dxgiscreencapsrc: renegotiate caps on resolution change

When desktop gets resized, recreate the textures and renegotiate the
source caps with the updated video dimensions.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2249>

sys/winscreencap/dxgicapture.c

@@ -206,11 +206,12 @@ gst_dxgicap_shader_init (void)
   return ! !GstD3DCompileFunc;
 }
 
-static gboolean
+static GstFlowReturn
 initialize_output_duplication (DxgiCapture * self)
 {
   HDESK hdesk;
   HRESULT hr;
+  DXGI_OUTDUPL_DESC old_dupl_desc;
   GstDXGIScreenCapSrc *src = self->src;
 
   PTR_RELEASE (self->dxgi_dupl);
@@ -235,10 +236,29 @@ initialize_output_duplication (DxgiCapture * self)
     GST_WARNING_OBJECT (src, "IDXGIOutput1::DuplicateOutput() failed (%x): %s",
         (guint) hr, msg);
     g_free (msg);
-    return FALSE;
+    if (hr == E_ACCESSDENIED) {
+      /* Happens temporarily during resolution changes. */
+      return GST_FLOW_OK;
+    }
+    return GST_FLOW_ERROR;
   }
 
-  return TRUE;
+  old_dupl_desc = self->dupl_desc;
+  IDXGIOutputDuplication_GetDesc (self->dxgi_dupl, &self->dupl_desc);
+
+  if (self->readable_texture &&
+      (self->dupl_desc.ModeDesc.Width != old_dupl_desc.ModeDesc.Width ||
+          self->dupl_desc.ModeDesc.Height != old_dupl_desc.ModeDesc.Height ||
+          self->dupl_desc.Rotation != old_dupl_desc.Rotation)) {
+    PTR_RELEASE (self->readable_texture);
+    PTR_RELEASE (self->work_texture);
+
+    _setup_texture (self);
+
+    return GST_DXGICAP_FLOW_RESOLUTION_CHANGE;
+  }
+
+  return GST_FLOW_OK;
 }
 
 DxgiCapture *
@@ -314,11 +334,10 @@ dxgicap_new (HMONITOR monitor, GstDXGIScreenCapSrc * src)
 
   PTR_RELEASE (dxgi_factory1);
 
-  if (!initialize_output_duplication (self)) {
+  if (initialize_output_duplication (self) == GST_FLOW_ERROR) {
     goto new_error;
   }
 
-  IDXGIOutputDuplication_GetDesc (self->dxgi_dupl, &self->dupl_desc);
   self->pointer_buffer_capacity = INITIAL_POINTER_BUFFER_CAPACITY;
   self->pointer_buffer = g_malloc (self->pointer_buffer_capacity);
   if (NULL == self->pointer_buffer) {
@@ -451,11 +470,11 @@ dxgicap_stop (DxgiCapture * self)
   PTR_RELEASE (self->work_texture);
 }
 
-gboolean
+GstFlowReturn
 dxgicap_acquire_next_frame (DxgiCapture * self, gboolean show_cursor,
     guint timeout)
 {
-  gboolean ret = FALSE;
+  GstFlowReturn ret = GST_FLOW_ERROR;
   HRESULT hr;
   GstDXGIScreenCapSrc *src = self->src;
 
@@ -465,11 +484,9 @@ dxgicap_acquire_next_frame (DxgiCapture * self, gboolean show_cursor,
   if (!self->dxgi_dupl) {
     /* Desktop duplication interface became invalid due to desktop switch,
      * UAC prompt popping up, or similar event. Try to reinitialize. */
-    if (!initialize_output_duplication (self)) {
+    ret = initialize_output_duplication (self);
-      ret = TRUE;
     goto end;
   }
-  }
 
