Nextcord机器人play命令报错：FFmpeg未找到及FFmpegPCMAudio属性缺失

运行基于Nextcord的Discord机器人play命令时，会触发两类错误：

• 首先抛出 nextcord.errors.ClientException，提示ffmpeg未找到
• 随后引发 AttributeError，提示**'FFmpegPCMAudio'对象不存在'_process'属性**

相关代码 #

@bot.command()
async def play(ctx, url):
    global is_playing
    if not ctx.author.voice:
        await ctx.send("You are not in a voice channel.")
        return

    voice_channel = ctx.author.voice.channel

    if not voice_channel:
        await ctx.send("You are not in a voice channel.")
        return

    voice_client = nextcord.utils.get(bot.voice_clients, guild=ctx.guild)

    if not voice_client:
        voice_client = await voice_channel.connect()

    if is_playing:
        await ctx.send("The bot is already playing audio.")
        return

    url_youtube = url

    ydl_opts = {
        'format': 'bestaudio/best',
        'extractaudio': True,
        'audioformat': 'mp3',
        'outtmpl': 'C:\\Users\\alshh\\Videos\\%(title)s.%(ext)s',
        'yes-playlist': True,
        'playlist-random': True,
        'embed-thumbnail': True,
    }

    with youtube_dl.YoutubeDL(ydl_opts) as ydl:
        info_dict = ydl.extract_info(url_youtube, download=True)
        if 'entries' in info_dict:
            for entry in info_dict['entries']:
                print(f"Downloaded: {entry['title']}.{entry['ext']}")
        else:
            print(f"Downloaded: {info_dict['title']}.{info_dict['ext']}")

    is_playing = True
    player = nextcord.FFmpegPCMAudio(f"C:\\Users\\alshh\\Videos\\{info_dict['title']}.{info_dict['ext']}")
    voice_client.play(player, after=lambda e: play_next(ctx) if e else None)

完整报错堆栈 #

Ignoring exception in command play:
Traceback (most recent call last):
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\ext\commands\core.py", line 143, in wrapped
    ret = await coro(*args, **kwargs)
  File "c:/Users/alshh/.vscode/discord/Recording/1.py", line 63, in play
    player = nextcord.FFmpegPCMAudio(f"C:\\Users\\alshh\\Videos\\{info_dict['title']}.{info_dict['ext']}")
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\player.py", line 281, in __init__
    super().__init__(source, executable=executable, args=args, **subprocess_kwargs)
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\player.py", line 144, in __init__
    self._process: subprocess.Popen = self._spawn_process(args, **kwargs)
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\player.py", line 163, in _spawn_process
    raise ClientException(executable + " was not found.") from None
nextcord.errors.ClientException: ffmpeg was not found.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\ext\commands\bot.py", line 1355, in invoke
    await ctx.command.invoke(ctx)
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\ext\commands\core.py", line 1003, in invoke
    await injected(*ctx.args, **ctx.kwargs)
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\ext\commands\core.py", line 152, in wrapped
    raise CommandInvokeError(exc) from exc
nextcord.ext.commands.errors.CommandInvokeError: Command raised an exception: ClientException: ffmpeg was not found.
Exception ignored in: <function AudioSource.__del__ at 0x000002881ADFF0D0>
Traceback (most recent call last):
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\player.py", line 95, in __del__
    self.cleanup()
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\player.py", line 214, in cleanup
    self._kill_process()
  File "C:\Users\alshh\AppData\Local\Programs\Python\Python38\lib\site-packages\nextcord\player.py", line 170, in _kill_process
    proc = self._process
AttributeError: 'FFmpegPCMAudio' object has no attribute '_process'

解决方案 #

1. 安装并配置FFmpeg

这是根本问题，所有后续错误都是FFmpeg未找到导致的：

• 下载对应系统的FFmpeg安装包，解压到本地路径（比如C:\ffmpeg）
• 方法一：配置系统环境变量
  找到系统PATH变量，添加FFmpeg的bin目录路径（比如C:\ffmpeg\bin），配置完成后重启命令行和Python环境
• 方法二：代码中指定FFmpeg路径
  如果不想配置环境变量，直接在创建FFmpegPCMAudio时指定executable参数：

  player = nextcord.FFmpegPCMAudio(
      f"C:\\Users\\alshh\\Videos\\{info_dict['title']}.{info_dict['ext']}",
      executable="C:\\ffmpeg\\bin\\ffmpeg.exe"  # 替换成你的FFmpeg实际路径
  )
  

• 验证配置：打开命令行输入ffmpeg -version，能正常输出版本信息即为配置成功

2. 关于_process属性缺失的错误

这个错误是FFmpeg初始化失败的衍生问题：当FFmpeg未找到时，FFmpegPCMAudio对象的_process属性还没被创建，但对象销毁时的cleanup()方法仍尝试访问该属性，从而抛出异常。只要解决了FFmpeg的问题，这个错误会自动消失。

3. 额外优化建议

• 替换全局变量is_playing：直接使用voice_client.is_playing()方法判断机器人是否正在播放，避免全局变量的潜在问题：

  if voice_client.is_playing():
      await ctx.send("The bot is already playing audio.")
      return
  

• 修复播放列表处理逻辑：当前代码下载了播放列表的所有条目，但只播放了第一个条目。建议维护一个播放队列，在play_next函数中依次取出队列中的音频文件进行播放
• 替换youtube_dl为yt-dlp：youtube_dl已停止维护，yt-dlp是其活跃分支，支持更多站点和最新特性，安装命令：pip install yt-dlp，代码中只需将youtube_dl替换为yt_dlp即可

内容的提问来源于stack exchange，提问作者Faisal