cmake: make video backend optional via VIDEO_BACKEND flag

Add VIDEO_BACKEND cmake option (default ON) that controls whether FFmpeg
is required and video playback is compiled in. When OFF, VideoBackend.cpp
is excluded from the build and all video code paths in Background are
gated by HYPRLOCK_HAS_VIDEO, allowing a no-FFmpeg build for packagers
who want to ship without the dependency.

CMakeLists.txt

@@ -88,11 +88,15 @@ pkg_check_modules(
   gbm
   hyprutils>=0.11.0
   sdbus-c++>=2.0.0
-  hyprgraphics>=0.1.6
-  libavcodec
-  libavformat
-  libavutil
-  libswscale)
+  hyprgraphics>=0.1.6)
+
+option(VIDEO_BACKEND "Enable video background support via FFmpeg" ON)
+if(VIDEO_BACKEND)
+  pkg_check_modules(ffmpeg REQUIRED IMPORTED_TARGET libavcodec libavformat libavutil libswscale)
+  message(STATUS "Video backend: enabled")
+else()
+  message(STATUS "Video backend: disabled")
+endif()
 find_library(PAM_FOUND NAMES pam libpam)
 if(PAM_FOUND)
   set(PAM_LIB ${PAM_FOUND})
@@ -108,10 +112,20 @@ endif()
 message(STATUS "Found pam at ${PAM_LIB}")
 
 file(GLOB_RECURSE SRCFILES CONFIGURE_DEPENDS "src/*.cpp")
+
+if(NOT VIDEO_BACKEND)
+  list(FILTER SRCFILES EXCLUDE REGEX ".*/VideoBackend\\.cpp$")
+endif()
+
 add_executable(hyprlock ${SRCFILES})
 target_link_libraries(hyprlock PRIVATE ${PAM_LIB} rt Threads::Threads PkgConfig::deps
                                        OpenGL::EGL OpenGL::GLES3)
 
+if(VIDEO_BACKEND)
+  target_compile_definitions(hyprlock PRIVATE HYPRLOCK_HAS_VIDEO)
+  target_link_libraries(hyprlock PRIVATE PkgConfig::ffmpeg)
+endif()
+
 # protocols
 pkg_get_variable(WAYLAND_PROTOCOLS_DIR wayland-protocols pkgdatadir)
 message(STATUS "Found wayland-protocols at ${WAYLAND_PROTOCOLS_DIR}")

src/renderer/widgets/Background.cpp

@@ -87,6 +87,7 @@ void CBackground::configure(const std::unordered_map<std::string, std::any>& pro
             resourceID = 0;
         }
     } else if (!path.empty()) {
+#ifdef HYPRLOCK_HAS_VIDEO
         if (CVideoBackend::isVideoFile(path)) {
             m_videoBackend = makeUnique<CVideoBackend>();
             if (!m_videoBackend->open(path)) {
@@ -96,12 +97,18 @@ void CBackground::configure(const std::unordered_map<std::string, std::any>& pro
             } else {
                 m_uploadBuffer.resize(4 * m_videoBackend->frameW() * m_videoBackend->frameH());
             }
-        } else {
+        } else
+#endif
+        {
             resourceID = g_asyncResourceManager->requestImage(path, m_imageRevision, nullptr);
         }
     }
 
-    if (!reloadCommand.empty() && reloadTime > -1 && !m_videoBackend) {
+    if (!reloadCommand.empty() && reloadTime > -1
+#ifdef HYPRLOCK_HAS_VIDEO
+        && !m_videoBackend
+#endif
+    ) {
         try {
             if (!isScreenshot)
                 modificationTime = std::filesystem::last_write_time(absolutePath(path, ""));
@@ -112,11 +119,13 @@ void CBackground::configure(const std::unordered_map<std::string, std::any>& pro
 }
 
 void CBackground::reset() {
+#ifdef HYPRLOCK_HAS_VIDEO
     if (m_videoBackend) {
         m_videoBackend.reset();
         m_videoTexture.destroyTexture();
         m_uploadBuffer.clear();
     }
+#endif
 
     if (reloadTimer) {
         reloadTimer->cancel();
@@ -243,6 +252,7 @@ void CBackground::renderToFB(const CTexture& tex, CFramebuffer& fb, int passes,
 }
 
 bool CBackground::draw(const SRenderData& data) {
+#ifdef HYPRLOCK_HAS_VIDEO
     // ── Video background fast path ────────────────────────────────────────
     if (m_videoBackend) {
         if (m_videoBackend->swapFrame(m_uploadBuffer)) {
@@ -286,6 +296,7 @@ bool CBackground::draw(const SRenderData& data) {
         return true; // always request the next compositor frame
     }
     // ── End video path ────────────────────────────────────────────────────
+#endif
 
     updatePrimaryAsset();
     updatePendingAsset();

src/renderer/widgets/Background.hpp

@@ -6,7 +6,9 @@
 #include "../../helpers/Color.hpp"
 #include "../../core/Timer.hpp"
 #include "../Framebuffer.hpp"
+#ifdef HYPRLOCK_HAS_VIDEO
 #include "../VideoBackend.hpp"
+#endif
 #include <hyprutils/math/Misc.hpp>
 #include <string>
 #include <unordered_map>
@@ -86,7 +88,9 @@ class CBackground : public IWidget {
     size_t                          m_imageRevision = 0;
 
     // Video playback
+#ifdef HYPRLOCK_HAS_VIDEO
     UP<CVideoBackend>       m_videoBackend;
     CTexture                m_videoTexture;
     std::vector<uint8_t>    m_uploadBuffer;
+#endif
 };