dump_frames.py 文件源码

def dump_frames(video_path, output_directory, frames_per_second):
    """Dump frames at frames_per_second from a video to output_directory.

    If frames_per_second is None, the clip's fps attribute is used instead."""
    clip = VideoFileClip(video_path)
    info_path = '{}/info.json'.format(output_directory)
    name_format = '{}/frame%04d.png'.format(output_directory)

    if frames_per_second is None:
        frames_per_second = clip.fps
    frames_already_dumped_helper = lambda: \
            frames_already_dumped(video_path, output_directory,
                                  frames_per_second, info_path,
                                  name_format, clip.duration)
    if frames_already_dumped_helper():
        logging.info('Frames for {} exist, skipping...'.format(video_path))
        return

    successfully_wrote_images = False
    try:
        clip.write_images_sequence(
            name_format.format(output_directory),
            fps=frames_per_second)
        successfully_wrote_images = True
    except Exception as e:
        logging.error("Failed to dump images for %s", video_path)
        logging.error(e)

    if successfully_wrote_images:
        info = {'frames_per_second': frames_per_second,
                'input_video_path': os.path.abspath(video_path)}
        with open(info_path, 'wb') as info_file:
            json.dump(info, info_file)

        if not frames_already_dumped_helper():
            logging.error(
                "Images for {} don't seem to be dumped properly!".format(
                    video_path))