In Lightworks, there's the selective color correction tool.
By moving the sliders like this you can select the shadows (luma slider) and desaturate them:
By clicking "Reveal" you can see which parts of the image are going to be changed.
With much thanks to the guys at the Lightworks forum.
Source: Lightworks forum: Desaturate shadows
Ah! Okay, so apparently you now right-click on the clip and select "Speed.." from the context menu. The location of the mouse pointer when you right-click doesn't seem to matter. Not sure if the location of the current playback point still determines the stable point during the speed change.
Looks like you will need to transcode all clips with frame rates not matching the project's frame rate:
If the frame rate is of a clip is not compatible with your project, it
displays in red. You will be unable to import the clip into your
project. Clips with incompatible frame rates may be playable in a new
project set to the same frame rate as ...
Sometimes this will happen from a verity of reasons. Sometimes the clocks are different. A lot of time it comes down to manual re-syncing.
Pick 2 sync points for the Video and the same 2 points for the audio. Make sure they are as far away as possible. Now divide the duration in frames between the 2
V dur / A dur = ratio
Now you have the ratio you should ...
If you have a high-end i7 PC desktop, you probably have the infrastructure to set up a high-performance RAID that can handle your I/O bandwidth requirements. 10GB/min = 167MB/sec, which a really good 3.5" disk can almost deliver. If you stripe 2 such disks together, it's an easy target to hit (as long as there's no other I/O contention). So, have your ...
The limitation is certainly the disk I/O, which at 10GB/min is outside the capabilities of all but very high-end disk subsystems.
It's generally true that you should work at the highest bit rate and bit depth your system is capable of so you have the headroom for processing, but your system simply isn't capable of working at the rates your asking of it.
Don't do sync work with the MP4s/H264 codec. Use proper codecs (ProRes or DNxHD).
Work with .wav or .aif audio files.
Keep an eye on your audio file sample rates.
Lightworks is much less forgiving to small errors than other programs are. Be super precise.
Get a better computer. The fact that the audio sounds fine in other apps means it was recorded fine, and the file represents the audio correctly. When you open it in your editor though, that's a much more complex operation than simply playing the video in an optimized player. So, I think this is a performance issue. I've had this problem myself with cheaper ...