您可以控制 Quartz Composer 中播放视频剪辑的速度吗？
有没有办法控制视频播放的速度？ 我对一种通过帧混合减慢速度的方法特别感兴趣，就像 Final Cut Pro 中的功能一样。
Is there a way to manipulate the speed of the video playback? I'm especially interested in a way to slow down with frame blending, exactly like the function in Final Cut Pro.
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目前无法使用内置的
Movie Loader补丁进行帧混合。不过，您可以任意控制播放头。
Movie Loader补丁，并设置Movie Location。广告牌。 电影应以正常速度播放。Timebase，然后选择External。 这为Movie Loader补丁提供了Patch Time输入，并将其冻结在第一帧。Patch Time输入的值是Movie Loader应渲染的时间偏移量（以秒为单位）。Patch Time补丁，并将其输出连接到Movie Loader的Patch Time输入。 电影应该再次以正常速度播放。现在到了有趣的部分：
数学表达式补丁并输入t/2作为方程。Patch Time补丁连接到Mathematical Expression的输入，并将Mathematical Expression的输出连接到Patch TimeMovie Loader补丁的 code> 输入 --- 电影现在以一半速度播放。您可以更改方程式来更改播放速率 ---
t/3将以 1/3 速度播放，t*2将以双倍速度播放，依此类推。但是，如果您在电影播放时更改播放速率方程，您会注意到播放头跳到新位置，而不是从上一次继续。
要解决此问题，您需要使用
Integrator补丁。Integrator，将Value设置为1，并将Integrator的输出连接到Movie Loader的Patch Time输入。 电影应该以正常速度从头开始播放。Integrator的Value更改为0.5。 影片应以半速播放，从当前位置继续播放。您甚至可以使用此技术向后播放电影（不过，根据您使用的编解码器，它可能会严重影响性能）。
Currently it's not possible to do frame-blending using the built-in
Movie Loaderpatch.You can arbitrarily control the playback head, though.
Movie Loaderpatch, and set theMovie Location.Billboard. The movie should play at normal speed.Timebase, and then selectExternal. This gives theMovie Loaderpatch aPatch Timeinput, and freezes it at the first frame.Patch Timeis the time offset, in seconds, at which theMovie Loadershould render.Patch Timepatch, and connect its output to theMovie Loader'sPatch Timeinput. The movie should again play at normal speed.Now comes the fun part:
Mathematical Expressionpatch and entert/2for the equation.Patch Timepatch to the input of theMathematical Expression, and the output of theMathematical Expressionto thePatch Timeinput of theMovie Loaderpatch --- the movie now plays at half speed.You can alter the equation to change the playback rate ---
t/3will play at 1/3 speed,t*2will play at double speed, and so forth.However, if you change the playback rate equation while the movie's playing, you'll notice that the playback head jumps to a new position rather than continuing on from the previous time.
To solve this, you'll want to use the
Integratorpatch.Integrator, set theValueto1, and connect theIntegrator's output to theMovie Loader'sPatch Timeinput. The movie should play from the beginning at normal speed.Integrator'sValueto0.5. The movie should play at half speed, continuing from the current position.You can even play movies backwards using this technique (though, depending on what codec you use, it may severely impact performance).
v002 Movie Player（测试版） 作为内置 Movie Loader 补丁的替代品提供了
费率输入。 我已经得到了非常平滑的视频速度变化。（我添加了
Playhead Seconds输入；如果其他人觉得有用，我会发布它。）v002 Movie Player (Beta) as a replacement for the built-in Movie Loader patch provides a
Rateinput. I have gotten very smooth video speed changes with that.(I added the
Playhead Secondsinput; if anybody else would find that useful I'll post it.)插值应该可以帮助你。 Quartz Composer 中包含一个示例 (Interpolation Modes.qtz) 和一个入门教程 这里简短地提到了它（第5步）。
这篇 wiki 文章 也讨论了它并讨论了不同的类型。
注意：我实际上没有可以运行 QC 的 Mac，所以这只是我通过 Google 找到的内容，但听起来它应该能让您走上正确的道路。
Interpolation should be able to help you. There's an example included with Quartz Composer (Interpolation Modes.qtz) and a beginning tutorial here that breifly mentions it (step 5).
this wiki article also discusses it and talks about the different types.
Note: I don't actually have a Mac that can run QC, so this is just what I've been able to find through Google, but it sounds like it should get you on the right track.