user9242: There is a 60 FPS video clip, with 1 Second total duration (So it has 60 frames, each 1/60s duration)
I make it 2× faster. So it's has a 0.5s total duration. How about frames? 
How many frames are in my 0.5s video? 60 frames each 1/120s, or 30 each 1/60s?
In a tutorial the author says: "I recorded those images at 60 frames a second and time remapped the video to about 2-3x getting about 120-180 frames to work with."
I just wonder if speeding up (in this case time remapping) the video clip for 2x will result in removal of half of the frames, how the tutorial is saying it give you 120 frames to work with? 

user3908: In the simplest case, half the frames -- every second frame, or all the even (or odd) numbered original frames -- are just gone, discarded. The frame rate of the resulting video does not change, it's still 60 fps.
It's possible to create a video where each new frame is a blend of two original frames but this is unusual and often not effective. Or in a field-based system where each original frame is composed of two distinct half vertical resolution images, you can discard half the fields instead of half the frames. But still, the result will be 60 fps.  
If you were working in a 60 fps environment and imported a 30 fps clip, you could effectively double the frame rate of the original clip, but that isn't what you asked about.

9242: <p>There is a 60 FPS video clip, with 1 Second total duration (So it has 60 frames, each 1/60s duration)</p>

<p>I make it 2× faster. So it's has a 0.5s total duration. How about frames? </p>

<p>How many frames are in my 0.5s video? <strong>60 frames each 1/120s, or 30 each 1/60s?</strong></p>

<p>In a tutorial the author says: "I recorded those images at 60 frames a second and time remapped the video to about 2-3x getting about 120-180 frames to work with."</p>

<p>I just wonder if speeding up (in this case time remapping) the video clip for 2x will result in removal of half of the frames, how the tutorial is saying it give you 120 frames to work with? </p>
 3908: <p>In the simplest case, half the frames -- every second frame, or all the even (or odd) numbered original frames -- are just gone, discarded. The frame rate of the resulting video does not change, it's still 60 fps.</p>

<p>It's possible to create a video where each new frame is a blend of two original frames but this is unusual and often not effective. Or in a field-based system where each original frame is composed of two distinct half vertical resolution images, you can discard half the fields instead of half the frames. But still, the result will be 60 fps.  </p>

<p>If you were working in a 60 fps environment and imported a 30 fps clip, you could effectively double the frame rate of the original clip, but that isn't what you asked about.</p>
