本篇介紹ESP8266在OLED上播放視頻：

電腦端Python程序作為視頻數(shù)據(jù)的服務器，借助OpenCV實時讀取視頻幀，并進行二值圖像轉換，尺寸調整，再將二值圖像轉為數(shù)組，并以二進制形式的數(shù)據(jù)通過socket方式無線發(fā)送給ESP8266。

ESP8266采用Arduino IDE編程，借助U8g2庫，將圖像數(shù)據(jù)實時顯示到OLED屏幕中。

1 ESP8266端視頻幀接收與播放程序

ESP8266作為socket客戶端，接收服務端發(fā)送的圖像幀數(shù)據(jù)，進行顯示。

ESP8266使用Arduino IDE環(huán)境進行開發(fā)。

1.1 WIFI初始化與服務器連接

#define IP "192.168.5.100"
#define PORT 8080

void initWiFi()
{
  Serial.print("Connecting WiFi...");
  WiFi.mode(WIFI_STA); //配置WIFI為Station模式
  WiFi.begin(ssid, pass); //傳入WIFI熱點的ssid和密碼
  while (WiFi.status() != WL_CONNECTED) //等待連接成功
  {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP()); //打印自己的IP地址

  client.connect(IP, PORT);
}

1.2 視頻顯示主循環(huán)

uint8_t testb[1024] = {};

void loop()
{
  //Serial.println("hello esp8266");
  delay(10);
  while (client.available())
  {
    delay(12);
    client.read(testb, 1024);
    u8g2.firstPage();
    do {
      u8g2.drawXBM(0, 0, 128, 64, testb);
    } while (u8g2.nextPage());
  }
}

2電腦端視頻編碼發(fā)送程序

電腦端作為socket服務器端，將視頻幀數(shù)據(jù)發(fā)送出去。

電腦端采用Python3編程，借助OpenCV實現(xiàn)視頻的讀取與圖像數(shù)據(jù)格式轉換。

2.1 主程序

程序的基本思想是：

利用OpenCV讀取視頻文件

對視頻幀的圖像，進行尺寸修改

對圖像進行二值化處理

將二值圖像轉換為數(shù)組

將數(shù)組通過socket發(fā)送出去

video_path="badapple_320240_xvid.mp4"
    
def PlayVideo(video_path, client):
    endian          = 'L'
    color_reverse   = 'false'
    
    c = 0#累計幀數(shù)
    timeF = 8#隔x幀截一次圖
    
    video = cv2.VideoCapture(video_path) #打開視頻
    player = MediaPlayer(video_path) #打開音頻
    while True:
        grabbed, frame= video.read()
        audio_frame, val = player.get_frame()
        if not grabbed:
            print("End of video")
            break
        if cv2.waitKey(28) & 0xFF == ord("q"):
            break
        cv2.imshow("Video", frame)
        if val != 'eof' and audio_frame is not None:
            img, t = audio_frame

        if (c % timeF == 0):  # 每隔timeF幀進行存儲操作
            frame = cv2.resize(frame,(128,64))#調整尺寸
            frame = binary_image(frame)#二值化
            matrix = img_to_matrix(frame, endian, color_reverse)
            data = bytes(matrix)
            client.send(data)

        c = c + 1
        #time.sleep(0.2)
        #cv2.waitKey(1)
            
    video.release()
    cv2.destroyAllWindows()

###############
client = 0
client = socket_start()
PlayVideo(video_path, client)

2.2 圖像轉為數(shù)組

利用OpenCV，將圖像轉為黑白圖像：

def binary_image(image):#將圖像處理為二值化的程序
    gray = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)  #把輸入圖像灰度化
    h, w =gray.shape[:2]
    m = np.reshape(gray, [1,w*h])
    mean = m.sum()/(w*h)
    ret, binary =  cv2.threshold(gray, mean, 255, cv2.THRESH_OTSU)
    return binary

然后再轉為數(shù)組：

def img_to_matrix(frame, endian, color_reverse):
    width = frame.shape[1] #128
    height = frame.shape[0] #64

    if endian == 'B':
        byte_reverse = True
    else:
        byte_reverse = False

    if color_reverse == 'true':
        color_reverse = True
    else:
        color_reverse = False

    unalign = 0
    matrix = list()
    
    if (width%8) != 0:
        unalign = 1
    for i in range(0, height): #64
        for j in range(0, (width//8)+unalign): #128/8=16
            v = 0x00
            rs = 8*j      
            re = 8*(j+1)  
            if re > width:
                re = width
            for k in range(rs, re):
                if frame[i, k] != 0:
                    if not byte_reverse:
                        v |= (0x01 << (k%8))
                    else:
                        v |= (0x01 << (7-(k%8)))
            if color_reverse:
                v ^= 0xff
            matrix.append(v)

    return matrix

2.3 開啟socket服務

def socket_start():
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    host = socket.gethostbyname(socket.gethostname())
    port = 8080

    host = '192.168.5.100'
    print(host)
    print(port)
    s.bind((host,port))
    s.listen(5)

    print('等待客戶端連接中…')

    client,client_address = s.accept()
    print('新連接')
    client_IP = str(client_address[0])
    print('IP:'+client_IP)
    client_port = str(client_address[1])
    print('Port:' + client_port)

    return client

3 測試效果

https://www.bilibili.com/video/BV11S4y1S7ir

4 總結

本篇介紹ESP8266在OLED上播放視頻，包括ESP8266端的圖像接收與顯示程序，與電腦端的Python讀取視頻并進行編碼與數(shù)據(jù)發(fā)送程序。