Convert animated WEBP to MP4

 Animated WebP, similar to animated GIF, is not the best video format to work with, but this is what the usual SVD (image or text to video) and ComfyUI will generate.

Unfortunately, FFMPEG does not support WebP to MP4 conversion yet, so this simple frame-by-frame conversation had to be done. As it's generating a PNG for each frame, it's rather slow, so it's only suitable for short animations.

The below simple python code converts the animated WebP into MP4, using the predefined FPS.

Don't forget to 

pip3 install pillow moviepy

import os
import shutil
import tempfile
import argparse
from moviepy.video.io.ImageSequenceClip import ImageSequenceClip
import PIL.Image

def analyse_image(path):
    im = PIL.Image.open(path)
    results = {
        'size': im.size,
        'mode': 'full',
    }
    try:
        while True:
            if im.tile:
                tile = im.tile[0]
                update_region = tile[1]
                update_region_dimensions = update_region[2:]
                if update_region_dimensions != im.size:
                    results['mode'] = 'partial'
                    break
            im.seek(im.tell() + 1)
    except EOFError:
        pass
    return results

def process_image(path, temp_dir):
    images = []
    mode = analyse_image(path)['mode']

    im = PIL.Image.open(path)

    i = 0
    p = im.getpalette()
    last_frame = im.convert('RGBA')

    try:
        while True:
            basename = os.path.basename(path)
            output_folder = temp_dir
            frame_file_name = os.path.join(output_folder, f'{os.path.splitext(basename)[0]}-{i}.png')
        
            print(f"saving {path} ({mode}) frame {i}, {im.size} {im.tile} to {frame_file_name}")

            if '.gif' in path:
                if not im.getpalette():
                    im.putpalette(p)

            new_frame = PIL.Image.new('RGBA', im.size)

            if mode == 'partial':
                new_frame.paste(last_frame)

            new_frame.paste(im, (0, 0), im.convert('RGBA'))
           
            new_frame.save(frame_file_name, 'PNG')
            images.append(frame_file_name)
            i += 1
            last_frame = new_frame
            im.seek(im.tell() + 1)
    except EOFError:
        pass
    return images

def webp_mp4(input_file, output_file=None, fps=20):
    temp_dir = tempfile.mkdtemp()
    try:
        images = process_image(input_file, temp_dir)
        if output_file is None:
            output_file = os.path.splitext(input_file)[0] + '.mp4'
        clip = ImageSequenceClip(images, fps=fps)
        clip.write_videofile(output_file)
        return [output_file]
    finally:
        shutil.rmtree(temp_dir)

def parse_arguments():
    parser = argparse.ArgumentParser(description="Convert WEBP to MP4")
    parser.add_argument("input_file", help="Input file name (.webp)")
    parser.add_argument("-o", "--output_file", help="Output file name (optional)")
    parser.add_argument("--fps", type=int, default=20, help="Frames per second (default: 20)")

    return parser.parse_args()

if __name__ == "__main__":
    args = parse_arguments()
    webp_mp4(args.input_file, args.output_file, args.fps)