1.概述

在一个测试项目中，有一个需求是要在测试过程中，播放一段living video streaming. 上网查了一下，可以利用ffmpeg,opencv等技术来实现。但是实验后发现效果不太理想，而测试用例里建议是使用vlc来播放这个视频流，故采用python-vlc模块，来实现。经测试，效果满足测试需求。

2.opencv demo

虽然没有采用opencv的方案，但是发现这个 demo在对http视频流方面还是可以使用的。

import numpy as np
import cv2

#cap = cv2.VideoCapture(0)
cap = cv2.VideoCapture(r'http://admin:admin@192.168.2.161:8081')
# 定义解码器并创建VideoWrite对象
# linux: XVID、X264; windows:DIVX
# 20.0指定一分钟的帧数
fourcc = cv2.VideoWriter_fourcc(*'DIVX')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640, 480))

while (cap.isOpened()):
    ret, frame = cap.read()
    if ret == True:
        frame = cv2.flip(frame, 0)

        # 写入帧
        out.write(frame)

        cv2.imshow('frame', frame)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    else:
        break

# 释放内存
cap.release()
out.release()
cv2.destroyAllWindows()

3.python-vlc demo

这个demo就是项目中所用到的用于播放rtsp视频流的模块，主要难点可能会出现在环境搭建上。

import os
import vlc
import time
def get_player(url='rtsp://192.168.2.134:8554/live'):
    Instance = vlc.Instance()
    player = Instance.media_player_new()
    Media = Instance.media_new(url)
    Media.get_mrl()
    player.set_media(Media)
    player.play()
    return player

def get_player_state(player):
      is_playing = player.is_playing()#playing:1 ;other:0
      will_play = player.will_play()
      get_state = player.get_state()
      print 'is_playing: ',is_playing
      print 'will_play: ', will_play
      print 'get_state: ', get_state

def get_player_para(player):
    length = player.get_length()
    width = player.video_get_width()
    size = player.video_get_size()
    title = player.video_get_title_description()
    video_track = player.video_get_track_description()
    audio_track = player.audio_get_track_description()
    fps = player.get_fps()
    rate = player.get_rate()
    track_count = player.video_get_track_count()
    track = player.video_get_track()
    print 'length: ',length
    print 'width: ',width
    print 'size: ', size
    print 'title: ',title
    print 'video_track: ',video_track
    print 'audio_track: ',audio_track
    print 'fps: ',fps
    print 'rate: ', rate
    print 'track_count: ',track_count
    print 'track: ',track

def vlc_main():
    timestamp = time.time()
    while time.time()-timestamp < 400:
        player = get_player()
        time.sleep(1)  # must delay at least one second
        if player.is_playing():
            time.sleep(10)
            get_player_para(player)
            player.video_take_snapshot(num=0, psz_filepath=os.getcwd(), i_width=1080, i_height=360)
            #time.sleep(10)
            player.release()
            return
        player.release()
    player.release()
    print '###########################'
    print 'Fail: cannot find any video'
    print '###########################'

if __name__ == '__main__':
    vlc_main()