ffmpeg 調節視頻聲音大小

def get_video_audio():
    command = 'ffmpeg -nostats -i D:/OTT/test.mp4 -filter_complex ebur128 -f null -'
    result = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    info = result.stdout.read()
    print(info.decode('utf-8'))

 降低視頻樣本聲音
def down_video_audio(videodir,outdir,downvalue=10):
    file_list = os.listdir(videodir)
    os.makedirs(outdir, exist_ok=True)
    count = len(file_list)
    for line_index, file in enumerate(file_list):
        print('當前進度: {}/{}'.format(line_index + 1, count))
        fileName = os.path.join(videodir, file)
        outfile = os.path.join(outdir, file)
        down_audio(fileName, outfile, downvalue)

    print(file_list)


# 調節視頻聲音大小
def down_audio(sourcfile, outfile,downvalue):
    '''
    使用ffmpeg進行視頻的聲音大小調節
    :param sourcfile: 源文件
    :param outfile:輸出文件
    :param downvalue:增加或減少的分貝值，10 增加10分貝，-10：減少10分貝
    :return:
    '''
    # 把視頻的聲音降低10分貝
    # 應用命令: ffmpeg -i D:\OTT\test.mp4 -af volume=-10dB -y D:\OTT\out.mp4
    cmd = 'ffmpeg -i {} -af volume={}dB -y {}'.format(sourcfile, downvalue, outfile)
    flag = os.system(cmd)

    if flag == 0:
        return True
    return False

if __name__ == '__main__':
    # control_process()
    videodir='D:/OTT/5秒鐘樣本/20210301'
    outdir='D:/OTT/5秒鐘樣本修改聲音/20210301'
    down_video_audio(videodir, outdir)