mpv fc-match: A quick and dirty way to determine whether you have all the fonts required in an ass file

mfm.py

#!/usr/bin/env python

import os
import argparse
import subprocess


def get_fonts_from_ass_file(ass_file):
    try:
        with open(ass_file) as f:
            ass = f.readlines()
    except UnicodeDecodeError:
        with open(ass_file, encoding='utf-16') as f:
            ass = f.readlines()

    # Format: Name, Fontname, Fontsize, ...
    fonts = set()
    for line in ass:
        line = line.strip()
        if not line.startswith('Style:'):
            continue

        fontname = line.split(',')[1]
        fontname = fontname.strip('@')
        fonts.add(fontname)

    return fonts


def fc_match(fontname, fonts_conf=None):
    # FONTCONFIG_FILE could only be absolute path
    if not fonts_conf.startswith('/'):
        fonts_conf = os.path.abspath(os.path.expanduser(fonts_conf))
    # fc-match escapes all '-' chars internally,
    # we also need to escape them, or no results would return
    fontname = fontname.replace('-', r'\-')
    cmd = ['fc-match', fontname, 'file', 'fullname']
    env = os.environ.copy()
    env['FONTCONFIG_FILE'] = fonts_conf
    try:
        _output = subprocess.check_output(cmd, env=env)
    except subprocess.CalledProcessError:
        _output = ':ERROR:ERROR'
    # :fullname=Noto Sans:file=/usr/share/fonts/noto/NotoSans-Regular.ttc
    output = _output.decode('utf-8').strip().split(':')
    pretty_output = '{} => \t{}, {}'.format(fontname, output[2], output[1]).replace('\\', '')
    print(pretty_output)


def main():
    argparser = argparse.ArgumentParser()
    argparser.add_argument('-c', '--fonts-conf', default='~/.config/mpv/fonts.conf')
    argparser.add_argument('ass', nargs='+')
    args = argparser.parse_args()

    fonts = set()
    for a in args.ass:
        _fonts = get_fonts_from_ass_file(a)
        fonts = fonts | _fonts
    for font in fonts:
        fc_match(font, args.fonts_conf)


if __name__ == '__main__':
    main()