[Cin] possible alpha bug in processing

[Igor BEGHETTO]

I have done a build by git 20221117 where I changed line 104 in 
"virtualvconsole.C"
From: vrender->video_out->set_clear_color(clr_color, 0xff);
To:   vrender->video_out->set_clear_color(clr_color, 0x00);

1. I opened old projects to see how they behaved. It seems good.
2. I tested Open EDL feature using EDL_Files.zip by RafaMar in 
(ManrisBT0000558) as a sequence on the top of my project. It seems to 
work good.
3. Test with Mixer Viewer as shown in Tutorial "Cinelerra GG: Multi Cam 
editing (with Proxy)" https://www.youtube.com/watch?v=49EExsRsjlY . It 
seems good.

4. BUT I noticed a problem when the Nested clip with fade In is pasted 
in the Master project; however, that is there also without the mod.
My test file and screenshot in the compressed file to the link
https://transfer.sh/vURPjc/Test_AlphaChannelUsingFadeOnNested__Cin_2022117_and_0x00.tar.gz

The project uses the same Title effect for the Nested Clip as for the V3 
Video track. In the timeline there are three markers (labels). When the 
Insertion Point (the cursor) is pointing on the 2nd marker, the two  
texts should have the same white colour. Unforunately this does not 
happen. It is weird, but I think it would be useful to keep this mod.
It is possible to have the right behaviour in the Nested clip by 
changing the "Overaly mode", in the V4 video track, from Normal to 
PorteDuff...->SrcOver.
Finally, I wouldn't close the ticket "0000558: Problem with alpha 
channel when using a nested or reference EDL" 
(https://www.cinelerra-gg.org/bugtracker/view.php?id=558) because, in my 
opinion, it is not completely solved. We could add a note about. Thanks!

About "... IgorBeg were able to see that the correction fixes render 
using PNG, EXR, and TGA", I don't know what you are referring to. I 
haven't tested anything about. Sorry.

IgorBeg


Il 19/11/2022 23:29, Phyllis Smith ha scritto:
> As IgorBeghetto recommended, I checked into GIT the change of 0xff to 
> 0x00 in virtualvconsole.C as Andrew provided in his patch " 
> 0001-background-clear-in-vconsole-must-be-set-to-0.patch". It will be 
> easy to undo if Igor and his computer, Charlie, find a problem with 
> it.  (Actually I never figured out how to back something out of GIT, I 
> just add back the original).
>
> Good find by Goat and glad Andrea and IgorBeghetto were able to see 
> that the correction fixes render using PNG, EXR, and TGA.  (I still 
> wonder what "Goat" stands for?).