26 lines
778 B
Python
26 lines
778 B
Python
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import numpy as np
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def fadein(clip, duration, initial_color=None):
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"""
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Makes the clip progressively appear from some color (black by default),
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over ``duration`` seconds at the beginning of the clip. Can be used for
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masks too, where the initial color must be a number between 0 and 1.
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For cross-fading (progressive appearance or disappearance of a clip
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over another clip, see ``composition.crossfade``
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"""
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if initial_color is None:
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initial_color = 0 if clip.ismask else [0,0,0]
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initial_color = np.array(initial_color)
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def fl(gf, t):
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if t>=duration:
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return gf(t)
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else:
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fading = (1.0*t/duration)
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return fading*gf(t) + (1-fading)*initial_color
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return clip.fl(fl)
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