Please Help with transparent Media AVIs!

Grazie wrote on 6/9/2003, 9:12 AM
Okay - I've created a png - put it onto track1, with video on track2. I've animated the png so it slides in and then sldies out - excellent. Track2 video shows through - Great! I want to repeat this sliding png several times down the T/L. So I tohught, all I need to do is render this "Sliding Png" and use this new AVI sliding PNG and put it above other pieces of video on track 2. Problem is that it has lost its PNG transparency. It comletely obliterates the underlying video - Sliding PNG on a black background.

I'm presuming this has been done to death here, but now I'm up to this point in my learning mountain, of V4, please get back to me with what I need to do to create the transparency of the PNG. What format should I be render the Sliding PNG?

The other thing that is making me question what I'm doing is that I can use the RAW Sliding PNG, and the resultant Rendered Sliding PNG and video work fine.

TIA

Grazie

Comments

mikkie wrote on 6/9/2003, 9:47 AM
"Problem is that it has lost its PNG transparency."

Many (most?) avi codecs will not support the transparent (alpha) info present in the png image file format. Try playing with setting black or whatever background color to transparent, use chromakeying, masks etc... whichever works best and is easiest for you.
jetdv wrote on 6/9/2003, 9:52 AM
OR render to uncompressed AVI or MOV which DO support transparency.
VIDEOGRAM wrote on 6/9/2003, 10:27 AM
Hi Grazie,

I do this quite often, but I use AFTER EFFECTS to do it ... not quite shure that V4 can do this though.
I produce a .mov file in AE (with 32 bits "animation" codec) and import the resulted file in V4. It keys in as any other alpha channel file (.psd, .png, 32B .tga ...).

Gilles

Grazie wrote on 6/9/2003, 10:34 AM
Thanks Chaps!

Yeah - I took some of my own advice I dish out to others . . . I even aluded to this in my Post - I did a search in the archives - there it was!

mikkie - Neat idea! I'll see . . .

Ed - Yup uncompressed. Got the AVI back on to the T/L and made sure that the Media Properties were on "Straight". I worked fine. BUT BUT but .. . a 5 second clip (uncompressed coming in at 450mb for 11seconds!! WOW! Any way of reducing the size of this? I expect not, being uncompressed - eh?

TIA

Grazie
Grazie wrote on 6/9/2003, 11:17 AM
VIDEOGRAM - Sorry, your post just came in! - As I said above. V4 CAN do this, but at present it is a massive file - 450mb for 11seconds - phoorrrh - BIG!

If you have further options in which I could possibly REDUCE these file sizes all the better. The other thing - which I'm at last understanding - is the power of uncompressed avi format. Hmmm.... the penny is dropping.....

TIA

Grazie
SonyDennis wrote on 6/9/2003, 12:41 PM
Grazie:

You could also duplicate the event and the motion keyframes -- no need for an intermediate render.

///d@
Grazie wrote on 6/9/2003, 3:09 PM
Errr... Dennis, yes - been doing this since VF - excellent package! Sooo... what I was wanting to do was to create an event as a reusable AVI soo it wouldn't have to be re-render, and take more time - yeah?

"no need for an intermediate render." - yup looking to save time that's all.

Thanks for your feedback,

Grazie