我想使用Python中的套接字编程流式传输网络摄像头提要 [英] I want to stream a webcam feed using socket programming in Python

问题描述

这是我的代码：

#The server receives the data

import socket
from PIL import Image
import pygame,sys
import pygame.camera
from pygame.locals import *
import time

host = "localhost"
port = 1890
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host,port))
s.listen(1)
conn, addr = s.accept()
print "connected by",addr

screen = pygame.display.set_mode((640,480))

while 1:
        data = conn.recv(921637)
        image = pygame.image.fromstring(data,(640,480),"RGB")
        screen.blit(image,(0,0))
        pygame.display.update()
        if not image: 
               break;
        conn.send(data)
conn.close()

客户端。 py

client.py

#The client sends the data

import socket
from PIL import Image
import pygame,sys
import pygame.camera
from pygame.locals import *
import time

host = "localhost"
port = 1890
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))


pygame.init()
pygame.camera.init()
cam = pygame.camera.Camera("/dev/video0",(640,480))
cam.start()

while 1:
        image = cam.get_image()
        data = pygame.image.tostring(image,"RGB")
        s.sendall(data)     

s.close()
print "recieved", repr(data)

只需测试，我尝试了以下代码，但工作正常，但是上面的代码却没有...

Just to test, I tried the following code and it's working fine, but the above does not...

在没有套接字的情况下实现的工作代码：camcapture.py

Working code when implemeted without sockets: camcapture.py

import sys
import time
import pygame
import pygame.camera
from pygame.locals import *

pygame.init()
pygame.camera.init()
cam = pygame.camera.Camera("/dev/video0",(640,480))
cam.start()

screen = pygame.display.set_mode((640,480))

while 1:
        image = cam.get_image()
        data = pygame.image.tostring(image,"RGB")
        img = pygame.image.fromstring(data,(640,480),"RGB")
        screen.blit(img,(0,0))
        pygame.display.update()

错误是：

image = pygame.image.fromstring(data,(640,480),"RGB")
ValueError: String length does not equal format and resolution size

我在哪里出错了？

推荐答案

问题不在于相机。

问题是您在套接字上发送了一个非常大的字符串，并且错误地认为可以使用 conn一次读取整个字符串。 recv（921637）。

The problem is that you send a very large string over the socket and you incorrectly assume that you can read the entire string at once with conn.recv(921637).

您必须多次调用 recv 才能接收全部数据。尝试打印在 client.py 中发送的 data 的长度，并打印 data的长度调用 pygame.image.fromstring 之前的 server.py 中的，您会看到的。

You'll have to call recv multiple times to receive all over your data. Try printing the length of data you send in client.py and print the length of data in server.py before calling pygame.image.fromstring and you'll see.

有几种解决方法：

• 为您发送的每张图片


• 发送数据的大小，以便服务器知道要读取多少数据


• 使用某种结束标记
>

• make a new connection for each image you send
• send the size of your data so the server knows how much data to read
• use some kind of end marker

这是一个简单的示例：

import socket
import pygame
import time

host = "localhost"
port = 1890
pygame.init()
image = pygame.surface.Surface((640, 480))
i=0
j=0
while 1:
    image.fill((i,j,0))
    i+=10
    j+=5
    if i >= 255: i = 0
    if j >= 255: j = 0
    data = pygame.image.tostring(image,"RGB")
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect((host, port))
    s.sendall(data)
    s.close()
    time.sleep(0.5)

接收者：

receiver:

import socket
import pygame

host="localhost"
port=1890

screen = pygame.display.set_mode((640,480))

while 1:
    s=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.bind((host,port))
    s.listen(1)
    conn, addr = s.accept()
    message = []
    while True:
        d = conn.recv(1024*1024)
        if not d: break
        else: message.append(d)
    data = ''.join(message)
    image = pygame.image.fromstring(data,(640,480),"RGB")
    screen.blit(image,(0,0))
    pygame.display.update()

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