src/youtube/thumbnail.py

   1 import yaml
   2 from PIL import Image, ImageDraw, ImageFont
   3
   4
   5 def split_to_lines(text, draw, font, max_width):
   6     words = text.split()
   7     current = ''
   8     while words:
   9         new_words = []
  10         new_words.append(words.pop(0))
  11         while len(new_words[-1]) == 1 and words:
  12             new_words.append(words.pop(0))
  13         new_words = ' '.join(new_words)
  14         new_line = ' '.join([current, new_words]).strip()
  15         width = draw.textsize(new_line, font=font)[0]
  16         if width > max_width:
  17             yield current
  18             current = new_words
  19         else:
  20             current = new_line
  21     if current:
  22         yield current
  23
  24
  25 def draw_box(img, d, context, get_font_path, scale):
  26     newimg = Image.new(
  27         'RGBA',
  28         (
  29             img.size[0] - d.get('x', 0),
  30             d.get('max-height', img.size[1] - d.get('y', 0)),
  31         )
  32     )
  33
  34     draw = ImageDraw.Draw(newimg)
  35     cursor = 0
  36     for item in d['items']:
  37         if item.get('vskip'):
  38             cursor += int(round(item['vskip'] * scale))
  39         text = item['text'].format(**context)
  40         if not text:
  41             continue
  42         if item.get('uppercase'):
  43             text = text.upper()
  44         font = ImageFont.truetype(
  45             get_font_path(item['font-family']),
  46             int(round(item['font-size'] * scale)),
  47             layout_engine=ImageFont.LAYOUT_BASIC
  48         )
  49         max_width = item.get('max-width', newimg.size[0])
  50
  51         for line in split_to_lines(text, draw, font, max_width):
  52             realheight = draw.textsize(line, font=font)[1]
  53             if cursor + realheight > newimg.size[1]:
  54                 return False
  55             draw.text((0, cursor), line, font=font, fill=item.get('color'))
  56             cursor += int(round(item['line-height'] * scale))
  57
  58     img.paste(newimg, (d.get('x', 0), d.get('y', 0)), newimg)
  59     return True
  60
  61
  62 def draw_box_with_scaling(img, d, context, get_font_path):
  63     scale = 1.0
  64     while scale > 0:
  65         if draw_box(img, d, context, get_font_path, scale):
  66             return True
  67         scale -= 0.05
  68
  69
  70
  71 def create_thumbnail(background_path, defn, context, get_font_path):
  72     img = Image.open(background_path)
  73     d = yaml.load(defn)
  74     for boxdef in d['boxes']:
  75         if not draw_box_with_scaling(img, boxdef, context, get_font_path):
  76             raise ValueError()
  77     return img