På Tue, 17 Jan 2012 20:32:38 +0100, skrev Michal Fapso <michal.fa...@gmail.com>:
I am not able to set Hue to -0.0, but when I just moved a bit the hue slider, the blue artifacts disappeared! And now there are no artifacts evein with Hue=0.0! So basically, I cannot make it to show those artifacts now :o) However, there is still another kind of block artifacts in the sky: http://www.fit.vutbr.cz/~ifapso/download/cinelerra_vs_avidemux_block_artifacts.png
That could be due to lacking chroma interpolation. As far as I know, Cinelerra upscales 4:2:0 video to 4:4:4 simply by "nearest neighbour"; repeating each colour pixel 2x2 times. Such blocky 2x2 colour pixels will give the colour macroblocks really sharp edges, which will stand out like mach bands when you raise the colour contrast (i.e. the saturation). Avidemux apparently filters the chroma properly, avoiding this. You may try a workaround: Apply a blur effect _before_ the hue/saturation effect, and make sure your colour format is YUV(A), not RGB(A). Enable only blur of "G" and "B" (which means U and V, since you are in YUV mode), and set the blur radius to 3. It helps quite a lot, and since the luma is left alone, the result is still sharp. I still see a lot of flickering blocks in the top of the image, though. Maybe Avidemux has a dynamic deblocker enabled, too? Anyhow, your MJPEG video is _very_ blocky! Try upping the bitrate a few notches. PS! Hm, I'd suggest setting the blur radius to 8, or 16 even! The colour signal isn't exactly crisp in the first place. -- Herman Robak _______________________________________________ Cinelerra mailing list Cinelerra@skolelinux.no https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
