[FFmpeg-user] drawtext so that it cover whole page

[anshul]

On 01/27/2014 04:04 PM, anshul wrote:
> On 01/27/2014 03:52 PM, Carl Eugen Hoyos wrote:
>> anshul <anshul.ffmpeg <at> gmail.com> writes:
>>
>>> I want to use  drawtext filter of ffmpeg so that my
>>> fontsize is automatically increased in such a way,
>>> so that it cover whole frame.
>> What happens if you set the video height as fontsize?
>>
>> Carl Eugen
>>
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>> ffmpeg-user at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> If i set fontsize as some percentage of video  height, then it would 
> work only for single word not for paragraphs
>
> I am looking for solution for paragraphs, just now my code is too 
> dirty it works some time but
> also fails many time, since I have not consider actual rndered height 
> but it I am considering max_glyph_w max_glyph_h
> for a particular font on basis of font size
>
> If anyone interested, this is some part of my code in python
>
>     //arialbd character have 4/3 w/h ratio
>     font_size = int(math.sqrt( (w*h*4)/ (len(istr) *3) ))
>
>         if mlen > (w/font_size):
>             font_size = w/mlen
>
>         line_split = 2*(w/font_size)
>         font_size = str(font_size)
>         out_word = ""
>         sword = ""
>         num_lines = 1
>         for word in istr.split(" "):
>             if len(sword + word) > line_split:
>                 out_word = out_word + sword + "\f"
>                 sword = word
>                 num_lines += 1
>             else:
>                 sword = sword + " " + word
>         out_word = out_word + sword
>
>
>
>
> Thanks
> Anshul
Hi

I have generated the code to wrap all the text according aspect ratio in C++
     std::string test_str = "String geometry\n\nThis is a long string 
meant to display in a"
             "in One Frame. Some lines are very long, and then again 
there are paragraph"
             "breaks.\n\nThe text widget shall wrap words, but be 
neither too big nor too"
             "small, and have a pleasing aspect ratio (say, in pixels, 
4:3 or 8:3).";

     int nl_count = 0;
     double test_len = (double)test_str.length();

     double w0 = 0;
     double h0 = 0;


     for(unsigned int i =0;i<test_str.length();i++)
     {
         if(test_str.at(i) == '\n')
             nl_count++;
     }

     w0 = round(8.0/3.0 * sqrt(test_len));
     h0 = round(3.0/8.0 * sqrt(test_len)) + nl_count;

     std::cout <<w0<<"\t"<<h0<<std::endl;

if any one think that it would be good idea to add one more flag of 
autofit text on image in draw text filter
I could change this code to fit the need of convention of ffmpeg.

any way if some one else want to use the drawtext in autofit way he can 
use this code, and ratio of h0 and videoheight

Thanks
Anshul