關鍵幀有 I 幀、P 幀、B 幀
我們關注的是 I 幀,因為 I 幀少,P 幀和 B 幀太太多了
使用 pyav 獲取 I 幀,可以用下面的程式碼:
樣例程式碼:
import av
import av.datasets
content = av.datasets.curated("pexels/time-lapse-video-of-night-sky-857195.mp4")
with av.open(content) as container:
# Signal that we only want to look at keyframes.
stream = container.streams.video[0]
stream.codec_context.skip_frame = "NONKEY"
for frame in container.decode(stream):
print(frame)
# We use `frame.pts` as `frame.index` won't make must sense with the `skip_frame`.
frame.to_image().save(
"night-sky.{:04d}.jpg".format(frame.pts),
quality=80,
)