Bug 458073

Summary: SVG files when rendering should be rendered for optimal viewing during every frame of the video, not simply used as an image after import
Product: [Applications] kdenlive Reporter: raibo.quadrofus
Component: Rendering & ExportAssignee: Jean-Baptiste Mardelle <jb>
Status: REPORTED ---    
Severity: normal CC: R.Clark.01
Priority: NOR    
Version First Reported In: git-master   
Target Milestone: ---   
Platform: Flatpak   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description raibo.quadrofus 2022-08-19 15:42:35 UTC 
SUMMARY

SVG files seem to be simply rendered once and then that image is used for rendering the video.
Even with all sorts of transforms, SVG files should be optimally rendered to display them at the viewing resolution.

This would be very useful if you for example import a complex SVG of a map, then zoom around in all sorts of ways, and it will look nice, however this is harder to do now than necessary, and currently the result will be a blurry mess. And people probably have an expectation that the scalability of SVGs will be put to good use with effects.

I don't really expect this to be done when scrolling through the timeline all the time, only during rendering would be fine.

STEPS TO REPRODUCE
1.  Add an SVG file to your project
2.  Put it on the timeline
3.  Apply some effects like transforms with it (for example panning, zooming, rotating with keyframes)
4.  Render the video

OBSERVED RESULT

SVG seems to be rendered once at a certain resolution, and then the raster image is transformed.

EXPECTED RESULT

The SVG will be rendered for displaying it optimally during all frames of the video.

SOFTWARE/OS VERSIONS
Stable version and latest nightly builds
Comment 1 Ralph 2024-02-24 13:16:18 UTC 
I see this and possibly related, the aliasing on fonts on imported SVGs is poor quality to what you see if exporting as PNG from Inkscape.
Comment 2 Ralph 2024-02-24 13:18:11 UTC 
(In reply to Ralph from comment #1)
> I see this and possibly related, the aliasing on fonts on imported SVGs is
> poor quality to what you see if exporting as PNG from Inkscape.

I meant to edit this; the issue is not just fonts.

From what I've seen, I assume Kdenlive renders SVGs at some resolution below 1920x1080 and then upscales, hence the unpleasant aliasing artifacts.

If the code could be changed to pre-render the SVG at a higher (much higher?) resolution, the end result would be great.