Telegram animated stickers helper (GIF -> WEBM; ffmpeg-python)

script.py

import os
import glob
from pathlib import Path

import ffmpeg

DEFAULT_FPS = 30
DEFAULT_SMART_DURATION_LIMIT = "2.9"
DEFAULT_SPEED_ADJUST_MODE = "smart"
DEFAULT_FALLBACK_PTS = "1.0"


def process_file(filepath):
    p = Path(filepath)

    job = ffmpeg.input(filepath)
    job = job.filter('fps', fps=DEFAULT_FPS)
    info = ffmpeg.probe(filepath)
    stream = info['streams'][0]
    fmt = info['format']

    if stream['width'] >= stream['height']:
        job = job.filter('scale', 512, -1)
    else:
        job = job.filter('scale', -1, 512)

    if 'duration' in fmt:
        duration = float(fmt['duration'])

        if duration > 3.0:
            job = job.filter('setpts', f"({DEFAULT_SMART_DURATION_LIMIT}/{duration})*PTS")
    else:
        job = job.filter('setpts', f"{DEFAULT_FALLBACK_PTS}*PTS")

    out_path = str(p.with_suffix('.webm'))

    if os.path.exists(out_path):
        out_path = str(p.with_suffix('.telegram.webm'))

    job = (
        job
        .output(
            out_path,
            pix_fmt='yuva420p',
            vcodec='libvpx-vp9',
            an=None,
        )
        .overwrite_output()
    )

    job.run()


if __name__ == "__main__":
    for file in glob.glob("*.gif"):
        process_file(file)