0003-samplebufferdisplay-lifetime-placement.patch

# Backports VideoLAN VLC commits da8b3130c0, af61becb6c, 82803f4e26,
# and 1729b74116 onto SwiftVLC's pinned c833c4be0 source.
# Adapted to c833's Control callback and the preceding SwiftVLC aspect patch.
diff --git a/modules/video_output/apple/VLCSampleBufferDisplay.m b/modules/video_output/apple/VLCSampleBufferDisplay.m
index 567a03a..2d90143 100644
--- a/modules/video_output/apple/VLCSampleBufferDisplay.m
+++ b/modules/video_output/apple/VLCSampleBufferDisplay.m
@@ -563,23 +563,20 @@ - (void)drawRect:(CGRect)dirtyRect {
 #pragma mark -
 
 @interface VLCSampleBufferDisplayView: VLCView <CALayerDelegate>
-@property (nonatomic, readonly) vout_display_t *vd;
-- (instancetype)initWithVoutDisplay:(vout_display_t *)vd;
 - (AVSampleBufferDisplayLayer *)displayLayer;
 @end
 
 @implementation VLCSampleBufferDisplayView
 
-- (instancetype)initWithVoutDisplay:(vout_display_t *)vd {
+- (instancetype)init {
     self = [super init];
     if (!self)
         return nil;
-    _vd = vd;
 #if TARGET_OS_OSX
-    self.autoresizingMask = NSViewWidthSizable | NSViewHeightSizable;
+    self.autoresizingMask = NSViewNotSizable;
     self.wantsLayer = YES;
 #else
-    self.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
+    self.autoresizingMask = UIViewAutoresizingNone;
 #endif
     return self;
 }
@@ -642,7 +639,6 @@ - (BOOL)acceptsFirstResponder
 @interface VLCSampleBufferDisplay: NSObject
 {
     @public
-    vout_display_place_t place;
     filter_t *converter;
 }
     @property (nonatomic, readonly, weak) VLCView *window;
@@ -658,6 +654,7 @@ @interface VLCSampleBufferDisplay: NSObject
     - (instancetype)init NS_UNAVAILABLE;
     + (instancetype)new NS_UNAVAILABLE;
     - (instancetype)initWithVoutDisplay:(vout_display_t *)vd;
+    - (void)placeVideo:(vout_display_place_t)newPlace;
 @end
 
 /* The sample-buffer layer fits its enqueued frames by gravity, not by the
@@ -671,29 +668,28 @@ static AVLayerVideoGravity VLCGravityForDisplayCfg(const vout_display_cfg_t *cfg
     return AVLayerVideoGravityResizeAspect;
 }
 
-@implementation VLCSampleBufferDisplay
-
 /* A forced display aspect (libvlc_video_set_aspect_ratio) reaches the vout as a
  * target place rectangle, but AVSampleBufferDisplayLayer still fits the natural
  * pixel shape. Scale the natural aspect-fit box into VLC's computed place box so
  * forced ratios visibly stretch while the default path remains identity. The
- * fill (cover) path keeps its identity transform and uses layer gravity. */
-- (void)applyAspectStretch
+ * fill (cover) path keeps its identity transform and uses layer gravity.
+ *
+ * Compute the transform on the vout thread. A vout_display_t must never be
+ * retained or dereferenced by the asynchronous main-queue presentation block. */
+static CGAffineTransform VLCAspectStretchForDisplay(const vout_display_t *vd)
 {
-    AVSampleBufferDisplayLayer *layer = self.displayLayer;
-    if (!layer)
-        return;
-    const vout_display_place_t *p = self.vd->place;
-    const video_format_t *source = self.vd->source;
-    const vout_display_cfg_t *cfg = self.vd->cfg;
+    const vout_display_place_t *p = vd->place;
+    const video_format_t *source = vd->source;
+    const vout_display_cfg_t *cfg = vd->cfg;
     CGAffineTransform t = CGAffineTransformIdentity;
     if (source && cfg && p->width > 0 && p->height > 0
-        && cfg->display.width > 0 && cfg->display.height > 0
         && source->i_visible_width > 0 && source->i_visible_height > 0
         && cfg->display.fitting != VLC_VIDEO_FIT_LARGER)
     {
-        const double displayW = (double)cfg->display.width;
-        const double displayH = (double)cfg->display.height;
+        /* The display view is placed in p, so calculate the natural aspect-fit
+         * box in that coordinate space before stretching it to the full box. */
+        const double displayW = (double)p->width;
+        const double displayH = (double)p->height;
         const double naturalAR =
             (double)source->i_visible_width / (double)source->i_visible_height;
         const double displayAR = displayW / displayH;
@@ -710,9 +706,11 @@ - (void)applyAspectStretch
             t = CGAffineTransformMakeScale((double)p->width / naturalW,
                                            (double)p->height / naturalH);
     }
-    layer.affineTransform = t;
+    return t;
 }
 
