Any feedback on this newest patch? On Tue, Aug 30, 2016 at 2:17 PM, Brett Harrison <brett.harri...@zyamusic.com > wrote:
> Since there are differing opinions on how the default fontsize should be > established this patch adds my changes while preserving the current > behavior when fontsize is not specified. > > On Tue, Aug 30, 2016 at 2:43 AM, Nicolas George <geo...@nsup.org> wrote: > >> Le tridi 13 fructidor, an CCXXIV, Brett Harrison a écrit : >> > Before I fix the patch, can you clarify the intended functionality? >> > >> > The docs say that 16 is the default fontsize, however if >> > CONFIG_LIBFONTCONFIG is configured and ffmpeg if called with: >> > >> > -vf drawtext=text=abc:fontcolor=white >> > >> > on my system the font used will be /opt/X11/share/fonts/TTF/Vera.ttf >> (the >> > default chosen by libfontconfig) and the fontsize will be set to 12. >> > >> > However if ffmpeg is called with: >> > >> > -vf >> > drawtext=text=abc:fontcolor=white:fontfile=/opt/X11/share/fo >> nts/TTF/Vera.ttf >> > >> > This is the same font that libfontconfig used, however this time >> fontsize >> > 16 is used as stated in the docs. >> > >> > The difference is this line of code in load_font_fontconfig >> > if (!s->fontsize) >> > s->fontsize = size + 0.5; >> > >> > I didn't set the fontsize in either command, but the output was >> different. >> > Do we want to keep this as is? >> >> I think the current behaviour is correct. >> >> I start with the following principle: when users want something precise >> about aesthetic or other arbitrary settings, they have to say it. >> >> Default values are for the lazy or the careless ones: quick profiling and >> testing when the exact result does not matter much. But as soon as the >> result matters, explicit values must be given. >> >> Do not take me wrong, the default values should be, as much as possible, >> sensible. But for a font size, 12 is as sensible as 16. >> >> Most importantly, backward compatibility should not be an hindrance to >> choosing better default values. We should not change them lightly, but not >> feel forbidden to do so either. >> >> Fontconfig is not just a path search library for finding font files. It >> is a >> complete mechanism for choosing the right font according to several >> conditions set by the user. Including the font size. >> >> There are no less than four levels for choosing the font size: >> >> (1) lavfi's default, 16; >> >> (2) fontconfig's default; >> >> (3) fontconfig's explicit value, as in "Times-12:bold"; >> >> (4) lavfi's explicit value, as in "fontsize=16". >> >> I think the order of precedence should be just that, for the following >> reasons: >> >> - First, of course, (3), (4) > (1), (2), because explicit values are >> always >> more important. >> >> - Second, conflicting explicit values are the users' problem. We can >> produce >> warnings to help diagnose, but in the end it is their choice. (4) > (3) >> is >> slightly easier to implement (distinguishing (3) from (2) requires a bit >> of work), and (4) is more supple, especially when your patch gets >> applied. >> >> - Last, (2) > (1), because fontconfig is more cross-applications than >> lavfi, >> and also because it includes a mechanism for explicit configuration. >> >> Still, the documentation should be clarified, possibly something like >> that: >> "The default value of fontsize is provided by fontconfig if in use or 16 >> when using a font file directly." >> >> Regards, >> >> -- >> Nicolas George >> >> _______________________________________________ >> ffmpeg-devel mailing list >> ffmpeg-devel@ffmpeg.org >> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel >> >> > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel