Quick transform mp4 to webm for telegram sticker

mp42webm.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright (C) 2022 KunoiSayami
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from __future__ import annotations
import subprocess
import argparse

from dataclasses import dataclass


@dataclass
class Resolution:
    length: int
    weight: int

    @classmethod
    def new(cls, ffprobe_output: str) -> Resolution:
        return cls(*list(map(int, ffprobe_output.split('x'))))

    def scale(self, px: int = 512) -> Resolution:
        ratio = px / max(self.length, self.weight)
        return Resolution(self.transform(self.length * ratio), self.transform(self.weight * ratio))

    @staticmethod
    def transform(output: float) -> int:
        output = int(output)
        if output % 2:
            output += 1
        return output

    def __str__(self) -> str:
        return f'{self.length}x{self.weight}'


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('file', nargs='+')
    parser.add_argument('--target', default=512, type=int)
    matches = parser.parse_args()
    for file in matches.file:
        # source: https://superuser.com/a/841379
        p = subprocess.Popen(['ffprobe', '-v', 'error', '-select_streams', 'v:0', '-show_entries',
                              'stream=width,height', '-of', 'csv=s=x:p=0', file],
                             stdout=subprocess.PIPE)
        output = p.communicate()[0].decode().strip()
        # source: https://superuser.com/a/624564
        subprocess.Popen(['ffmpeg', '-y', '-i', file, '-s', str(Resolution.new(output).scale(matches.target)),
                          '-c:a', 'copy', '.tmp.mp4']).wait()

        if p.returncode != 0:
            print('Got scale error in file', file)
            break
        # source: https://stackoverflow.com/a/47512301
        p = subprocess.Popen(['ffmpeg', '-y', '-i', '.tmp.mp4', '-c:v', 'libvpx-vp9',
                              '-crf', '30', '-b:v', '0', '-b:a', '128k', '-c:a',
                              'libopus', f'{file}.webm'])
        p.wait()
        if p.returncode != 0:
            print('Got transform error in file', file)
            break


if __name__ == '__main__':
    main()