[Bug Report] Video Recording Wrapper Broken

[arhanjain]

Describe the bug

When wrapping the IsaacLab environment with the gym.wrappers.RecordVideo, I'm no longer able to get it to output videos successfully.

Steps to reproduce

import argparse
from omni.isaac.lab.app import AppLauncher

parser = argparse.ArgumentParser(description="test")
parser.add_argument(
    "--disable_fabric",
    action="store_true",
    default=False, help="Disable fabric and use USD I/O operations.",) 
parser.add_argument(
    "--num_envs", type=int, default=1, help="Number of environments to simulate."
)
parser.add_argument("--task", type=str, default=None, help="Name of the task.")

AppLauncher.add_app_launcher_args(parser)
args_cli = parser.parse_args()

app_launcher = AppLauncher(args_cli)
simulation_app = app_launcher.app

########################################

import torch
import gymnasium as gym
from omni.isaac.lab_tasks.utils import parse_env_cfg

env_cfg = parse_env_cfg(
    args_cli.task,
    device= args_cli.device,
    num_envs=args_cli.num_envs,
    use_fabric=not args_cli.disable_fabric,
)

# adjust camera resolution and pose
env_cfg.viewer.resolution = (640, 480)
env_cfg.viewer.eye = (1.0, 1.0, 1.0)
env_cfg.viewer.lookat = (0.0, 0.0, 0.0)
# create isaac-env instance
# set render mode to rgb_array to obtain images on render calls
env = gym.make("Isaac-Lift-Cube-Franka-v0", cfg=env_cfg, render_mode="rgb_array")
# wrap for video recording
video_kwargs = {
    "video_folder": "videos/train",
    "step_trigger": lambda step: step % 1500 == 0,
    "video_length": 200,
}
env = gym.wrappers.RecordVideo(env, **video_kwargs)

env.reset()
for i in range(200):
    action = env.action_space.sample()
    action = torch.tensor(action).float()
    obs, reward, done, trunc, info = env.step(action)

env.close()

Run the script above with python test2.py --headless --enable_cameras --task Isaac-Lift-Cube-Franka-v0

Error:

Moviepy - Building video /home/arhan/projects/clean-up-the-kitchen/videos/train/rl-video-step-0.mp4.
Moviepy - Writing video /home/arhan/projects/clean-up-the-kitchen/videos/train/rl-video-step-0.mp4

Traceback (most recent call last):
  File "/home/arhan/projects/clean-up-the-kitchen/test2.py", line 53, in <module>
    obs, reward, done, trunc, info = env.step(action)
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/gymnasium/wrappers/record_video.py", line 187, in step
    self.close_video_recorder()
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/gymnasium/wrappers/record_video.py", line 204, in close_video_recorder
    self.video_recorder.close()
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/gymnasium/wrappers/monitoring/video_recorder.py", line 157, in close
    clip.write_videofile(self.path, logger=moviepy_logger)
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/moviepy/decorators.py", line 54, in requires_duration
    return f(clip, *a, **k)
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/moviepy/decorators.py", line 135, in use_clip_fps_by_default
    return f(clip, *new_a, **new_kw)
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/moviepy/decorators.py", line 22, in convert_masks_to_RGB
    return f(clip, *a, **k)
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/moviepy/video/VideoClip.py", line 300, in write_videofile
    ffmpeg_write_video(self, filename, fps, codec,
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/moviepy/video/io/ffmpeg_writer.py", line 213, in ffmpeg_write_video
    with FFMPEG_VideoWriter(filename, clip.size, fps, codec = codec,
  File "/home/arhan/micromamba/envs/isaaclab-pip/lib/python3.10/site-packages/moviepy/video/io/ffmpeg_writer.py", line 88, in __init__
    '-r', '%.02f' % fps,
TypeError: must be real number, not NoneType

System Info

• Commit: 2af9018dc4ca623dff7d5033d84c5d231ce7030b
• Isaac Sim Version: 4.1.0
• OS: Ubuntu 22.04.2
• GPU: NVIDIA GeForce RTX 3090 Ti
• CUDA: 12.4
• GPU Driver: 550.54.14

Checklist

• [X ] I have checked that there is no similar issue in the repo (required)
• [ ] I have checked that the issue is not in running Isaac Sim itself and is related to the repo

[arhanjain]

This seems to be a dependency issue with MoviePy. Not directly relevant to isaaclab!