Update app.py

app.py

@@ -53,13 +53,14 @@ class MIDIManager:
         self.synthesizer = MidiSynthesizer(self.soundfont_path)
         self.loaded_midi = {}  # midi_id: (file_path, midi_obj)
         self.modified_files = []  # Stores (midi_base64, audio_base64) tuples
+        self.example_variations = {}  # midi_id: (midi_base64, audio_base64) for pre-generated examples
         self.is_playing = False
         self.instruments = self.random_instrument_set()
         self.drum_beat = self.create_drum_beat()
         self.starter_midi = self.create_starter_midi()
-        self.example_files = self.load_example_midis()
         self.loaded_midi["starter"] = ("Starter MIDI", self.starter_midi)
         self.preload_default_midi()
+        self.load_example_midis()  # Pre-generate example variations
 
     def random_instrument_set(self):
         instrument_pool = [0, 24, 32, 48]  # Piano, Guitar, Bass, Strings
@@ -69,12 +70,12 @@ class MIDIManager:
         return [(36, 100, 0), (42, 80, 50), (38, 90, 100), (42, 80, 150)]  # Kick, hi-hat, snare, hi-hat
 
     def create_starter_midi(self):
-        midi = MIDI.MIDIFile(5)  # 4 instruments + 1 drum track
+        midi = MIDI.MIDIFile(5)
         for i, inst in enumerate(self.instruments):
             midi.addTrack()
             midi.addProgramChange(i, 0, 0, inst)
             for t in range(0, 400, 100):
-                note = random.randint(60, 84)  # C4 to C6
+                note = random.randint(60, 84)
                 midi.addNote(i, 0, note, t, 100, 100)
         midi.addTrack()
         for note, vel, time in self.drum_beat:
@@ -97,23 +98,16 @@ class MIDIManager:
                 continue
             midi_id = f"example_{len(examples)}"
             midi = MIDI.load(file_path)
-            new_midi = MIDI.MIDIFile(5)
-            notes, _ = self.extract_notes_and_instruments(midi)
-            for i, inst in enumerate(self.instruments):
-                new_midi.addTrack()
-                new_midi.addProgramChange(i, 0, 0, inst)
-                for note, vel, time in notes:
-                    new_midi.addNote(i, 0, note, time, 100, vel)
-            new_midi.addTrack()
-            for note, vel, time in self.drum_beat:
-                new_midi.addNote(4, 9, note, time, 100, vel)
-            examples[midi_id] = (file_path, new_midi)
-        self.loaded_midi.update(examples)
+            self.loaded_midi[midi_id] = (file_path, midi)
+            # Pre-generate variation for each example
+            midi_data, audio_data = self.generate_variation(midi_id)
+            examples[midi_id] = (midi_data, audio_data)
+        self.example_variations = examples
         return examples
 
     def load_midi(self, file_path):
         midi = MIDI.load(file_path)
-        midi_id = f"midi_{len(self.loaded_midi) - len(self.example_files) - 1}"
+        midi_id = f"midi_{len(self.loaded_midi) - len(self.example_variations) - 1}"
         self.loaded_midi[midi_id] = (file_path, midi)
         return midi_id
 
@@ -158,9 +152,8 @@ class MIDIManager:
         with open(temp_midi, 'wb') as f:
             f.write(midi_output.getvalue())
         audio_output = io.BytesIO()
-        # Placeholder for audio rendering; needs fluidsynth or similar
         self.synthesizer.play_midi(new_midi)
-        audio_data = None  # See Notes below
+        audio_data = None  # Placeholder; see Notes
         if os.path.exists(temp_midi):
             os.remove(temp_midi)
         
@@ -215,6 +208,9 @@ def create_download_list():
 def get_midi_choices():
     return [(os.path.basename(path), midi_id) for midi_id, (path, _) in midi_processor.loaded_midi.items()]
 
+def get_example_choices():
+    return [(os.path.basename(path), midi_id) for midi_id, (path, _) in midi_processor.loaded_midi.items() if midi_id.startswith("example")]
+
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     parser.add_argument("--port", type=int, default=7860)
@@ -249,20 +245,17 @@ if __name__ == "__main__":
 
             # Tab 2: Examples
             with gr.Tab("Examples"):
-                example_select = gr.Dropdown(label="Select Example", choices=get_midi_choices(), value=None)
+                example_select = gr.Dropdown(label="Select Example", choices=get_example_choices(), value=None)
                 example_output = gr.Audio(label="Example Preview", type="bytes", autoplay=True)
                 
                 def load_example(midi_id):
-                    if not midi_id:
+                    if not midi_id or midi_id not in midi_processor.example_variations:
                         return None
-                    midi_data, audio_data = midi_processor.generate_variation(midi_id)
+                    midi_data, audio_data = midi_processor.example_variations[midi_id]
                     midi_processor.play_with_loop(midi_data)
-                    return io.BytesIO(base64.b64decode(midi_data)), create_download_list()
+                    return io.BytesIO(base64.b64decode(midi_data))
                 
-                example_select.change(load_example, inputs=[example_select], 
-                                    outputs=[example_output, "downloads"])
-                gr.State(get_midi_choices()).change(lambda choices: gr.update(choices=choices), 
-                                                  inputs=[gr.State()], outputs=[example_select])
+                example_select.change(load_example, inputs=[example_select], outputs=[example_output])
 
             # Tab 3: Generate & Perform
             with gr.Tab("Generate & Perform"):