[Cin] possible alpha bug in processing

[Phyllis Smith]

Updated BT #558 based on IgorBeghetto's testing and still at least 1
problem left.
Sorry about the confusion of the render with PNG, EXR, and TGA which I
"think" was already working correctly and Andrew confirmed.  That is what
this thread started out with and somehow morphed into BT 558 partial fix.



On Sun, Nov 20, 2022 at 7:51 AM Igor BEGHETTO via Cin <
cin at lists.cinelerra-gg.org> wrote:

> 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?).
> --
> Cin mailing list
> Cin at lists.cinelerra-gg.org
> https://lists.cinelerra-gg.org/mailman/listinfo/cin
>
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