i have a problem with my contrast in my my monitor i can't see the video in progdvb but when i make a contrats in maximum i have better video i hope you make a correction and adjust progdvb contrast and make maximum contrast better old maximum contrast

If using a SS1 / premium card in hardware mode, contrast is adjustable from audio / video settings, as the hardware provides this.
But of course, no hardware DSP, no such controls...

In any other case, that's a matter of the codec's properties.

Depending on your VGA hardware and driver, there may be just another change, related to it's video overlay controls.

Basically, on CRT based computer screens, user contrast adjusting range is limited by intention, to provide a reliable readability for small fonts, by keeping the electron beams as sharp as possible.
A TV screen will lose it's sharpness partly if set to very high contrast and / or brightness, but due to the very limited resolution normally this does not matter there.

Another issue is the black level behaviour of computer screens, differnt from TV screens. For this, you may have to correct gamma controls for the Windows user surface (GUI), after contrast is set optimized for video. This is a matter of the VGA controls as well, and if wanting to control this in professional quality, the entry level for this is Adobe Gamma...

Keep in mind, contrast and brightness controls of screens do interact. So, in any case, check both more than once.

However, if talking technical issues, precision is a must.
You told, you can't see the video if (screen?) contrast not maximized.
But that would mean something completely different that if you could not enjoy, instead.