Clip speed - more frames per second or removes frames?

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Hello community! Does anyone know whether the clip speed feature removes any frames or adds more frames per second? Thanks in advance..
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Jayne Davids

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Posted 10 months ago

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kayakman, Champion

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I believe that if you make clip play faster, frames are removed; make it play longer and frames are added
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Jayne Davids

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Thanks Kayakman
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Leif, Employee

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A project in Camtasia has a frame rate (currently fixed at 30 fps).  So we show 30 frames per second in the preview, and an exported video will have 30 fps.  So if you speed a clip up it we have to skip frames.  If you slow it down we have to duplicate frames.  For example, in the simplest case, where the source video is also a 30 fps video, if you change clip speed to be twice speed we have to discard every other frame.  For half speed, we duplicate every frame. 
On Camtasia MAC, if you slow down clip speed and the source video has more frames (say it was recorded at 60fps for example and you set clip speed to 1/2 speed), then all of the intermediate frames will be shown as well.  So the playback is more fluid as it plays back in slow motion.  In older versions of CMAC it did not behave this way and the frames were duplicated instead of the intermediate frames being shown.
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Jayne Davids

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Thank you so much for the clear explanation Leif.
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Leif, Employee

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No problem.  Hope it helped.
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Jayne Davids

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It certainly did thank you. A student raised the question in my Camtasia training course this week and I wanted to be certain of what actually happened before I shared the answer :)
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Leif, Employee

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For completeness, I should also mention what happens with audio.  In Camtasia MAC, the audio is time stretched to fit the new constraints.  So if clip speed is two times, the audio has to play back twice as fast so as not to skip any audio.  On Camtasia MAC, this is time stretched so the vocal sounds nearly the same, just talks way faster.  Same with 1/2 speed...the audio slows down to match without changing pitch (on Windows, it believe the audio changes pitch).  At some point, the audio becomes unintelligible, so the audio is muted and the waveform drawing on the clip is dimmed.  I don't have the actual numbers but it is something like you can stretch the clip up to 10x the length or to 1/4 of the length before the audio cuts out.
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Jayne Davids

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Thank you! Have a great weekend.
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davemillman

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@Leif, Thanks for that! your explanation should be in a tutorial or article somewhere! At least it's here now.
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gustavolugo

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I created a video at 4K at 60fps and when I imported to Camtasia it displayed as 24 fps. When I slowed the video down by .25% the software didnt include the missing frames. The final product was choppy and not smooth. please advise. I use a MBpro with camtasia V 3.1.5. I should add that camtasia noted my frames per second as 6
(Edited)
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kayakman, Champion

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I believe that when you slow down a clip with clip speed adjustment, that will throw away frames; so a 25% reduction should remove 75% of original frames?

when you imported the 4K 60 FPS cl;ip, had you set project settings to edit at 60 FPS?

otherwise, I don't know what MBpro is; are you using Camtasia for MAC?
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gustavolugo

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Thanks. I use a Macbook Pro. Camtasia V 3.1.5 doesnt allow me to set project setting on imported video. The only project setting that it allows me to change is the aspect ratio. Is there somewhere you can direct me? 
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kayakman, Champion

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I can't really help further; don't know or use MAC version; in Windows version Camtasia 2018.0.3., project settings let you set editing frame rate: 30 FPS or 60 FPS; a 60 FPS clip edited at 30 FPS may not play well

hopefully others more knowledgeable re MACs can help here
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Leif, Employee

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Camtasia 3 only supports 30fps editing.  Upgrade to Camtasia 2018 if you want to edit at 60fps.  I don't know what you mean by "camtasia noted my frames per second as 6".  I don't believe there is anywhere that Camtasia shows the fps except for exporting.  And there you can choose the fps to produce although it is capped at 30fps.