app.py

import gradio as gr
from pydub import AudioSegment
import tempfile
import os

def process_audio(file, 
                  left_source,  # "left", "right", "mute"
                  right_source,  # "left", "right", "mute"
                  output_format  # "元のまま", "wav", "mp3", ...
                 ):
    # 入力フォーマットを取得
    original_format = os.path.splitext(file)[1][1:]  # 例: ".wav" → "wav"

    # ステレオで読み込み
    audio = AudioSegment.from_file(file)
    left, right = audio.split_to_mono()

    # ソース選択
    def get_channel(source):
        if source == "left":
            return left
        elif source == "right":
            return right
        else:  # mute
            return AudioSegment.silent(duration=len(audio))

    new_left = get_channel(left_source)
    new_right = get_channel(right_source)

    # ステレオ再構築
    combined = AudioSegment.from_mono_audiosegments(new_left, new_right)

    # 出力フォーマットを決定
    export_format = original_format if output_format == "元のまま" else output_format
    suffix = f".{export_format}"

    # 一時ファイルに保存
    with tempfile.NamedTemporaryFile(delete=False, suffix=suffix) as tmpfile:
        combined.export(tmpfile.name, format=export_format)
        return tmpfile.name

# UI設定
options = ["left", "right", "mute"]
format_options = ["元のまま", "wav", "mp3", "ogg", "flac"]

theme = gr.themes.Base(
    primary_hue="sky",
    neutral_hue="slate",
    text_size="lg",
    radius_size="sm",
    font=[gr.themes.GoogleFont('Zen Maru Gothic'), 'ui-sans-serif', 'system-ui', 'sans-serif'],
    font_mono=[gr.themes.GoogleFont('Kosugi Maru'), 'ui-monospace', 'Consolas', 'monospace'],
).set(
    body_text_weight='500',
    embed_radius='*radius_xxs',
    border_color_primary='*neutral_400',
    border_color_primary_dark='*neutral_400',
    shadow_drop='*block_shadow',
    shadow_drop_lg='*shadow_drop',
    button_border_width='*block_border_width',
    button_border_width_dark='*block_border_width',
    button_primary_shadow='*shadow_drop',
    button_primary_shadow_hover='*shadow_inset',
    button_primary_shadow_active='*shadow_drop',
    button_secondary_shadow='*shadow_drop',
    button_secondary_shadow_hover='*shadow_inset',
    button_secondary_shadow_active='*shadow_drop',
    button_large_padding='*spacing_md',
    button_large_radius='*radius_sm',
    button_small_radius='*radius_xxl',
    button_primary_background_fill='*primary_100',
    button_primary_background_fill_dark='*primary_500',
    button_primary_background_fill_hover_dark='*button_secondary_background_fill_hover',
)

demo = gr.Interface(
    fn=process_audio,
    inputs=[
        gr.Audio(type="filepath", label="音声ファイル（ステレオ）"),
        gr.Radio(choices=options, value="left", label="左チャンネルに流す音"),
        gr.Radio(choices=options, value="right", label="右チャンネルに流す音"),
        gr.Dropdown(choices=format_options, value="元のまま", label="出力フォーマット")
    ],
    outputs=gr.Audio(label="出力音声（設定済みステレオ）"),
    title="ステレオチャンネル編集ツール",
    description="左・右チャンネルの音声ソースを個別に設定し、出力フォーマットを選んで保存できます。",
    theme=theme
)

if __name__ == "__main__":
    demo.launch(debug=True)