Pydroid用ピアノアプリ＋ラフマニノフピアノ協奏曲第2番1楽章デモ音源付き

```py import os # Pydroid3/Android 用 SDL オーディオドライバ os.environ['SDL_AUDIODRIVER'] = 'android' import tkinter as tk from tkinter import font import time import threading import math import numpy as np import pygame from mido import MidiFile class PianoApp: def __init__(self, root, midi_path): self.root = root self.root.title("ラフマニノフ: ピアノ協奏曲第2番 第1楽章 デモ") # pygame.mixer 初期化 pygame.mixer.init(frequency=44100, size=-16, channels=1, buffer=512) self.sound_cache = {} # フォント self.title_font = font.Font(family="Helvetica", size=16, weight="bold") self.key_font = font.Font(family="Helvetica", size=10) # ウィンドウサイズ w = min(1000, root.winfo_screenwidth()) h = min(400, root.winfo_screenheight()) root.geometry(f"{w}x{h+100}") # タイトル tk.Label(root, text="ラフマニノフ: ピアノ協奏曲第2番 第1楽章 (抜粋)", font=self.title_font).pack(pady=10) # Canvas self.canvas = tk.Canvas(root, width=w, height=h, bg="gray") self.canvas.pack() # MIDI からノートデータを生成 self.rachmaninoff_data = self.parse_midi_to_data(midi_path) # 再生／停止ボタン frame = tk.Frame(root) frame.pack(pady=5) tk.Button(frame, text="再生", command=self.start_playback, font=self.key_font).pack(side=tk.LEFT, padx=5) tk.Button(frame, text="停止", command=self.stop_playback, font=self.key_font).pack(side=tk.LEFT, padx=5) # 鍵盤サイズ self.white_w = 40 self.white_h = h self.black_w = 25 self.black_h = int(h * 0.6) # Canvas item ID → note/color マッピング self.id_to_note = {} self.id_to_color = {} # 鍵盤を描画 self.draw_keys(start_midi=36, num_keys=36) # デモ再生用スレッド self.playback_thread = None self.stop_flag = False # クリックで音を鳴らす self.canvas.bind("<Button-1>", self.on_click) def parse_midi_to_data(self, path): mid = MidiFile(path) events = [] note_on_times = {} current = 0.0 for msg in mid: current += msg.time if not msg.is_meta: if msg.type == 'note_on' and msg.velocity > 0: note_on_times.setdefault(msg.note, []).append(current) elif msg.type in ('note_off',) or (msg.type=='note_on' and msg.velocity==0): lst = note_on_times.get(msg.note) if lst: start = lst.pop(0) dur = current - start events.append((start, msg.note, dur)) events.sort(key=lambda x: x[0]) return events def draw_keys(self, start_midi, num_keys): note_names = ['C','C#','D','D#','E','F','F#','G','G#','A','A#','B'] white_positions = {} white_count = 0 # ① 白鍵の位置計算 for note in range(start_midi, start_midi+num_keys): if '#' not in note_names[note % 12]: x = white_count * self.white_w white_positions[note] = x white_count += 1 # ② 白鍵描画 for note, x in white_positions.items(): rect = self.canvas.create_rectangle( x, 0, x + self.white_w, self.white_h, fill="white", outline="black" ) self.id_to_note[rect] = note self.id_to_color[rect] = "white" # ③ 黒鍵描画 for note in range(start_midi, start_midi+num_keys): if '#' in note_names[note % 12]: prev = note - 1 if prev in white_positions: x0 = white_positions[prev] + self.white_w - self.black_w//2 rect = self.canvas.create_rectangle( x0, 0, x0 + self.black_w, self.black_h, fill="black", outline="black" ) self.canvas.tag_raise(rect) self.id_to_note[rect] = note self.id_to_color[rect] = "black" def on_click(self, event): items = self.canvas.find_overlapping(event.x, event.y, event.x, event.y) if not items: return item = items[-1] note = self.id_to_note.get(item) if note is not None: self.play_note(note, 0.5) def midi_to_freq(self, note): return 440.0 * (2 ** ((note - 69) / 12.0)) def generate_sound(self, note, duration): key = (note, duration) if key in self.sound_cache: return self.sound_cache[key] sr = 44100 n = int(duration * sr) t = np.linspace(0, duration, n, False) wave = 0.5 * np.sin(2 * math.pi * self.midi_to_freq(note) * t) audio = np.int16(wave * 32767) sound = pygame.sndarray.make_sound(audio) self.sound_cache[key] = sound return sound def play_note(self, note, duration): # 鍵盤ハイライト for item, n in self.id_to_note.items(): if n == note: orig = self.id_to_color[item] self.canvas.itemconfig(item, fill="red") self.root.after(int(duration*1000), lambda i=item, c=orig: self.canvas.itemconfig(i, fill=c)) # サウンド再生 snd = self.generate_sound(note, duration) snd.play() def playback(self): start = time.time() self.stop_flag = False for t, note, dur in self.rachmaninoff_data: if self.stop_flag: break now = time.time() - start if now < t: time.sleep(t - now) # UI スレッドに play_note をキュー self.root.after(0, lambda n=note, d=dur: self.play_note(n, d)) def start_playback(self): if self.playback_thread and self.playback_thread.is_alive(): return self.stop_flag = False self.playback_thread = threading.Thread(target=self.playback, daemon=True) self.playback_thread.start() def stop_playback(self): self.stop_flag = True pygame.mixer.stop() if self.playback_thread: self.playback_thread.join() if __name__ == "__main__": root = tk.Tk() # 同フォルダに置いたMIDIファイル名を指定してください。できればフルパスをおすすめします。ファイル名のみの場合、エラーか出ることがあります。 app = PianoApp(root, midi_path="/storage/ emulated/0/Download/con2_1.mid") root.mainloop() ```