inconsistant behavior , depending on CPU GPU ( 32 or 8 ) bit used

fan-boy wrote on 4/3/2019, 4:28 PM

inconsistant behavior in Vegas , depending on
CPU GPU ,with ( 32 or 8 ) bit is used .

Mask Generator Invert functionality .
tested using Generated Media
Checker Board .
Check the Invert box , then turn
Mask Generator On\Off to toggle .

.............................................…....works ?

CPU , 32 bit , gamma 2.222 No ( RGB image portion becomes Solid White )

CPU , 8 bit , gamma 2.222       Yes
GPU , 32 bit , gamma 2.222      Yes
GPU , 8 bit , gamma 2.222       Yes

Next , when Alpha channel is forced to Solid Black ,
using FX Channel Blend .
The RGB image portion either remains the same
or becomes Solid Black .
using "Source Alpha" Blend mode , with just 1 Track .

CPU , 32 bit gamma 2.222 RGB portion is still visible
GPU , 32 bit gamma 2.222 RGB portion is still visible

CPU , 8 bit gamma 2.222 RGB portion has become Solid Black
GPU , 8 bit gamma 2.222 RGB portion has become Solid Black

i am inclined to believe the correct operation should be :
when Alpha Channel is Solid White , the Full RGB should be visible .
when Alpha Channel is Solid Black , the Full RGB should become Solid Black .
( "Source Alpha" blend mode is a kind of "Self induced" mask multiply )

From the above , it appears that these 4 out comes occur :

CPU 32 bit setup , does NOT function correctly .

CPU 8 bit functions correctly .
GPU 8 bit functions correctly .

GPU 32 bit works with Mask Generator , but NOT with Solid Black Alpha Channel .

Becuase CPU GPU 8 bit always work , this will go Un-noticed in Movie Studio .
( Movie Sudio only supports 8 bit )

Comments

fr0sty wrote on 4/3/2019, 11:21 PM

what do you mean by solid black alpha channel? Alpha defines transparency.

Marco. wrote on 4/4/2019, 4:18 AM

@fan-boy
I can repro the first issue in float point mode and with GPU accelaration turned off.

Don't know what you mean in that second case with alpha channel to be forced to solid black. Could you share a project file for this one?

fan-boy wrote on 4/4/2019, 12:39 PM

@fr0sty

@Marco.

yes , I did a project that uses Solid Black alpha channel , and I have found out , that project is only possible because of the different operation of GPU 32 bit mode . That project does NOT work when using 8 bit mode .

I had just posted a Vegas Tutorial "Fill Alpha channel with any ( image or video )" . Using GPU 32 bit .

later , by chance , I had Vegas in CPU 32 bit mode . i loaded that project just to see it , and it didn't work ! what ! Baffled at first . I realized i had gone back to CPU mode 32 bit . That's when i tinked with CPU GPU 32 bit ,8 bit combinations , with the results as shown above ..

Summary of the 3 tracks in that project :

Track 3 has the Black\White Mask stuffed into the alpha channel .

Track 2 is Generated Media Solid Black , aka ( RGB is solid black , it's alpha is solid white )

Track 1 , RBG is the original source image , while the alpha channel has been forced to Solid Black using FX Channel Blend . ( Track 1 is NOT possible to make , using 8 bit mode )

fan-boy wrote on 4/5/2019, 2:12 PM

I made a revised project of Tutorial "Fill alpha channel with any ( image or video )" . The revision works with 8 bit color , as it avoids using Solid Black alpha channel . There is a twist to making this revised project . It was interesting to write , could be interesting to read . 32 bit and 8 bit project settings continue to operate differently as noted above . For now , just need to Avoid those situations when using 32 bit color project settings ( I have no idea how deep an issue this could become ) . Just more bugs handed down from SF\Wisconsin\Sony .