[feat] add Linux screen capture fallback support for DRM and Wayland

src/screen_capturer/linux/screen_capturer_drm.h

@@ -0,0 +1,87 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2026-03-22
+ * Copyright (c) 2026 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _SCREEN_CAPTURER_DRM_H_
+#define _SCREEN_CAPTURER_DRM_H_
+
+#include <atomic>
+#include <cstdint>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include "screen_capturer.h"
+
+namespace crossdesk {
+
+class ScreenCapturerDrm : public ScreenCapturer {
+ public:
+  ScreenCapturerDrm();
+  ~ScreenCapturerDrm();
+
+ public:
+  int Init(const int fps, cb_desktop_data cb) override;
+  int Destroy() override;
+  int Start(bool show_cursor) override;
+  int Stop() override;
+
+  int Pause(int monitor_index) override;
+  int Resume(int monitor_index) override;
+
+  int SwitchTo(int monitor_index) override;
+  int ResetToInitialMonitor() override;
+
+  std::vector<DisplayInfo> GetDisplayInfoList() override;
+
+ private:
+  struct DrmDevice {
+    int fd = -1;
+    std::string path;
+  };
+
+  struct DrmOutput {
+    int device_index = -1;
+    uint32_t connector_id = 0;
+    uint32_t crtc_id = 0;
+    std::string name;
+    int left = 0;
+    int top = 0;
+    int width = 0;
+    int height = 0;
+  };
+
+ private:
+  bool DiscoverOutputs();
+  void CloseDevices();
+  void CaptureLoop();
+  bool CaptureOutputFrame(const DrmOutput& output, bool emit_callback = true);
+  bool MapFramebuffer(int fd, uint32_t handle, size_t map_size,
+                      uint8_t** mapped_ptr, size_t* mapped_size,
+                      int* prime_fd) const;
+  void UnmapFramebuffer(uint8_t* mapped_ptr, size_t mapped_size,
+                        int prime_fd) const;
+
+ private:
+  std::vector<DrmDevice> devices_;
+  std::vector<DrmOutput> outputs_;
+  std::vector<DisplayInfo> display_info_list_;
+  std::thread thread_;
+  std::atomic<bool> running_{false};
+  std::atomic<bool> paused_{false};
+  std::atomic<int> monitor_index_{0};
+  int initial_monitor_index_ = 0;
+  std::atomic<bool> show_cursor_{true};
+  int fps_ = 60;
+  cb_desktop_data callback_;
+  int consecutive_failures_ = 0;
+
+  std::vector<uint8_t> y_plane_;
+  std::vector<uint8_t> uv_plane_;
+};
+
+}  // namespace crossdesk
+
+#endif