visualmetrics.py 文件源码

def get_decimate_filter():
    decimate = None
    try:
        filters = subprocess.check_output(
            ['ffmpeg', '-filters'], stderr=subprocess.STDOUT)
        lines = filters.split("\n")
        match = re.compile(
            r'(?P<filter>[\w]*decimate).*V->V.*Remove near-duplicate frames')
        for line in lines:
            m = re.search(match, line)
            if m is not None:
                decimate = m.groupdict().get('filter')
                break
    except BaseException:
        logging.critical('Error checking ffmpeg filters for decimate')
        decimate = None
    return decimate