In Windows 7 videos are pixelate when desktop composition mode is turned on unless they're display using Direct3D or other good renderer. Is possible to made video preview with good renderer?
That may be down to the video codecs, or possibly video drivers, you have installed.
Does Windows Media Player do the same thing?
This happens on many win7 systems (I worked with 32bit and 64bit) and some people report that also (not in opus viewer but lot of players). Some players in early days even forced disabling desktop composition (likve VLC does) for proper display. Unfortunatelly - desktop compositions is what helps viewing movies (no tearing or screen bliking because of forced vertical sync of system in that mode).
Few links that I found in few seconds:
forum.videohelp.com/threads/3276 ... t-renderer
(and don't worry that he is talking about Aero - it's "desktop composition" fault, not Aero theme itself).
superuser.com/questions/22824/vl ... d-playback
forum.videolan.org/viewtopic.php?f=14&t=64428
(look at one answer - "Edit: Also, going to [Tools > Preferences > Video], and setting the output to OpenGL is a good fix for this problem, without causing you to lose Windows Aero.")
Is more like this ones but they may be confusing sometimes because of bad answers (like "that's new/old drivers fault" etc. - basically all that answers that contains "try" word instead of experience).
I discover that default renderer in Windows is not what shows movies good when desktop composition is on. I have Direct3D renderer in my PotPlayer and everything works great. I also used GOM player with proper settings and everything works great. But when I revert to basic renderers - I always get pixelate video (not only in Opus). So, my question is - can Opus have more complex renderer for modern systems?
I've not had a chance to look into this in detail, but you can use alternative movie viewers by disabling the Movie plugin in Opus, so that it falls back on the Windows Media Player preview handler.
We can also use other preview handlers (or ActiveX controls if properly registered) in the viewer.
So there may already be a video player which works in Opus and does what you want.
Failing that, there's a plugin API if someone wants to write one, or we may look into this when time permits.
Disabling movie player and enabling activex+preview+office+web helps, but I don't really want to enabling activex or windows media player. Is it safe to enable activex?
ActiveX is just a way of talking to plugin DLLs; it's not inherently unsafe. (The way it was used in early versions of IE was unsafe, but that's something else.)
I just want to be 100% sure - there is no way to run dangerous code using activex in DO? Some html preview with unsafe code that browsers can handle but DO can't etc?
The only code that will run is code you have already installed on your machine.
If you've installed something that included a dangerous ActiveX control registered for the video filetypes, then of course you could run dangerous code. The same as if you've installed something that included a dangerous right-click context menu shell extension, video codec, preview handler, viewer plugin or any other type of plugin.
IE is used as a viewer for some filetypes, and its behaviour is obviously up to Microsoft rather than us, but we flag all files as being in the internet domain so it should be as secure as viewing a file in IE itself, from the web. IE would not be used for video files unless you went out of your way to configure that in Opus, though.