On Thu, Dec 13, 2012 at 9:28 AM, Brian Matherly <[email protected]> wrote: >>When I create a video with some background color and text overlayed on it, >>some kind of jagged edges appear around the text when I view video in full >>screen. > >>Here is the script that I have used to overlay text on background color, >> >><producer in="0" out="120"> >> <property name="mlt_service">colour</property> >> <filter> >> <property name="mlt_service">dynamictext</property> >> <property name="argument"><![CDATA[THE WAY IS NOT IN THE SKY, >> way is not in the sky, >>The way is in the heart >>]]></property> >> <property name="family">Art brush</property> >> <property name="size">40</property> >> <property name="fgcolour">0xFF0000FF</property> >> <property name="weight">640</property> >> <property name="bgcolour">0x00000000</property> >> <property name="olcolour">0xFF00005</property> >> <property name="outline">1</property> >> <property name="geometry">10%/50%:100%/100%</property> >> </filter> >> <property name="colour">0x0099FFff</property> >> </producer> >> >> >>If I use properties like weight, olcolour, and outline, I get better text >>upto some extent but still some jagged edges appear around text. >>If I set video bitrate 1000k, in the final video I get video bitrate upto >>165k. > > > I see what you mean. I expected that increasing the font size would improve > the edges. But it has no effect for me. > > Dan, is it possible that the compositor is adding an aliasing effect? I > expect that the pango image will not be the same dimensions as the frame - > and therefore the compositor will scale it. Is that correct? >
Yes, there are significant quality issues. The composite bounding geometry being used here is set for 100% = the size of the profile. So, I doubt that it is scaling. However, if you use a non-square pixel profile, then the title's is going to be scaled horizontally to conform its square pixels to the profile's sample aspect ratio. If you combine that with the sdl consumer's default scaler setting of nearest neighbor, you will get poor quality. However, in my brief tests I specifically avoided these pitfalls. I even found the problem when using the Qt-based kdenlive titler. Certainly, the combination of the colors chosen and SD resolution limit the quality, but I noticed that the affine transition's compositor does give better results. The regular composite transition uses yuv422 with its reduced chroma resolution, and that at least partially contributes to the problem. Perhaps when you combine that with composite's lack of interpolation and these colors and low resolution. -- +-DRD-+ ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Mlt-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mlt-devel
