Is there a way to automatically recognize media transparency?

smhontz wrote on 6/8/2004, 8:13 PM

Not matter what program I use (Cool 3D, PhotoShop, Boris, BluffTitler) to create something with an alpha (transparent) channel, Vegas doesn't recognize it automatically. I ALWAYS have to go into the media properties and set it there. The explorer shows that the media is x32, not x24, so why do I have always have to tell Vegas that there is an alpha channel? Is there some setting somewhere I'm missing?

Comments

roger_74 wrote on 6/9/2004, 3:20 AM

Here's a script you can try. It allows you to set the alpha channel for selected events.

//ChangeAlphaChannel.js by Roger Magnusson (roger_74 at home dot se)
import Sony.Vegas; // SonicFoundry.Vegas for Vegas 4

var ChangeAlphaTo : VideoAlphaType = VideoAlphaType.Premultiplied; //Set this to the type you want
/*
VideoAlphaType.Undefined
VideoAlphaType.None
VideoAlphaType.Straight
VideoAlphaType.Premultiplied
VideoAlphaType.PremultipliedDirty
*/

for (var currentTrack : Track in Vegas.Project.Tracks)
{
  if (currentTrack.IsVideo() == true)
  {
    for (var currentEvent : VideoEvent in currentTrack.Events)
    {
      if (currentEvent.Selected == true)
      {
        VideoStream(new Media(currentEvent.ActiveTake.MediaPath).Streams.GetItemByMediaType(currentEvent.MediaType, currentEvent.ActiveTake.StreamIndex)).AlphaChannel = ChangeAlphaTo;
      }
    }
  }
}

smhontz wrote on 6/9/2004, 5:39 AM

Thanks for the script, but I was wondering why it doesn't AUTOMATICALLY recognize the alpha channel. I've seen SPOT and others mention in other threads about adding media to the time line and "it automatically recognizes the alpha channel" but I've never seen that happen.

So, my question is: under what circumstances WILL it recognize the alpha channel and is there a setting I'm missing?

roger_74 wrote on 6/9/2004, 6:34 AM

You could try setting the stream properties and saving it, but then I guess it will always use that setting regardless if there is an alpha channel or not.

Jsnkc wrote on 6/9/2004, 8:41 AM

I've only imported Photoshop files that have transparencies and I've never had vegas not see them, except for the few times I accidentally save them out as CMYK and not RGB.

SonyEPM wrote on 6/9/2004, 9:41 AM

What format are the files you are rendering in your other apps (QT, AVI etc, including codec)?

smhontz wrote on 6/9/2004, 11:29 AM

1. From LiveType on the Mac - QT, animation codec.
2. From Ulead Cool 3d, uncompressed .avi (32 bits)
3. From BluffTitler - uncompressed avi with alpha
4. From Boris - Export Movie File, AVI-VFW, Full Frames (Uncompressed), Alpha: Straight.

I was wrong about Photoshop - both the .psd and png formats seem to work ok (i.e., Vegas recognizes the transparency). But all the other examples above I always have to change the media properties to see the alpha channel.