opencv和ffmpeg查询视频信息（python）

1. 用Opencv获取

def get_source_info_opencv(source_name):
    return_value = 0
    try:
        cap = cv2.VideoCapture(source_name)
        width = cap.get(cv2.CAP_PROP_FRAME_WIDTH )
        height = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
        fps = cap.get(cv2.CAP_PROP_FPS)
        num_frames = cap.get(cv2.CAP_PROP_FRAME_COUNT)
        return_value = {"width" : int(width),
                        "height": int(height),
                        "num_frames": int(num_frames),
                        "fps" : int(fps) if not fps == float('inf') else 15}
        # print("{} 
height:{} 
fps:{} 
num_frames:{}".format(width, height, fps, num_frames))
        # show_statisrics(source_name, fps, width, height, num_frames)
    except (OSError, TypeError, ValueError, KeyError, SyntaxError) as e:
        print("init_source:{} error. {}
".format(source_name, str(e)))
        return_value = -1
    return return_value

2. 用ffmpeg获取

注意python运行如下代码有两个条件：

• pip install ffmpeg-opencv
• 在系统安装或者编译ffmpeg(windows、linux、macos)

def get_source_info_ffmpeg(source_name):
    return_value = 0
    assert os.path.exists(source_name)
    try:
        info = ffmpeg.probe(source_name)
        # print(info)
        # print("---------------------------------")
        vs = next(c for c in info['streams'] if c['codec_type'] == 'video')
        format_name = info['format']['format_name']
        codec_name = vs['codec_name']
        duration_ts = float(vs['duration_ts'])
        fps = int(vs['r_frame_rate'][:-2])
        width = vs['width']
        height = vs['height']
        duration = int(float(vs['duration']))
        # 如果只用ffmpeg,這裡不應該使用Opencv
        cap = cv2.VideoCapture(source_name)
        num_frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT)) if cap.get(cv2.CAP_PROP_FRAME_COUNT) else 
            duration * fps

        return_value = {"width": width,
                        "height": height,
                        "num_frames": duration * fps ,
                        "fps": int(fps)}
        show_statisrics(source_name, fps, width, height, num_frames)
        # print("format_name:{} 
codec_name:{} 
duration_ts:{} 
{} 
height:{} 
fps:{}".format(format_name, codec_name, duration_ts, width, height, fps))
    except (OSError, TypeError, ValueError, KeyError, SyntaxError) as e:
        print("init_source:{} error. {}
".format(source_name, str(e)))
        return_value = 0
    return return_value

3. 信息打印

def show_statisrics(source_name, fps, width, height, num_frames):
    print("Video statistics:")
    print("  ----------------------------------------")
    print("  Items      | Info ")
    print("  ----------------------------------------")
    print("  Path       | {:>20s}  ".format(source_name) )
    print("  width      | {:20d} ".format(width) )
    print("  height     | {:20d} ".format(height) )
    print("  num_frames | {:20d} ".format(num_frames) )
    print("  fps        | {:>20d}  ".format(fps) )
    print("  ----------------------------------------")

效果如下：