In vlc there are some video effects which I cannot find them in libvlc, when I open a video in vlc I can go to "Tools->Effect and Filters ->Video Effects" and then there are many video effects which I can use , such as negating the color or denoisers or posterizing,etc.
I can set some of them by "libvlc video_set_adjust_float", it can set contrast, brightness and some other options.
Is there any way to use these options in libvlc? (I want to use some of these effects in my program written by libvlc).
There is no API in LibVLC to use any of the other filters.
You can, but it is totally not supported, use the same command-line switches for those filters and pass them to LibVLC in one of two ways, either: when you create your LibVLC instance via libvlc_new, or; when you create a media instance you can add some of those switches as options by using libvlc_media_add_option.
This approach has many drawbacks however. Apart from it not being supported, for some things you can only set the options this way once and never change them.