How to Use Speed effect and why is it so slow?

Hey everyone, I am looking at getting into some more stylistic B-roll with some more speed ramping. However I am having trouble understanding how the speed effect works as well as I was wondering if there is a fix to it being so slow :)

 

Joseph Spratt

Comments

  • @fallcrom If i remember correctly, the speed effect is quite intensive. If you have a low end system (please provide your specs!) then it will run slow in the viewer.

    I don't know much about the speed effect, but I do know that it is used to change the speed of the clip it is added to.

  • Triem23Triem23 Moderator

    @fallcrom as Ben says, the Speed effect is resource intensive. Both your hardware and the type of video file used will affect performance. Mp4 would benefit from being transcoded to ProRes (Mac) or Cineform (Win) before import to Hitfilm. 

    @TheBenNorris let me tag you in for this bit. 

    The Speed effect in Hitfilm is kind of odd and unintuitive and is best used only for ramping. Fallcrom, I'll talk about other ways to deal with playback speed in a bit.

    First - and this is very important - Hitfilm "conforms" footage when it's added to the timeline. Let's say your footage is 60 fps and you add it to a 24fps timeline. At this point the start and end frames are defined and the footage is converted to "100% speed at 24fps." This means the timeline now has a "datablock" of a defined set of frames at 24fps. The rest of the frames are discarded. 

    The Speed effect applies AFTER CONFORMING. This means if you put a 60 fps clip on a 24fps timeline then apply a Speed Effect to make slow mo, it won't look right. The Speed effect is working only with the 24 frames per second defined in the datablock. The rest of the frames are "gone." 

    So, let's assume you've done something with the speed effect, and you want to trim the end of the clip... If you trim the end of the clip you have shortened the datablock, which changes the frames fed to the Speed effect, which will probably screw up your effect. 

    This means any clip with a Speed effect on it pretty much needs to be in its own embedded Comp, so that you can trim the embedded comp without changing the frame data being fed to the Speed effect. On the other hand the embedded comp can be pre-rendered to improve playback performance. 

    As I said, the Speed effect is odd and unintuitive.

    Ben, that ends what I tagged you in for, but you might want to skim the rest of this post anyway. 

    Fallcrom, the other two ways to deal with Speed are the Rate Stretch tool and the Clip's Properties.

    Rate stretch lets you grab the edge of the clip and drag it. The clip is altered to fit the new duration. This is not ramping (it's a constant speed), and this is applied (like the Speed effect) AFTER the source video is conformed once again a 60 fps clip on a 24 fps timeline and rate stretched is stretching the 24 conformed frames. Your slow mo won't look right.

    So, what do we do for smooth slow motion? We right click a clip in the media bin and select properties. Look for Frames per Second and uncheck "from file." Now if we take our 60 fps clip and change it to 24fps and drop it on the timeline we have slow motion. As the footage has been assigned a new frame rate before going on the timeline the "24fps" clip keeps all the frames on a 24fps timeline rather than "throw away" frames when a 60fps clip is conformed to 24fps.

  • Why cant we just slow down or speed up the footage like in premiere....that is way more intuitive 

  • It's not just Premiere. Others like Vegas and Resolve are just as simple and intuitive. Heck, maybe all others.

    The squeaky wheel get the grease. Maybe at some point FxHome will address this.

    Lack of features in an app is less of an issue, IMO, than features that just don't work right. Can you do it. Heck yes. Do you want to? To each his/her own. Is a feature as easy to use as some other app? So what. It should not piss you off to try use it. I would also put the timeline zoom in this same category (piss you off). To each his/her own.

  • @NormanPCN as I'm sure you have been told many times, we are a relatively small team that has to prioritize certain features and improvements. Both of these issues are on our radar but unfortunately do not take priority over our other work. If you really do desire these specific features then the best place to talk about it is the wishlist: despite it's chaotic nature I read every new post on there and relay it to relevant people.

  • I use the speed effect and okay, it is a bit weird to my liking but if you put it on a composite shot layer,  You want to add two points being at like 10 speed then in the middle you want that to be normal or 0.8, go in the value graphs and then mess around creating a U shape and you will have to work around it, I have used it in my work, it is a pain but it does create the best effects when pulled off correctly

  • Triem23Triem23 Moderator

    Oh, the TL/DR answer is "put the speed effected clip into an embedded comp shot and edit the comp. 

  • My question is, does the "speed and duration" tool work any better than the speed effect itself? Does it preserve the original frames of the video, or are they gone the moment you put them into the composite shot?

  • @ScottyBros

    It basically works the same. Different UI. Speed does do frame blending for resampling. Speed/Duration only does drop/duplicate.

    If by "preserve original frames" you mean placing a media file with a framerate above that of the timeline rate and then change the speed and in certain scenarios all original frames are used, then no. Hitfilm conforms media first and then after that other things like effects and frame rate resampling operate. So 60p media on a 30p timeline initially has half the frames thrown away before other things happen (like framerate resampling).

    If this is not what you mean then please be specific.

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