Originally Posted by Tom Frank
I tried your method, but it comes out very jerky compared to the method I gave. It looks to me like the toggles in the frame Rate Conversion box are all mutually exclusive (Radio Buttons!). If I set the frame rate to 300 fps there and then select decimate by 10, only the decimate by 10 toggle takes effect. The video plays back every 10th frame at what ever frame rate the source frame rate is toggle to. If I set the frame rate to 300 fps setting last in that block, I get a video that plays back at 300 fps, but with each frame duplicated 10 times, so it still looks like the original playing back at 30 fps. The only way I can get a video to play back all frames smoothly at an accelerated rate is to just set the Source Frame rate to 300 fps and leave the other toggle set to "process all frames".
Sorry I wasn't clear -- I was going from memory -- but I set the SOURCE frame rate, the same as your method, but then set the Decimate By in the Conversion box to remove frames, so the output video ends up being 30 fps, not 300 fps, and it's 1/10th the file size. I saw this method recommended on a forum a few years ago, and it works well for me. If your computer can really process anything like 300 fps, then that would certainly be smoother than 30 fps, but mine won't, so your method looks choppier on my computer, apparently because of random numbers of playback dropped frames.