实时视频传输_切割压缩、丢包统计

UDP实时视频传输

udp连接

原理：

在选择UDP作为传输协议时必须要谨慎。在网络质量令人十分不满意的环境下，UDP协议数据包丢失会比较严重。但是由于UDP的特性：它不属于连接型协议，因而具有资源消耗小，处理速度快的优点，所以通常音频、视频和普通数据在传送时使用UDP较多，因为它们即使偶尔丢失一两个数据包，也不会对接收结果产生太大影响。比如我们聊天用的ICQ和QQ就是使用的UDP协议。

在现场测控领域，面向的是分布化的控制器、监测器等，其应用场合环境比较恶劣，这样就对待传输数据提出了不同的要求，如实时、抗干扰性、安全性等。基于此，现场通信中，若某一应用要将一组数据传送给网络中的另一个节点，可由UDP进程将数据加上报头后传送给IP进程，UDP协议省去了建立连接和拆除连接的过程，取消了重发检验机制，能够达到较高的通信速率。

1.发送端

import threading
import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
t = threading.Thread(target=mythread, args=(sock, string, ('192.168.201.106', 9999)))

2.接收端

import socket
import time
import threading
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(('192.168.201.106', 9999))
data, addr = s.recvfrom(60000)

图像处理

旋转变换

img = img.transpose(Image.ROTATE_180)
img = img.transpose(Image.FLIP_LEFT_RIGHT)

这分别为图像旋转和左右翻转变换，我们拍到的视频是镜像翻转对称的，因此要进行以下处理，才能看到正像。

图像转Bytes

这个我找到了好几种方法：cv2转Image转bytes、cv2转np转bytes、

cv2转np转Image转bytes

image = Image.fromarray(cv.cvtColor(frame, cv.COLOR_BGR2RGB))
string = Image.fromarray(np.uint8(image)).tobytes()

cv2转np转bytes

image = Image.fromarray(cv.cvtColor(frame, cv.COLOR_BGR2RGB))
string=np.uint8(image).tostring()

pygame转bytes

Img = pygame.image.load('/home/pi/实验/视频传输数据采集/test.jpg')
string = pygame.image.tostring(Img, "RGB")

Bytes转图片

Image

img = Image.frombuffer("RGB", (160, 120), data)#, 'raw', "L", 0, 1

pygame

img = pygame.image.frombuffer(data, (160, 120), "RGB")

源码

发送端

# coding:utf-8
import cv2 as cv
import time
import threading
import socket
import numpy as np
from PIL import Image
def mythread(sock, data, addr):
    sock.sendto(data, addr)
    print("已发送 " + str(len(data)) + " bytes")
    sock.close()
def main():
    print("begin")
    start = time.clock()
    capture = cv.VideoCapture(0)
    while True:
        ret, frame = capture.read()
        frame = cv.flip(frame, -1)
        frame = cv.resize(frame, (160, 120))
        image = Image.fromarray(cv.cvtColor(frame, cv.COLOR_BGR2RGB))
        string = Image.fromarray(np.uint8(image)).tobytes()
        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        t = threading.Thread(target=mythread, args=(sock, string, ('192.168.201.106', 9999)))
        t.start()
        if cv.waitKey(10) & 0xff == ord('q'):
            capture.release()
            break
main()
cv.destroyAllWindows()

接收端

#coding=utf-8
import socket
import time
import threading
import numpy as np
import cv2
from PIL import Image
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(('192.168.201.106', 9999))
print('Waiting for connection...')
start = time.perf_counter()
while not False:
    data, addr = s.recvfrom(60000)
    if time.perf_counter() - start > 1:
        start = time.perf_counter()
    print('Received from %s:%s.' % addr)
    img = Image.frombuffer("RGB", (160, 120), data)#, 'raw', "L", 0, 1
    img = img.transpose(Image.ROTATE_180)
    img = img.transpose(Image.FLIP_LEFT_RIGHT)
    crop_im = cv2.cvtColor(np.array(img), cv2.COLOR_RGBA2BGRA)
    cv2.imshow('UDP 视频传输',crop_im)
    if cv2.waitKey(1) == 27:  # 按下“ESC”退出
        break
    print('have received one frame')

udp视频传输结果：

图片的切割与拼接

各种类型转bytes传输

对图片进行jpg压缩与还原

jpg压缩后的切割与传输

传输时延、丢包率

auto lo
iface lo inet loopback

iface eth0 inet manual


auto wlan0
iface wlan0 inet static 
address 192.168.201.165
netmask 255.255.255.0
gateway 192.168.201.1
pre-up wpa_supplicant -Dwext -i wlan0 -c/etc/wpa_supplicant/wpa_supplicant2.conf -B

allow-hotplug wlan0
iface wlan0 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant2.conf

auto wlan1
iface wlan1 inet static 
address 192.168.201.165
netmask 255.255.255.0
gateway 192.168.201.1
pre-up wpa_supplicant -Dwext -i wlan1 -c/etc/wpa_supplicant/wpa_supplicant.conf -B

allow-hotplug wlan1
iface wlan1 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

sudo create_ap -n wlan0 car_wifi xmu20111 -c 1

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=CN

network={
ssid=”xmu201_1”
psk=”xmu20111”
key_mgmt=WPA-PSK
}

sudo nano /media/pi/rootfs/etc/network/interfaces
sudo nano /etc/network/interfaces
cd /media/pi/rootfs/etc/wpa_supplicant/

sudo nano /media/pi/rootfs/etc/dhcpcd.conf
sudo nano /etc/dhcpcd.conf

dhcp 域名解析

sudo nano /etc/dhcpcd.conf
# A sample configuration for dhcpcd.
# See dhcpcd.conf(5) for details.

# Allow users of this group to interact with dhcpcd via the control socket.
#controlgroup wheel

# Inform the DHCP server of our hostname for DDNS.
hostname

# Use the hardware address of the interface for the Client ID.
clientid
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as per RFC4361.
#duid

# Persist interface configuration when dhcpcd exits.
persistent

# Rapid commit support.
# Safe to enable by default because it requires the equivalent option set
# on the server to actually work.
option rapid_commit

# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
# Most distributions have NTP support.
option ntp_servers
# Respect the network MTU.
# Some interface drivers reset when changing the MTU so disabled by default.
#option interface_mtu

# A ServerID is required by RFC2131.
require dhcp_server_identifier

# Generate Stable Private IPv6 Addresses instead of hardware based ones
slaac private

# A hook script is provided to lookup the hostname if not set by the DHCP
# server, but it should not be run by default.
nohook lookup-hostname

interface eth0
static ip_address=192.168.3.233/24
static routers=192.168.3.1
static domain_name_servers=114.114.114.114

interface wlan0
#static ip_address=172.16.233.233/16
#static routers=172.16.0.1
static domain_name_servers=114.114.114.114

static ip_address=10.42.0.233/24
static routers=10.42.0.1