我已经开始了一个项目，我需要使用一个名为 MuJoCo Mujoco Documentation 的开源软件。它是一款偏向RL（强化学习）的物理模拟软件。由于我正在开发的应用程序是创建人工智能，因此为了方便起见，我也使用 python 进行工作。
我遇到的问题是 MuJoCo 使用一个名为“mediapy”的库来可视化帧序列（视频），而该库又使用一个名为“ffmpeg”的库。问题是 mediapy 无法识别我的计算机（Mac、Intel）上安装了“ffmpeg”。当我深入研究源代码尝试查找问题时，我发现“mediapy”通过运行来检查“ffmpeg”的安装：
import shutil
import typing
import os
_Path = typing.Union[str, 'os.PathLike[str]']
class _Config:
ffmpeg_name_or_path: _Path = 'ffmpeg'
show_save_dir: _Path | None = None
_config = _Config()
def _search_for_ffmpeg_path() -> str | None:
"""Returns a path to the ffmpeg program, or None if not found."""
if filename := shutil.which(_config.ffmpeg_name_or_path):
return str(filename)
return None
然后我导航到所有已安装库所在的文件夹 opt/anaconda3/envs/myenv/lib/python3.10/site-packages 并发现“ffmpeg”文件夹包含所有其他库包含的所有内容。所以它显然存在于那里。但是，当我运行上面的代码时，我得到“无”的返回。我显然错过了一些明显的东西，但我似乎找不到它。
仅供参考，这是提示问题的代码：
tippe_top = """
<mujoco model="tippe top">
<option integrator="RK4"/>
<asset>
<texture name="grid" type="2d" builtin="checker" rgb1=".1 .2 .3"
rgb2=".2 .3 .4" width="300" height="300"/>
<material name="grid" texture="grid" texrepeat="8 8" reflectance=".2"/>
</asset>
<worldbody>
<geom size=".2 .2 .01" type="plane" material="grid"/>
<light pos="0 0 .6"/>
<camera name="closeup" pos="0 -.1 .07" xyaxes="1 0 0 0 1 2"/>
<body name="top" pos="0 0 .02">
<freejoint/>
<geom name="ball" type="sphere" size=".02" />
<geom name="stem" type="cylinder" pos="0 0 .02" size="0.004 .008"/>
<geom name="ballast" type="box" size=".023 .023 0.005" pos="0 0 -.015"
contype="0" conaffinity="0" group="3"/>
</body>
</worldbody>
<keyframe>
<key name="spinning" qpos="0 0 0.02 1 0 0 0" qvel="0 0 0 0 1 200" />
</keyframe>
</mujoco>
"""
model = mujoco.MjModel.from_xml_string(tippe_top)
renderer = mujoco.Renderer(model)
data = mujoco.MjData(model)
duration = 7 # (seconds)
framerate = 60 # (Hz)
# Simulate and display video.
frames = []
mujoco.mj_resetDataKeyframe(model, data, 0) # Reset the state to keyframe 0
while data.time < duration:
mujoco.mj_step(model, data)
if len(frames) < data.time * framerate:
renderer.update_scene(data, "closeup")
pixels = renderer.render()
frames.append(pixels)
media.show_video(frames, fps=framerate)
随后出现错误消息：
{
"name": "RuntimeError",
"message": "Program 'ffmpeg' is not found; perhaps install ffmpeg using 'apt install ffmpeg'.",
"stack": "---------------------------------------------------------------------------
RuntimeError Traceback (most recent call last)
Cell In[4], line 14
11 pixels = renderer.render()
12 frames.append(pixels)
---> 14 media.show_video(frames, fps=framerate)
File ~/opt/anaconda3/envs/Exjobb/lib/python3.10/site-packages/mediapy/__init__.py:1858, in show_video(images, title, **kwargs)
1835 def show_video(
1836 images: Iterable[_NDArray], *, title: str | None = None, **kwargs: Any
1837 ) -> str | None:
1838 \"\"\"Displays a video in the IPython notebook and optionally saves it to a file.
1839
1840 See `show_videos`.
(...)
1856 html string if `return_html` is `True`.
1857 \"\"\"
-> 1858 return show_videos([images], [title], **kwargs)
File ~/opt/anaconda3/envs/Exjobb/lib/python3.10/site-packages/mediapy/__init__.py:1940, in show_videos(videos, titles, width, height, downsample, columns, fps, bps, qp, codec, ylabel, html_class, return_html, **kwargs)
1938 video = [resize_image(image, (h, w)) for image in video]
1939 first_image = video[0]
-> 1940 data = compress_video(
1941 video, metadata=metadata, fps=fps, bps=bps, qp=qp, codec=codec
1942 )
1943 if title is not None and _config.show_save_dir:
1944 suffix = _filename_suffix_from_codec(codec)
File ~/opt/anaconda3/envs/Exjobb/lib/python3.10/site-packages/mediapy/__init__.py:1777, in compress_video(images, codec, **kwargs)
1775 with tempfile.TemporaryDirectory() as directory_name:
1776 tmp_path = pathlib.Path(directory_name) / f'file{suffix}'
-> 1777 write_video(tmp_path, images, codec=codec, **kwargs)
1778 return tmp_path.read_bytes()
File ~/opt/anaconda3/envs/Exjobb/lib/python3.10/site-packages/mediapy/__init__.py:1747, in write_video(path, images, **kwargs)
1745 dtype = np.dtype(np.uint16)
1746 kwargs = {'metadata': getattr(images, 'metadata', None), **kwargs}
-> 1747 with VideoWriter(path, shape=shape, dtype=dtype, **kwargs) as writer:
1748 for image in images:
1749 writer.add_image(image)
File ~/opt/anaconda3/envs/Exjobb/lib/python3.10/site-packages/mediapy/__init__.py:1567, in VideoWriter.__enter__(self)
1566 def __enter__(self) -> 'VideoWriter':
-> 1567 ffmpeg_path = _get_ffmpeg_path()
1568 input_pix_fmt = self._get_pix_fmt(self.dtype, self.input_format)
1569 try:
File ~/opt/anaconda3/envs/Exjobb/lib/python3.10/site-packages/mediapy/__init__.py:1167, in _get_ffmpeg_path()
1165 path = _search_for_ffmpeg_path()
1166 if not path:
-> 1167 raise RuntimeError(
1168 f\"Program '{_config.ffmpeg_name_or_path}' is not found;\"
1169 \" perhaps install ffmpeg using 'apt install ffmpeg'.\"
1170 )
1171 return path
RuntimeError: Program 'ffmpeg' is not found; perhaps install ffmpeg using 'apt install ffmpeg'."
}
非常感谢任何帮助。
我尝试更改“shutil.which”命令正在搜索的文件的名称。我尝试重新安装库并尝试不同的库（似乎有两个“ffmpeg-python”，版本0.2和ffmpeg（在我的目录中显示为“imageio_ffmpeg”）版本0.4.9（但它说1.4）在 pip 网站上））。
moviepyffmpegffmpeg-pythonimageio_ffmpegsite-packagesshutil.which()您可以通过在命令行中输入
ffmpegffmpeg如果您有 Homebrew，您可以使用
安装该工具brew install ffmpeg
或通过 ffmpeg.org.