video.py

import cv2
import imageio
import numpy as np


class VideoRecorder:
    def __init__(self,
                 root_dir,
                 render_size=256,
                 fps=20,
                 camera_id=0):
        if root_dir is not None:
            self.save_dir = root_dir / 'eval_video'
            self.save_dir.mkdir(exist_ok=True)
        else:
            self.save_dir = None

        self.render_size = render_size
        self.fps = fps
        self.frames = []
        self.camera_id = camera_id

    def init(self, env, enabled=True):
        self.frames = []
        self.enabled = self.save_dir is not None and enabled
        self.record(env)

    def record(self, env):
        if self.enabled:
            if hasattr(env, 'physics'):
                frame = env.physics.render(height=self.render_size,
                                           width=self.render_size,
                                           camera_id=self.camera_id)
            else:
                frame = env.render()
            self.frames.append(frame)

    def log_to_wandb(self):
        frames = np.transpose(np.array(self.frames), (0, 3, 1, 2))
        fps, skip = 6, 8
        wandb.log({
            'eval/video':
            wandb.Video(frames[::skip, :, ::2, ::2], fps=fps, format="gif")
        })

    def save(self, file_name):
        if self.enabled:
            path = self.save_dir / file_name
            imageio.mimsave(str(path), self.frames, fps=self.fps)