python使用ffmpeg推流出现OSError: [Errno 2] No such file or directory

具体错误如下：

Traceback (most recent call last):
  File "test.py", line 23, in <module>
    pipe = subprocess.Popen(command, shell=False, stdin=subprocess.PIPE
  File "/usr/lib/python2.7/subprocess.py", line 711, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1343, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

错误出现场景：使用python开子进程，执行ffmpeg推流命令时候出现的

import cv2
import subprocess


rtmp = r'rtmp://***'

cap = cv2.VideoCapture(0)
size = (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)), int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))
sizeStr = str(size[0]) + 'x' + str(size[1])
command = ['ffmpeg',
    '-y', '-an',
    '-f', 'rawvideo',
    '-vcodec','rawvideo',
    '-pix_fmt', 'bgr24',
    '-s', sizeStr,
    '-r', '25',
    '-i', '-',
    '-c:v', 'libx264',
    '-pix_fmt', 'yuv420p',
    '-preset', 'ultrafast',
    '-f', 'flv',
    rtmp]
pipe = subprocess.Popen(command, stdin=subprocess.PIPE)
while cap.isOpened():
    success, frame = cap.read()
    if success:
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
        pipe.stdin.write(frame.tostring())
cap.release()
pipe.terminate()

解决办法：
查阅了网上没有一个有用的，要不就是乱写，要不就是求助，我在stackoverflow查到了如下解决办法，我使用成功解决问题，可以当作各位小伙伴的借鉴。

sudo ln -s /usr/bin/python /usr/local/bin/python