+@implementation VLCSampleBufferDisplay
+
 - (id<VLCPixelBufferRotationContext>)rotationContext
 {
     if (_rotationContext)
@@ -763,6 +761,23 @@ - (void)preparePictureInPicture {
     }
 }
 
+- (CGRect)frameForPlace:(const vout_display_place_t *)place
+{
+    VLCView *window = self.window;
+    CGRect frame = CGRectMake(place->x, place->y, place->width, place->height);
+#if TARGET_OS_OSX
+    frame = [window convertRectFromBacking:frame];
+    frame.origin.y = window.bounds.size.height - frame.origin.y - frame.size.height;
+#else
+    CGFloat scale = window.contentScaleFactor;
+    frame.origin.x /= scale;
+    frame.origin.y /= scale;
+    frame.size.width /= scale;
+    frame.size.height /= scale;
+#endif
+    return frame;
+}
+
 - (void)prepareDisplay {
     @synchronized(_displayLayer) {
         if (_displayLayer)
@@ -770,6 +785,9 @@ - (void)prepareDisplay {
     }
 
     VLCSampleBufferDisplay *sys = self;
+    vout_display_place_t place = *_vd->place;
+    AVLayerVideoGravity gravity = VLCGravityForDisplayCfg(_vd->cfg);
+    CGAffineTransform aspectStretch = VLCAspectStretchForDisplay(_vd);
     dispatch_async(dispatch_get_main_queue(), ^{
         if (sys.displayView)
             return;
@@ -778,27 +796,29 @@ - (void)prepareDisplay {
         VLCSampleBufferSubpictureView *spuView;
         VLCView *window = sys.window;
 
-        displayView =
-            [[VLCSampleBufferDisplayView alloc] initWithVoutDisplay:sys.vd];
+        displayView = [[VLCSampleBufferDisplayView alloc] init];
         spuView = [VLCSampleBufferSubpictureView new];
         [window addSubview:displayView];
         [window addSubview:spuView];
-        [displayView setFrame:[window bounds]];
+        displayView.frame = [sys frameForPlace:&place];
         [spuView setFrame:[window bounds]];
 
-        sys->place = *sys.vd->place;
-
         sys.displayView = displayView;
         sys.spuView = spuView;
         @synchronized(sys.displayLayer) {
             sys.displayLayer = displayView.displayLayer;
         }
-        sys.displayLayer.videoGravity = VLCGravityForDisplayCfg(sys.vd->cfg);
-        [sys applyAspectStretch];
+        sys.displayLayer.videoGravity = gravity;
+        sys.displayLayer.affineTransform = aspectStretch;
         [sys preparePictureInPicture];
     });
 }
 
+- (void)placeVideo:(vout_display_place_t)newPlace
+{
+    self.displayView.frame = [self frameForPlace:&newPlace];
+}
+
 - (void)close {
     VLCSampleBufferDisplay *sys = self;
     dispatch_async(dispatch_get_main_queue(), ^{
@@ -1109,12 +1129,15 @@ static int Control (vout_display_t *vd, int query)
         case VOUT_DISPLAY_CHANGE_SOURCE_CROP:
         case VOUT_DISPLAY_CHANGE_SOURCE_PLACE:
         {
+            vout_display_place_t newPlace = *vd->place;
             AVLayerVideoGravity gravity = VLCGravityForDisplayCfg(vd->cfg);
+            CGAffineTransform aspectStretch = VLCAspectStretchForDisplay(vd);
             dispatch_async(dispatch_get_main_queue(), ^{
+                [sys placeVideo:newPlace];
                 @synchronized(sys.displayLayer) {
                     sys.displayLayer.videoGravity = gravity;
+                    sys.displayLayer.affineTransform = aspectStretch;
                 }
-                [sys applyAspectStretch];
             });
             break;
         }