fix: attempt to fix background and resume issues with pip and new renderer changes

VoidLink/Stream/VideoDecoderRenderer.h

@@ -30,6 +30,7 @@
 - (void)safeCopyMetricsTo:(PlotMetrics *)dst from:(PlotMetrics *)src;
 - (void)getAllStats:(video_stats_t *)stats;
 - (void)optimizeRefreshRate;
+- (void)resetFramePacing;
 
 - (int)submitDecodeBuffer:(unsigned char *)data
                    length:(int)length

VoidLink/Stream/VideoDecoderRenderer.m

@@ -98,6 +98,8 @@ extern int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size,
     }
     
     if (_decompressionSession != nil){
+        VTDecompressionSessionWaitForAsynchronousFrames(_decompressionSession);
+        
         VTDecompressionSessionInvalidate(_decompressionSession);
         CFRelease(_decompressionSession);
         _decompressionSession = nil;
@@ -1129,4 +1131,26 @@ int DrSubmitDecodeUnit(PDECODE_UNIT decodeUnit);
     }
 }
 
+- (void)resetFramePacing {
+    // Ensure this only runs for the AVSampleBuffer rendering backend and that the display link exists.
+    if (_renderingBackend == RENDER_AVSB && _displayLink) {
+        Log(LOG_I, @"Frame pacing is being reset to %d FPS...", self->_frameRate);
+
+        // Toggling the paused state can help re-engage the display link with the
+        // run loop correctly after the app resumes from a background state like PiP.
+        _displayLink.paused = YES;
+
+        // Re-apply the desired frame rate range. This is the critical hint for ProMotion
+        // that may have been lost or ignored during the PiP transition.
+        if (@available(iOS 15.0, *)) {
+            _displayLink.preferredFrameRateRange = CAFrameRateRangeMake(self->_frameRate, self->_frameRate, self->_frameRate);
+        } else {
+            _displayLink.preferredFramesPerSecond = self->_frameRate;
+        }
+
+        // Resume the display link immediately.
+        _displayLink.paused = NO;
+    }
+}
+
 @end

VoidLink/ViewControllers/StreamFrameViewController.m

@@ -95,6 +95,10 @@
 
 - (void)pictureInPictureControllerWillStartPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
     _streamView.hidden = YES;
+    if (self.imguiView) {
+        self.imguiView.mtkView.hidden = YES;
+        Log(LOG_I, @"Hiding ImGui view for PiP start.");
+    }
 }
 
 - (void)pictureInPictureControllerDidStartPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
@@ -110,15 +114,23 @@
 
 - (void)pictureInPictureControllerDidStopPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {
     _streamView.hidden = NO;
+    if (self.imguiView) {
+        self.imguiView.mtkView.hidden = NO;
+        Log(LOG_I, @"Showing ImGui view after PiP stop.");
+    }
+    
     if (!_isRestoringFromPiP) {
         [self returnToMainFrame];
     }
-    _isRestoringFromPiP = NO;
 }
 
 - (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController restoreUserInterfaceForPictureInPictureStopWithCompletionHandler:(void (^)(BOOL restored))completionHandler {
     _isRestoringFromPiP = YES;
     _streamView.hidden = NO;
+    if (self.imguiView) {
+        self.imguiView.mtkView.hidden = NO;
+        Log(LOG_I, @"Showing ImGui view for PiP restore.");
+    }
     completionHandler(YES);
 }
 
@@ -343,6 +355,13 @@
                                                              userInfo:nil
                                                               repeats:_settings.statsOverlayEnabled];
     
+    if (self.metalViewController && self.metalViewController.view.superview) {
+        [self.view bringSubviewToFront:self.metalViewController.view];
+    }
+    if (self.imguiView && self.imguiView.mtkView.superview) {
+        [self.view bringSubviewToFront:self.imguiView.mtkView];
+    }
+    
     NSLog(@"frameview gestures: %d", (uint32_t)[self.view.gestureRecognizers count]);
     NSLog(@"streamview gestures: %d", (uint32_t)[_streamView.gestureRecognizers count]);
 }
@@ -909,19 +928,23 @@
 }
 
 - (void)applicationDidBecomeActive:(NSNotification *)notification {
-    // Stop the background timer, since we're foregrounded again
+    // Stop the background timer
     if (_inactivityTimer != nil) {
         Log(LOG_I, @"Stopping inactivity timer after becoming active again");
         [_inactivityTimer invalidate];
         _inactivityTimer = nil;
     }
+    
+    // Check if we were in PiP
     if (self.pipController && self.pipController.isPictureInPictureActive) {
         [self.pipController stopPictureInPicture];
     }
     
-    //self.pipController = nil;
-    //[self setupPiPControllerWithRenderer:self->_streamMan.videoRenderer];
-    //self->_streamMan.videoRenderer.
+    if (_isRestoringFromPiP) {
+        [self->_streamMan.videoRenderer resetFramePacing];
+    }
+    
+    _isRestoringFromPiP = NO;
 }
 
 // This fires when the home button is pressed
@@ -1365,6 +1388,11 @@
 - (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
     [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
     
+    if (_isRestoringFromPiP) {
+        Log(LOG_I, @"View size changed during PiP restore, skipping redundant reconfiguration.");
+        return;
+    }
+    
     Log(LOG_I, @"View size changed, terminating stream");
     
     double delayInSeconds = 0.2;