python枕头增加gif文件大小x10

Question

我想更改动画gif的持续时间。

使用Python Pil提取帧，然后创建具有不同持续时间的新gif。

from PIL import Image, ImageDraw
import os

def extractFrames(inGif):
    frame = Image.open(inGif)
    frames = []
    nframes = 0
    while frame:
        frames.append(frame)
        nframes += 1
        try:
            frame.seek( nframes )
        except EOFError:
            break;
    return frames, nframes

frames, nframes = extractFrames('1.gif')
interval = 100
# In documentation says duration is interval time, but it is total time.
total_duration = nframes*interval
# Save into a GIF file that loops forever
frames[0].save('1_1.gif', format='GIF', append_images=frames[1:], save_all=True, duration=total_duration, loop=0)

但是文件大小约为原始图像的10倍。

我不明白为什么会这样并且可以预防吗？

我还尝试使用Exiftool仅更改元数据，但这对我也不起作用：

exiftool -overwrite_original -XMP-xmpDM:Duration={Scale="s",Value=14} 1.gif
Warning: Improperly formed structure for XMP-xmpDM:Duration
Warning: Improperly formed structure for XMP-xmpDM:Duration
Nothing to do.