renders the string for video frames

render_video_frame_str.py

# used in conjunction with https://gist.github.com/xziyue/0e83c7c6938d125b05d5bcad5e12e43a

import pickle
from PIL import Image, ImageFont, ImageDraw, ImageOps
import os
from multiprocessing import Pool


def generate_render_param(text_dim, font, fontsize, spacing):
    test_str = '\n'.join([' ' * text_dim[1] for _ in range(text_dim[0])])
    test_font = ImageFont.truetype(font, fontsize)
    dummy_img = Image.new('L', (1, 1))
    dummy_draw = ImageDraw.Draw(dummy_img)
    dummy_image_size = dummy_draw.multiline_textsize(test_str, test_font, spacing=spacing)
    ret = {
        'image_font': test_font,
        'image_size': dummy_image_size,
        'spacing': spacing
    }

    return ret


def render_text(param, text):
    img = Image.new('L', param['image_size'], 255)
    draw = ImageDraw.Draw(img)
    draw.multiline_text((0, 0), text, font=param['image_font'], spacing=param['spacing'])
    return img


def generate_frame_task(render_param_args, i, str):
    render_param = generate_render_param(**render_param_args)
    img = render_text(render_param, str)
    inv_img = ImageOps.invert(img)
    inv_img.save(os.path.join(os.getcwd(), 'frames', 'frame{:03d}.png'.format(i)))


if __name__ == '__main__':
    with open('frames.pickle', 'rb') as infile:
        final_result = pickle.load(infile)

    if not os.path.exists('frames'):
        os.mkdir('frames')

    pool = Pool(10)
    params = [(final_result['render_param_args'], i, final_result['frames'][i]) for i in
              range(len(final_result['frames']))]
    pool.starmap(generate_frame_task, params, chunksize=20)