Prepare and cache desktop video codecs once at application startup

tools/chatgui/src/main.cpp

@@ -19,11 +19,13 @@
 #include <QVBoxLayout>
 #include "gui_language.h"
 #include "call_camera_capture.h"
+#include "call_video_engine.h"
 #include "single_instance.h"
 #include "config_parser.h"
 #include <cstdio>
 #include <cstring>
 #include <cerrno>
+#include <future>
 #ifdef _WIN32
 #include <QStandardPaths>
 #include <windows.h>
@@ -342,6 +344,14 @@ int main(int argc, char *argv[]) {
                  cfg.debugLevel(), cfg.debugCategories());
     instance.setWindow(&w);
     if (minimized) w.showMinimized(); else w.show();
+    // Пробы не используют камеры и сеть; будущие звонки берут общий кэш без повторной подготовки.
+    std::atomic<bool> prepareVideo{true};
+    std::future<void> videoPreparation;
+    try {
+        videoPreparation = std::async(std::launch::async, [&prepareVideo] { CallVideoEngine::capabilities(&prepareVideo); });
+    } catch (const std::exception& error) {
+        DEBUG_ERROR(DEBUG_CATEGORY_CALL, "video codec background preparation could not start: %s", error.what());
+    }
     DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "GUI startup: minimized_requested=%d minimized=%d activation_server=%s",
         minimized, w.isMinimized(), qPrintable(instance.serverName()));
 
@@ -352,6 +362,11 @@ int main(int argc, char *argv[]) {
 #endif
 
     int ret = app.exec();
+    prepareVideo = false;
+    if (videoPreparation.valid()) {
+        try { videoPreparation.get(); }
+        catch (const std::exception& error) { DEBUG_ERROR(DEBUG_CATEGORY_CALL, "video codec background preparation failed: %s", error.what()); }
+    }
     DEBUG_DEBUG(DEBUG_CATEGORY_GENERAL, "main: app.exec() returned %d", ret);
     return ret;
 }