Fps=xx, ConvertFps=true VS ConvertFps(xx)

[xicudiz]

Hi all,I have two script

DirectShowSource("Videopath",fps=xx,convertfps=true)

And

DirectShowSource("Videopath")
ConvertFps(xx)

Is will give me same result?
Thank you.

[jagabo]

No, they will not.

DirectShow's convertfps will convert a variable frame rate video to constant frame rate by duplicating the longer frames. So a video with 3 frames, one with 1/25 second duration, one with 4/25 seconds duration, and a third with 1/25 seconds duration will return you 6 frames at 25 fps. The first encoded frame will appear once, the second encoded frame will appear 4 times, and the third will appear once.

If you don't use DirectShow's convertfps, you will get three frames from the video, then ConvertFPS() will stretch that out to six frames. The first frame will appear twice, the second frame will appear twice and the third frame will appear twice. And ConvertFPS will use frame blending for the intermediate frames.