ffmpeg."""
-            showwarning("ffmpeg not found",
-            "NBSTool can't find ffmpeg, which is required to render audio." + instructionMsg)
+        checkFFmpeg()
 
     def formatChanged(self, *args):
         self.fileExt = '.' + self.builder.get_object('formatCombo').current()
@@ -1307,6 +1324,14 @@ async def audioExport(self, data: NbsSong, filepath: str, dialog: ProgressDialog
                         ignore_missing_instruments=ignoreMissingSounds)
 
 
+class ImpulseExportDialog(ExportDialog):
+    def __init__(self, master, parent):
+        super().__init__(master, parent, '.it', "Impulse Tracker exporting",
+                         "Exporting {} files to Impulse Tracker format (.it)...", nbs2it)
+        
+        if not checkFFmpeg():
+            self.d.destroy()
+
 def parseFilePaths(string: str) -> tuple:
     strLen = len(string)
     ret: List[str] = []

nbs2audio.py

@@ -1,18 +1,39 @@
+# This file is a part of:
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+#  ███▄▄▄▄   ▀█████████▄     ▄████████     ███      ▄██████▄   ▄██████▄   ▄█
+#  ███▀▀▀██▄   ███    ███   ███    ███ ▀█████████▄ ███    ███ ███    ███ ███
+#  ███   ███   ███    ███   ███    █▀     ▀███▀▀██ ███    ███ ███    ███ ███
+#  ███   ███  ▄███▄▄▄██▀    ███            ███   ▀ ███    ███ ███    ███ ███
+#  ███   ███ ▀▀███▀▀▀██▄  ▀███████████     ███     ███    ███ ███    ███ ███
+#  ███   ███   ███    ██▄          ███     ███     ███    ███ ███    ███ ███
+#  ███   ███   ███    ███    ▄█    ███     ███     ███    ███ ███    ███ ███▌    ▄
+#   ▀█   █▀  ▄█████████▀   ▄████████▀     ▄████▀    ▀██████▀   ▀██████▀  █████▄▄██
+# __________________________________________________________________________________
+# NBSTool is a tool to work with .nbs (Note Block Studio) files.
+# Author: IoeCmcomc (https://github.com/IoeCmcomc)
+# Programming language: Python
+# License: MIT license
+# Source codes are hosted on: GitHub (https://github.com/IoeCmcomc/NBSTool)
+# ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
+
+
 from asyncio import sleep
 from os import environ
 from os import name as os_name
 from typing import Optional, Sequence
 
 from pydub import AudioSegment
 from pynbs import File, Header, Instrument, Layer, Note
+
+from common import load_sound
+
 from nbswave import SongRenderer, audio, nbs
 from nbswave.main import MissingInstrumentException
 
-from common import resource_path
+from common import resource_path, SOUND_FOLDER
 from nbsio import VANILLA_INSTS, NbsSong
 
-
-SOUND_FOLDER = resource_path('sounds')
+audio.load_sound = load_sound
 
 def convert(data: NbsSong) -> File:
     oldHeader = data.header