How to enable better downscaling?
Posted: 25 Dec 2018 16:43
Hello everyone,
we want to use VLC to use for image and video presentation. In the past we have been using IrfanView for this purpose, but since it has got really poor support for videos, we want to try using VLC from now on. After working through all the configurations to make it fit for our needs, there is just one big issue: The quality of downscaled images (about 4000*3000) is *really* poor, lot's of sharp pixelated edges and moire patterns. It looks almost like nearest neighbor filtering is used.
In the advanced settings there is "Video" -> "Filter" -> "sw-scaling" which allows you to pick a scaling mode. Unfortunately it doesn't really seem to do anything. I.e. we tried changing it and the result is always the same. Our guess is that whole filter isn't enabled. Apparently there used to be an option to do just that (see here) which for some reason was removed in VLC version 3. So we tried adding "swscale" manually into the textbox, but that doesn't appear to do anything and is also gets automatically removed. Like described in the link we tried disabling hardware acceleration (although to my understanding that's not a thing for simple images). If we choose DirectDraw output the filtering is different but still not affected by the "sw-scaling" setting (same with GDI just that that additionally distorts the colors).
At this point my only idea would be to forget about VLC filtering and write a Lua plugin that prescales the images in the playlist, but that sounds like giant, ugly and slow hack.
How do we enable "sw-scaling"? Or is there another way to enable proper filtering?
Thank you.
we want to use VLC to use for image and video presentation. In the past we have been using IrfanView for this purpose, but since it has got really poor support for videos, we want to try using VLC from now on. After working through all the configurations to make it fit for our needs, there is just one big issue: The quality of downscaled images (about 4000*3000) is *really* poor, lot's of sharp pixelated edges and moire patterns. It looks almost like nearest neighbor filtering is used.
In the advanced settings there is "Video" -> "Filter" -> "sw-scaling" which allows you to pick a scaling mode. Unfortunately it doesn't really seem to do anything. I.e. we tried changing it and the result is always the same. Our guess is that whole filter isn't enabled. Apparently there used to be an option to do just that (see here) which for some reason was removed in VLC version 3. So we tried adding "swscale" manually into the textbox, but that doesn't appear to do anything and is also gets automatically removed. Like described in the link we tried disabling hardware acceleration (although to my understanding that's not a thing for simple images). If we choose DirectDraw output the filtering is different but still not affected by the "sw-scaling" setting (same with GDI just that that additionally distorts the colors).
At this point my only idea would be to forget about VLC filtering and write a Lua plugin that prescales the images in the playlist, but that sounds like giant, ugly and slow hack.
How do we enable "sw-scaling"? Or is there another way to enable proper filtering?
Thank you.