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Avec les filtres avisynth FadeOut / FadeOut2
FadeOut / FadeOut2
FadeOut(clip, int frames)
FadeOut2(clip, int frames)
FadeOut and FadeOut2 cause the video stream to fade linearly to black at the end. The sound track (if present) also fades linearly to silence. The fading affects only the last number-of-frames frames of the video. The last frame of the video becomes almost-but-not-quite black. An additional perfectly black frame is added at the end, thus increasing the total frame count by one.
FadeOut2 works similarly, except that two black frames are added at the end instead of one. The only purpose of this is to work around a bug in Windows Media Player. All the WMP versions that I've tested fail to play the last frame of an MPEG file--instead, they stop on the next-to-last frame when playback ends. This leaves an unsightly almost-but-not-quite-black frame showing on the screen when the movie ends if you use FadeOut. FadeOut2 avoids this problem.
FadeOut(clip,n) is just a shorthand for Dissolve(clip,Blackness(clip,n+1),n) (or n+2 instead of n+1 for FadeOut2). There is no corresponding FadeIn command, but you can get the same effect by reversing the arguments to Dissolve: Dissolve(Blackness(n+1,clip),clip,n).