Fix: eliminate extra screen restarts on connection init

Two changes to reduce unnecessary CScreenSpy restarts when connecting:

1. Client (ScreenManager.cpp): Initialize CScreenSpy with bitrate from
   the locally-saved quality profile, so CMD_QUALITY_LEVEL arriving from
   the server (same bitrate as default) hits SetBitRate(3000)==3000 and
   skips the restart instead of comparing against the hard-coded 0.
   Also fixes QualityLevel init to use the already-computed `quality`
   variable (which honours the QUALITY_DISABLED override when algo!=NUL)
   rather than re-reading the cfg key a second time.

2. Server (ScreenSpyDlg.cpp): Only send CMD_SCREEN_SIZE strategy=2 when
   the session is in QUALITY_ADAPTIVE mode and a cached maxWidth exists.
   Fixed quality levels already carry resolution via CMD_QUALITY_PROFILES,
   so unconditionally sending CMD_SCREEN_SIZE caused a second restart when
   the screen spy was still rebuilding from the first one.

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

client/ScreenManager.cpp

@@ -153,7 +153,7 @@ CScreenManager::CScreenManager(IOCPClient* ClientObject, int n, void* user, BOOL
     m_ScreenSettings.FullScreen = cfg.GetInt("settings", "FullScreen", priv);
     m_ScreenSettings.RemoteCursor = cfg.GetInt("settings", "RemoteCursor", 0);
     m_ScreenSettings.ScrollDetectInterval = cfg.GetInt("settings", "ScrollDetectInterval", 2);  // 默认每2帧
-    m_ScreenSettings.QualityLevel = cfg.GetInt("settings", "QualityLevel", quality);
+    m_ScreenSettings.QualityLevel = quality;
     m_ScreenSettings.CpuSpeedup = cfg.GetInt("settings", "CpuSpeedup", 0);
     m_ScreenSettings.AudioEnabled = cfg.GetInt("settings", "AudioEnabled", 0);  // 默认禁用音频
     m_ScreenSettings.EncodeLevel = cfg.GetInt("settings", "EncodeLevel", LEVEL_H264_SOFT);
@@ -556,6 +556,10 @@ void CScreenManager::InitScreenSpy()
         m_isGDI = TRUE;
         m_ScreenSpyObject = new CScreenSpy(32, algo, DXGI == USING_VIRTUAL, DEFAULT_GOP, all, m_ScreenSettings.EncodeLevel, rect, switchScreen, m_hTargetWnd, m_bDynamicForeground);
     }
+    // 用已保存的质量配置初始化码率，避免 CMD_QUALITY_LEVEL 到达时 0→3000 触发不必要重启
+    if (m_ScreenSpyObject && level >= 0 && level < QUALITY_COUNT) {
+        m_ScreenSpyObject->SetBitRate(m_QualityProfiles[level].bitRate);
+    }
 }
 
 BOOL IsRunningAsSystem()

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);

server/2015Remote/ScreenSpyDlg.cpp

@@ -856,11 +856,12 @@ BOOL CScreenSpyDlg::OnInitDialog()
         BYTE cmd[4] = { CMD_QUALITY_LEVEL, (BYTE)m_AdaptiveQuality.currentLevel, 0 };
         m_ContextObject->Send2Client(cmd, sizeof(cmd));
 
-        // 始终发送 CMD_SCREEN_SIZE，让客户端同步分辨率策略
+        // 仅在自适应模式且有缓存宽度时同步分辨率，固定等级分辨率由 profile 决定无需重发
-        // maxWidth=0 表示使用默认分辨率（1080p 限制）
+        if (m_Settings.QualityLevel == QUALITY_ADAPTIVE && m_AdaptiveQuality.currentMaxWidth > 0) {
-        BYTE sizeCmd[16] = { CMD_SCREEN_SIZE, 2 };  // strategy=2 表示自适应质量
+            BYTE sizeCmd[16] = { CMD_SCREEN_SIZE, 2 };  // strategy=2 = 自适应质量
-        memcpy(sizeCmd + 2, &m_AdaptiveQuality.currentMaxWidth, sizeof(int));
+            memcpy(sizeCmd + 2, &m_AdaptiveQuality.currentMaxWidth, sizeof(int));
-        m_ContextObject->Send2Client(sizeCmd, 10);
+            m_ContextObject->Send2Client(sizeCmd, 10);
+        }
     }
 
     SendNext();
@@ -1478,6 +1479,11 @@ VOID CScreenSpyDlg::DrawNextScreenDiff(bool keyFrame)
             if (!m_bHide) {
                 if (Decode((LPBYTE)NextScreenData, NextScreenLength)) {
                     bChange = TRUE;
+                    // 解码成功即代表 IDR 参考帧已建立（编码器首帧强制 IDR），解除门控。
+                    // 不依赖 IsAnyKeyframe：某些硬编输出格式或解码器首帧 EAGAIN 延迟会导致
+                    // 关键帧检测误判，进而让 m_bIsFirst 永久为 TRUE（"请等待"卡死）。
+                    if (m_bIsFirst)
+                        m_bIsFirst = FALSE;
                 }
             }
             // Broadcast video frame to web clients (only for Web session dialogs)