Python Opencv 和 Sockets - 以 h264 编码的流式视频

Question

所以我正在尝试制作一个流媒体，将视频从一台计算机流式传输到我的 LAN 上的另一台计算机（或同一台计算机，目前）。我需要它使用尽可能少的带宽，所以我试图在 h264 中编码。我在做这件事时遇到了麻烦，我真的不知道从哪里开始。现在它是用jpg编码的，它是逐帧发送的。但是，我知道这是非常低效的，并且会消耗大量带宽。这是我当前的接收器代码。

import cv2
import socket
import _pickle
import time

host = "192.168.1.196"
port = 25565
boo = True

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # declares s object with two parameters
s.bind((host, port)) # tells my socket object to connect to this host & port "binds it to it"
s.listen(10) # tells the socket how much data it will be receiving.

conn, addr = s.accept()
buf = ''
while boo:
        pictures = conn.recv(128000) # creates a pictures variable that receives the pictures with a max amount of 128000 data it can receive
        decoded = _pickle.loads(pictures) # decodes the pictures
        frame = cv2.imdecode(decoded, cv2.IMREAD_COLOR) # translates decoded into frames that we can see!
        cv2.imshow("recv", frame)
        if cv2.waitKey(1) & 0xFF == ord("q"):  # wait until q key was pressed once and
            break

这是我当前的客户端代码（发件人）：

import cv2
import numpy as np
import socket
import _pickle
from cv2 import *

host = "192.168.1.196"
port = 25565

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  # declares s object with two parameters
s.connect((host, port))  # connects to the host & port
cap = cv2.VideoCapture(1)
cv2.cv.CV_FOURCC('H','2','6','4')
while cap.isOpened(): # while camera is being used
    ret, frame = cap.read()  # reads each frame from webcam
    cv2.imshow("client", frame)
    if ret:
        encoded = _pickle.dumps(cv2.imencode("fourcc", frame)[1]) # encoding each frame, instead of sending live video it is sending pictures one by one
        s.sendall(encoded)
    if cv2.waitKey(1) & 0xFF == ord("q"): # wait until key was pressed once and
        break
cap.release()
cv2.destroyAllWindows()

我只需要一些关于如何对视频进行编码和在 h264 中解码的帮助。

Answer 1

您可以使用 pyzmq 和带有 base64 字符串编码/解码的 publish/subscribe 模式来完成此操作。在服务器端，想法是：

• 从相机流中获取帧
• 使用cv2.imencode从内存缓冲区读取图像
• 使用 base64 将 ndarray 转换为 str 并通过套接字发送

在客户端，我们只是简单地反转这个过程：

• 从套接字读取图像字符串
• 使用 base64 将 str 转换为 bytes
• 使用np.frombuffer + cv2.imdecode 将bytes 转换为ndarray

此方法不应使用太多带宽，因为它仅通过套接字发送字符串。

---

服务器

import base64
import cv2
import zmq

context = zmq.Context()
socket = context.socket(zmq.PUB)
socket.connect('tcp://localhost:7777')

camera = cv2.VideoCapture(0)

while True:
    try:
        ret, frame = camera.read()
        frame = cv2.resize(frame, (640, 480))
        encoded, buf = cv2.imencode('.jpg', frame)
        image = base64.b64encode(buf)
        socket.send(image)
    except KeyboardInterrupt:
        camera.release()
        cv2.destroyAllWindows()
        break

客户

import cv2
import zmq
import base64
import numpy as np

context = zmq.Context()
socket = context.socket(zmq.SUB)
socket.bind('tcp://*:7777')
socket.setsockopt_string(zmq.SUBSCRIBE, np.unicode(''))

while True:
    try:
        image_string = socket.recv_string()
        raw_image = base64.b64decode(image_string)
        image = np.frombuffer(raw_image, dtype=np.uint8)
        frame = cv2.imdecode(image, 1)
        cv2.imshow("frame", frame)
        cv2.waitKey(1)
    except KeyboardInterrupt:
        cv2.destroyAllWindows()
        break