Использование MoviePy, который может импортировать видео с определенным c разрешением:
from moviepy.editor import VideoFileClip, concatenate_videoclips
filenames = ["vid1.mp4", "vid2.mp4"] # You could generate this from os.listdir or similar
clips = []
for file in filenames:
clips.append(VideoFileClip(file, target_resolution=(1920, 1080))
final_clip = concatenate_videoclips(clips) # method="chain" by default. This is fine because all clips are the same size
final_clip.write_videofile("out.mp4")