Dalmazzo

I am trying to compose something using pictures with alpha. I am putting all together using jit.gl.videoplanes with alpha_blend. But I need to incorporate a video with an animal walking, the animal more and less is white (but it looks real not only white) and the background is totally black. Therefore, I need to add alpha channel to the background but after some hours I don’t get it. Anybody have a solution for this kind of compositions? 

I am trying to do a video with an animal without alpha and the background with only alpha channel.

The second question is what kind of video compression use alpha channel? 

Thanks a lot for the help, I am running against time (like always).

Hi everybody
I am trying to compose something using pictures with alpha. I am putting all together using jit.gl.videoplanes with alpha_blend. But I need to incorporate a video with an animal walking, the animal more and less is white (but it looks real not only white) and the background is totally black. Therefore, I need to add alpha channel to the background but after some hours I don’t get it. Anybody have a solution for this kind of compositions? 
I am trying to do a video with an animal without alpha and the background with only alpha channel.
The second question is what kind of video compression use alpha channel? 
Thanks a lot for the help, I am running against time (like always).


alpha-chanel-on-video-with-black-background

sounds like you need to do a basic 'add' composite. literally add 

your animal to the background video using either jit.op or jit.slab 

before it's displayed on your videoplane. look at the jit.gl.slab-op 

example in examples/jitter-examples/render/slab

popular video codecs that take an alpha channel are the Animation 

On May 21, 2008, at 3:08 PM, David Dalmazzo wrote:

> I am trying to compose something using pictures with alpha. I am 

> putting all together using jit.gl.videoplanes with alpha_blend. But 

> I need to incorporate a video with an animal walking, the animal 

> more and less is white (but it looks real not only white) and the 

> background is totally black. Therefore, I need to add alpha channel 

> to the background but after some hours I don’t get it. 

> Anybody have a solution for this kind of compositions?

> I am trying to do a video with an animal without alpha and the 

> The second question is what kind of video compression use alpha 

> Thanks a lot for the help, I am running against time (like always).

sounds like you need to do a basic 'add' composite.  literally add  
your animal to the background video using either jit.op or jit.slab  
before it's displayed on your videoplane.  look at the jit.gl.slab-op  
example in examples/jitter-examples/render/slab

popular video codecs that take an alpha channel are the Animation  
codec and Photo-Jpeg (I think)

>
> Hi everybody
> I am trying to compose something using pictures with alpha. I am  
> putting all together using jit.gl.videoplanes with alpha_blend. But  
> I need to incorporate a video with an animal walking, the animal  
> more and less is white (but it looks real not only white) and the  
> background is totally black. Therefore, I need to add alpha channel  
> to the background but after some hours I don’t get it.  
> Anybody have a solution for this kind of compositions?
> I am trying to do a video with an animal without alpha and the  
> background with only alpha channel.
> The second question is what kind of video compression use alpha  
> channel?
> Thanks a lot for the help, I am running against time (like always).


sorry - I take that back about Photo-Jpeg codec. It won't support an 

alpha channel if you're rendering out of something life After 

Effects. But don't forget you can make your own alpha channel in 

On May 22, 2008, at 12:04 AM, Ed Purver wrote:

> sounds like you need to do a basic 'add' composite. literally add 

> your animal to the background video using either jit.op or jit.slab 

> before it's displayed on your videoplane. look at the jit.gl.slab- 

> op example in examples/jitter-examples/render/slab

> popular video codecs that take an alpha channel are the Animation 

> On May 21, 2008, at 3:08 PM, David Dalmazzo wrote:

>> I am trying to compose something using pictures with alpha. I am 

>> putting all together using jit.gl.videoplanes with alpha_blend. 

>> But I need to incorporate a video with an animal walking, the 

>> animal more and less is white (but it looks real not only white) 

>> and the background is totally black. Therefore, I need to add 

>> alpha channel to the background but after some hours I don’t 

>> get it. Anybody have a solution for this kind of compositions?

>> I am trying to do a video with an animal without alpha and the 

>> The second question is what kind of video compression use alpha 

>> Thanks a lot for the help, I am running against time (like always).

sorry - I take that back about Photo-Jpeg codec.  It won't support an  
alpha channel if you're rendering out of something life After  
Effects.  But don't forget you can make your own alpha channel in  
jitter, using jit.unpack / jit.pack.

> sounds like you need to do a basic 'add' composite.  literally add  
> your animal to the background video using either jit.op or jit.slab  
> before it's displayed on your videoplane.  look at the jit.gl.slab- 
> op example in examples/jitter-examples/render/slab
>
> popular video codecs that take an alpha channel are the Animation  
> codec and Photo-Jpeg (I think)
>
> On May 21, 2008, at 3:08 PM, David Dalmazzo wrote:
>
>>
>> Hi everybody
>> I am trying to compose something using pictures with alpha. I am  
>> putting all together using jit.gl.videoplanes with alpha_blend.  
>> But I need to incorporate a video with an animal walking, the  
>> animal more and less is white (but it looks real not only white)  
>> and the background is totally black. Therefore, I need to add  
>> alpha channel to the background but after some hours I don’t  
>> get it. Anybody have a solution for this kind of compositions?
>> I am trying to do a video with an animal without alpha and the  
>> background with only alpha channel.
>> The second question is what kind of video compression use alpha  
>> channel?
>> Thanks a lot for the help, I am running against time (like always).
>


Animation codec is brilliant for wanting Alpha channel to work properly inside of Jitter. I'm kind of surprised I had to search a lot to find that out, but now I shout it from the rooftops: Use Animation! If you want functional-alpha in your QT movies coming into jit.qt.movie!

(Maybe that's obvious to everyone else, and that's why no one's mentioning it...)

Alpha Chanel on Video with black background