4 replies to this topic

[olan]

Hi.. I've been assigned to make a VB game that should be shown in TV screen and must be shown on a layer on top of other video that already playing (its kinda like interactive quiz that you usually see in the Television, plus animation or movie)... I've been successful in making a form that loads and plays the movie, but when I tried to combine it with other video, the form doesnt show cuz it seems the whole form has alpha-channel on it so that the video renderer engine [my office use DeckLink, probably you've heard it] ignores the color information thus make the whole form turns invisible....

What I wanted to know is how to make (some part of) my Form come to visible , or probably there is a way to remove the Alpha-Channel information in some part that I wanted to show in the video renderer.. Please, any comment would be very appreciated...

Thanks in advance..

[Goz]

Well for one it sounds like the video is simply rendering over the top. Have you tried drawing the video first? I suspec the VB window won't draw with transparency though ... thus you are going to need to render the window and then copy that window to a texture and use either 3D Hardware to render the 2 over each other or write yourself a software 2D blend (Could be made pretty damned quick as a fixed blend).

[olan]

umm, actually the VB window does have "transparency information" so that when i drag it to other monitor that plays the video (which shows the female presenter of the show) the form doesnt showed up...

FYI, the on-air video machine (the thing that combines presenter video and any other videos) is using alpha information to determine which part should be shown and which part that shouldnt be rendered.. And since I cant get my form to be shown in the monitor, i assume theres alpha channel on it...

What I needed is (for now :mellow: ) to make the Quicktime Movie only -- which i called using the VB form -- to be shown on top of the presenter video, just like the common interactive quiz in tv i've mentioned before..

I heard that we can use Direct Draw capability to draw/render a form/layer that has alpha-chanel that we can configure, izzat true??

[Goz]

olan said:

umm, actually the VB window does have "transparency information" so that when i drag it to other monitor that plays the video (which shows the female presenter of the show) the form doesnt showed up...

FYI, the on-air video machine (the thing that combines presenter video and any other videos) is using alpha information to determine which part should be shown and which part that shouldnt be rendered.. And since I cant get my form to be shown in the monitor, i assume theres alpha channel on it...

I know i may be wrong .. but i think you assume wrongly. Just because something doesn't draw doesn't mean there is alpha involved at all. If you draw something over the top of something else the original thing goes invisible ...

Have you got the VB window set to "top most"? Try that and then drag it over .. it should be able to remain in front of the video when you drag it across.

[olan]

Alright...Thanks for your suggestions...

I suppose i'm assuming too much with my little knowledge... :)
I havent set my VB window to "top most" cuz i dont know how to do it, yet..:huh:
And I still havent get to know the technology behind the video renderer machine that my office used...

But for sure if a Quicktime movie doesnt have alpha information at all, it would be rendered under another movie and doesnt showed anything....

When I tried using movie that has Alpha it shown up as I expected...

So the problem probably lays on Quicktime technology, I suppose..? Oh my, I'm assuming things again :o
Hehehe... :blush: