完成同步播放

receiver.cpp

@@ -3,6 +3,7 @@
 #include <zmq.hpp>
 #include <chrono>
 #include <thread>
+#include <sys/time.h>
 
 int main() {
     // 创建ZeroMQ上下文
@@ -21,6 +22,11 @@ int main() {
     double avgFps = 0.0;
     double avgInterval = 0.0;
     std::chrono::steady_clock::time_point startTime = std::chrono::steady_clock::now();
+    struct timeval tv1, tv2;
+    gettimeofday(&tv1, NULL);
+    int lastFrameCount = 0;
+    double lastTotalTime = 0.0;
+    float tspan = 0.0;
 
     // 接收并实时播放视频帧
     while (true) {
@@ -44,53 +50,69 @@ int main() {
         double fps;
         memcpy(&fps, static_cast<char*>(message.data()) + sizeof(int) * 3 + imageDataSize, sizeof(double));
 
-        // 显示图像
-        cv::imshow("Received Video", frame);
+        // 为了保证周期的准确，一下代码应该写到一起，关键点在于：算当前时间、等待剩余时间、重置时间三者的关系必须是依次紧挨这，中间不要加入额外操作，重置时间以后可以加入其他操作，不用着急imshow
+        {
+            // 获取当前时间点
+            std::chrono::steady_clock::time_point currentTime = std::chrono::steady_clock::now();
 
-        // 获取当前时间点
-        std::chrono::steady_clock::time_point currentTime = std::chrono::steady_clock::now();
+            // 计算已经过去的时间
+            std::chrono::duration<double> elapsedSeconds = currentTime - startTime;
 
-        // 计算已经过去的时间
-        std::chrono::duration<double> elapsedSeconds = currentTime - startTime;
+            // 计算应该等待的时间间隔
+            double expectedInterval = 1000 / fps;
 
-        // 计算应该等待的时间间隔
-        double expectedInterval = 1000 / fps;
+            // 计算实际需要等待的时间间隔
+            double actualInterval = expectedInterval - elapsedSeconds.count() * 1000;
 
-        // 计算实际需要等待的时间间隔
-        double actualInterval = expectedInterval - elapsedSeconds.count() * 1000;
+            // 等待剩余时间，以实现与原视频完全一致的帧率
+            if (actualInterval > 0) {
+                std::this_thread::sleep_for(std::chrono::milliseconds(static_cast<int>(std::round(actualInterval))));
+            } else {
+                printf("Error! Accept and process the image timeout, if it is the first frame please ignore!\n");
+            }
 
-        // 更新统计变量
-        frameCount++;
-        totalTime += elapsedSeconds.count();
+            // 更新起始时间点和计时器
+            startTime = std::chrono::steady_clock::now();
 
-        // 每秒钟打印一次统计结果
-        if (totalTime >= 1.0) {
-            avgFps = frameCount / totalTime;
-            avgInterval = 1000 / avgFps;
-            std::cout << "Average FPS (last 1 second): " << avgFps << std::endl;
-            std::cout << "Average Interval (last 1 second): " << avgInterval << " ms" << std::endl;
-
-            // 重置统计变量
-            frameCount = 0;
-            totalTime = 0.0;
+            // 打印帧率和时间间隔信息
+            // std::cout << "Received FPS: " << fps << std::endl;
+            // std::cout << "Expected Interval: " << expectedInterval << " ms" << std::endl;
+            // std::cout << "Elapsed Seconds: " << elapsedSeconds.count() * 1000 << " ms" << std::endl;
+            // std::cout << "Actual Interval: " << actualInterval << " ms" << std::endl;
+        }
+      
+        // 调试，在imshow前引入time.h的时间来统计帧率，看是否已经实时播放
+        {
+            gettimeofday(&tv2, NULL);
+            tspan = (tv2.tv_sec - tv1.tv_sec) * 1000.0 + (tv2.tv_usec - tv1.tv_usec) / 1000.0;
+            //printf("****************************the tspan=%f ms****************************\n", tspan);
+            gettimeofday(&tv1, NULL);
         }
 
+        // 显示图像
+        cv::imshow("Received Video", frame);
+
         // 按下 ESC 键退出循环
         if (cv::waitKey(1) == 27)
             break;
 
-        // 打印帧率和时间间隔信息
-        std::cout << "Received FPS: " << fps << std::endl;
-        std::cout << "Expected Interval: " << expectedInterval << " ms" << std::endl;
-        std::cout << "Elapsed Seconds: " << elapsedSeconds.count() << " s" << std::endl;
-        std::cout << "Actual Interval: " << actualInterval << " ms" << std::endl;
+        // 更新统计变量
+        frameCount++;
+        totalTime += tspan/1000;
 
-        // 等待剩余时间，以实现与原视频完全一致的帧率
-        if (actualInterval > 0)
-            std::this_thread::sleep_for(std::chrono::milliseconds(static_cast<int>(std::round(actualInterval))));
+        // 每秒钟打印一次统计结果
+        if (totalTime - lastTotalTime >= 1.0) {
+            int currentFrameCount = frameCount - lastFrameCount;
+            double currentTotalTime = totalTime - lastTotalTime;
+            avgFps = currentFrameCount / currentTotalTime;
+            avgInterval = currentTotalTime * 1000 / currentFrameCount;
+            std::cout << "Average FPS (last 1 second): " << avgFps << std::endl;
+            std::cout << "Average Interval (last 1 second): " << avgInterval << " ms" << std::endl;
 
-        // 更新起始时间点
-        startTime = currentTime;
+            // 更新上次统计的帧数和时间
+            lastFrameCount = frameCount;
+            lastTotalTime = totalTime;
+        }  
     }
 
     // 关闭套接字