如何在 python 装饰库中设置 fps？

Question

package link : https://github.com/dmlc/decord

I am using decord to extract frames and it does a good job, by default it uses video fps. Lets say i need to extract frame at 0.2 fps.

example : i have a video at 48 seconds and its fps is 30. when i extract i get 1440 frames

But, I need to specify the fps like 0.2 so , the output should be 10 frames.

PS. In ffmpeg, we can specify the fps while extracting. I am asking in the same way.

My code:

from decord import VideoReader
from matplotlib import pyplot as plt

vr = VideoReader("nature.mp4")
vr._avg_fps = 0.2  ##Not worked
for i in range(len(vr)):
    frame = vr[i].asnumpy()
    plt.imsave(f'{name}_Frame_{i}.jpg',frame)

Help appreciated

Answer 1

maybe you can skip frame like this:

from decord import VideoReader
from matplotlib import pyplot as plt

vr = VideoReader("nature.mp4")
avg_fps = 0.2
for i in range(0, 1500, int(30/min(30,avg_fps))):
    frame = vr[i].asnumpy()
    plt.imsave(f'{name}_Frame_{i}.jpg',frame)