im very new to hitfilm right now but when i speed up the video the video will play the video like normal then after about 5 seconds it just goes black, i can still hear the audio but otherwise there is nothing.
Hitfilm 3 does not speed up audio when it speeds up video. What's happening is you're speeding up the clip and it's turning black when you hit the end of the video. Because there aren't any more frames.
To speed up your audio you'll have to use an external audio editor. Audacity will do it, and Audacity is free.
The best way to use the Speed effect is to place the footage you want to speed up or slow down in it's own composite shot. Set the length of the composite shot to the duration you want the video to end up (5 seconds if you're speeding up a 10 second clip to 200%. 20 seconds if you're slowing down a 10 second clip to 50%), then embed the composite in your main shot and add the speed effect to the embedded comp.
ok thanks that really helped