screencopy: fixup timing issues with frame re-scheduling

ref #120

src/core/PortalManager.cpp

@@ -41,7 +41,8 @@ static void handleOutputDone(void* data, struct wl_output* wl_output) {
 }
 
 static void handleOutputMode(void* data, struct wl_output* wl_output, uint32_t flags, int32_t width, int32_t height, int32_t refresh) {
-    ;
+    const auto POUTPUT = (SOutput*)data;
+    POUTPUT->refreshRate = std::round(refresh / 1000.0);
 }
 
 static void handleOutputScale(void* data, struct wl_output* wl_output, int32_t factor) {
@@ -422,7 +423,7 @@ void CPortalManager::startEventLoop() {
         // wait for being awakened
         std::unique_lock lk(m_sEventLoopInternals.loopMutex);
         if (m_sEventLoopInternals.shouldProcess == false) // avoid a lock if a thread managed to request something already since we .unlock()ed
-            m_sEventLoopInternals.loopSignal.wait(lk, [this] { return m_sEventLoopInternals.shouldProcess == true; }); // wait for events
+            m_sEventLoopInternals.loopSignal.wait_for(lk, std::chrono::seconds(5), [this] { return m_sEventLoopInternals.shouldProcess == true; }); // wait for events
 
         std::lock_guard<std::mutex> lg(m_sEventLoopInternals.loopRequestMutex);
 
@@ -464,7 +465,6 @@ void CPortalManager::startEventLoop() {
             }
         }
 
-        // finalize wayland dispatching. Dispatch pending on the queue
         int ret = 0;
         do {
             ret = wl_display_dispatch_pending(m_sWaylandConnection.display);

src/core/PortalManager.hpp

@@ -21,6 +21,7 @@ struct SOutput {
     std::string         name;
     wl_output*          output      = nullptr;
     uint32_t            id          = 0;
+    float               refreshRate = 60.0;
     wl_output_transform transform   = WL_OUTPUT_TRANSFORM_NORMAL;
 };
 

src/portals/Screencopy.cpp

@@ -488,6 +488,11 @@ void CScreencopyPortal::onSelectSources(sdbus::MethodCall& call) {
     if (SHAREDATA.type == TYPE_WINDOW && !m_sState.toplevel) {
         Debug::log(ERR, "[screencopy] Requested type window for no toplevel export protocol!");
         SHAREDATA.type = TYPE_INVALID;
+    } else if (SHAREDATA.type == TYPE_OUTPUT || SHAREDATA.type == TYPE_GEOMETRY) {
+        const auto POUTPUT = g_pPortalManager->getOutputFromName(SHAREDATA.output);
+
+        if (POUTPUT)
+            PSESSION->sharingData.framerate = POUTPUT->refreshRate;
     }
 
     PSESSION->selection = SHAREDATA;
@@ -670,7 +675,15 @@ void CScreencopyPortal::queueNextShareFrame(CScreencopyPortal::SSession* pSessio
     if (PSTREAM && !PSTREAM->streamState)
         return;
 
-    g_pPortalManager->addTimer({1000.0 / pSession->sharingData.framerate, [pSession]() { g_pPortalManager->m_sPortals.screencopy->startFrameCopy(pSession); }});
+    // calculate frame delta and queue next frame
+    const auto FRAMETOOKMS           = std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::system_clock::now() - pSession->sharingData.begunFrame).count() / 1000.0;
+    const auto MSTILNEXTREFRESH      = 1000.0 / (pSession->sharingData.framerate) - FRAMETOOKMS;
+    pSession->sharingData.begunFrame = std::chrono::system_clock::now();
+
+    Debug::log(TRACE, "[screencopy] set fps {}, ms till next refresh {:.2f}, estimated actual fps: {:.2f}", pSession->sharingData.framerate, MSTILNEXTREFRESH,
+               std::clamp(1000.0 / FRAMETOOKMS, 1.0, (double)pSession->sharingData.framerate));
+
+    g_pPortalManager->addTimer({std::clamp(MSTILNEXTREFRESH, 1.0, 1000.0), [pSession]() { g_pPortalManager->m_sPortals.screencopy->startFrameCopy(pSession); }});
 }
 bool CScreencopyPortal::hasToplevelCapabilities() {
     return m_sState.toplevel;
@@ -804,6 +817,7 @@ static void pwStreamParamChanged(void* data, uint32_t id, const spa_pod* param)
     spa_pod_dynamic_builder_init(&dynBuilder[2], params_buffer[2], sizeof(params_buffer[2]), 2048);
 
     spa_format_video_raw_parse(param, &PSTREAM->pwVideoInfo);
+    Debug::log(TRACE, "[pw] Framerate: {}/{}", PSTREAM->pwVideoInfo.max_framerate.num, PSTREAM->pwVideoInfo.max_framerate.denom);
     PSTREAM->pSession->sharingData.framerate = PSTREAM->pwVideoInfo.max_framerate.num / PSTREAM->pwVideoInfo.max_framerate.denom;
 
     uint32_t                   data_type = 1 << SPA_DATA_MemFd;

src/portals/Screencopy.hpp

@@ -6,6 +6,7 @@
 #include "../shared/ScreencopyShared.hpp"
 #include <gbm.h>
 #include "../shared/Session.hpp"
+#include <chrono>
 
 enum cursorModes {
     HIDDEN   = 1,
@@ -79,6 +80,7 @@ class CScreencopyPortal {
             uint32_t                              nodeID              = 0;
             uint32_t                              framerate           = 60;
             wl_output_transform                   transform           = WL_OUTPUT_TRANSFORM_NORMAL;
+            std::chrono::system_clock::time_point begunFrame          = std::chrono::system_clock::now();
 
             struct {
                 uint32_t w = 0, h = 0, size = 0, stride = 0, fmt = 0;