[FFmpeg-devel] drawtext option

[su.gao]

I found that the box_length is  shorter  than the text_length, and there is no option to adapt（Equal）.

So  I suggest ffmpeg.org can add a opption(like boxw_equal_textw) to adapt it !

the old source:
    box_w = FFMIN(width - 1 , max_text_line_w);
    box_h = FFMIN(height - 1, y + s->max_glyph_h);

the new source:
    if(0==s->boxw_equal_textw){
          box_w = FFMIN(width - 1 , max_text_line_w);
    }else{
          box_w =   (int)s->var_values[VAR_TEXT_W];   
    }