I followed all the steps in the over video of Twixtor. Nested the selected clips, created a new sequence, add the nested sequence as one video and applied twixtor after selection. I just changed the speed value to -100. As I wanted to slow down my original clip.
I render and play. Funny part is that it only applies to the first frame of the video.The remaining length of the video(that twixtor has been applied on as mentioned above) becomes black. I have tried to even lesser speed values and also increasing the clip size. But it does not seem to work.
Need help to understand incase I am doing anything wrong.
Negative speed is covered in our manual... have you found and read that?
Here is the relevant section:
Note on negative speed: A Speed% of -100.00 does not simply flip the original sequence so that it plays backwards starting at frame 0. Imagine the play head on your clip. If you are at the beginning of the clip and you tell the machine (Twixtor in this case) to start playing backward, then there's nothing before the clip starting position to play. That's why you will not see a result with a negative speed as the first keyframe. If you play the clip at 100% for a while, then put in a –30% keyframe (or other negative value) at the place where you want to start playing backward you will see proper results.
If you want to play backwards from the very beginning, and just slow it down, on the original clip (in your nested sequence, not where Twixtor is applied), use FCP's speed setting and set the clip IN FCP to play at -100%. Then use Twixtor to play at the appropriate slowed-down speed (not negative, because FCP is already doing that part for you).