   /* Get the latest desktop frames. */
   hr = IDXGIOutputDuplication_AcquireNextFrame (self->dxgi_dupl,
@@ -478,13 +495,13 @@ dxgicap_acquire_next_frame (DxgiCapture * self, gboolean show_cursor,
     /* In case of DXGI_ERROR_WAIT_TIMEOUT,
      * it has not changed from the last time. */
     GST_LOG_OBJECT (src, "DXGI_ERROR_WAIT_TIMEOUT");
-    ret = TRUE;
+    ret = GST_FLOW_OK;
     goto end;
   } else if (hr == DXGI_ERROR_ACCESS_LOST) {
     GST_LOG_OBJECT (src, "DXGI_ERROR_ACCESS_LOST; reinitializing output "
         "duplication...");
     PTR_RELEASE (self->dxgi_dupl);
-    ret = TRUE;
+    ret = GST_FLOW_OK;
     goto end;
   }
   HR_FAILED_GOTO (hr, IDXGIOutputDuplication::AcquireNextFrame, end);
@@ -524,12 +541,12 @@ dxgicap_acquire_next_frame (DxgiCapture * self, gboolean show_cursor,
       }
       HR_FAILED_GOTO (hr, IDXGIOutputDuplication::GetFramePointerShape, end);
       self->pointer_shape_info = pointer_shape_info;
-      ret = TRUE;
+      ret = GST_FLOW_OK;
     } else {
-      ret = TRUE;
+      ret = GST_FLOW_OK;
     }
   } else {
-    ret = TRUE;
+    ret = GST_FLOW_OK;
   }
 end:
   if (self->dxgi_dupl) {

sys/winscreencap/dxgicapture.h

@@ -56,6 +56,7 @@
     } \
   } G_STMT_END
 
+#define GST_DXGICAP_FLOW_RESOLUTION_CHANGE GST_FLOW_CUSTOM_SUCCESS_1
 
 typedef struct _GstDXGIScreenCapSrc GstDXGIScreenCapSrc;
 
@@ -69,7 +70,7 @@ void dxgicap_destory (DxgiCapture * _this);
 gboolean dxgicap_start (DxgiCapture * _this);
 void dxgicap_stop (DxgiCapture * _this);
 
-gint dxgicap_acquire_next_frame (DxgiCapture * _this, gboolean show_cursor,
+GstFlowReturn dxgicap_acquire_next_frame (DxgiCapture * _this, gboolean show_cursor,
     guint timeout);
 gboolean dxgicap_copy_buffer (DxgiCapture * _this, gboolean show_cursor,
     LPRECT src_rect, GstVideoInfo * video_info, GstBuffer * buf);

sys/winscreencap/gstdxgiscreencapsrc.c

@@ -126,9 +126,8 @@ static gboolean gst_dxgi_screen_cap_src_stop (GstBaseSrc * bsrc);
 
 static gboolean gst_dxgi_screen_cap_src_unlock (GstBaseSrc * bsrc);
 
-static GstFlowReturn gst_dxgi_screen_cap_src_fill (GstPushSrc * pushsrc,
+static GstFlowReturn gst_dxgi_screen_cap_src_create (GstBaseSrc * pushsrc,
-    GstBuffer * buffer);
+    guint64 offset, guint length, GstBuffer ** buffer);
-
 
 static HMONITOR _get_hmonitor (GstDXGIScreenCapSrc * src);
 
@@ -139,12 +138,10 @@ gst_dxgi_screen_cap_src_class_init (GstDXGIScreenCapSrcClass * klass)
   GObjectClass *go_class;
   GstElementClass *e_class;
   GstBaseSrcClass *bs_class;
-  GstPushSrcClass *ps_class;
 
   go_class = G_OBJECT_CLASS (klass);
   e_class = GST_ELEMENT_CLASS (klass);
   bs_class = GST_BASE_SRC_CLASS (klass);
-  ps_class = GST_PUSH_SRC_CLASS (klass);
 
   go_class->set_property = gst_dxgi_screen_cap_src_set_property;
   go_class->get_property = gst_dxgi_screen_cap_src_get_property;
@@ -156,7 +153,7 @@ gst_dxgi_screen_cap_src_class_init (GstDXGIScreenCapSrcClass * klass)
   bs_class->stop = GST_DEBUG_FUNCPTR (gst_dxgi_screen_cap_src_stop);
   bs_class->unlock = GST_DEBUG_FUNCPTR (gst_dxgi_screen_cap_src_unlock);
   bs_class->fixate = GST_DEBUG_FUNCPTR (gst_dxgi_screen_cap_src_fixate);
-  ps_class->fill = GST_DEBUG_FUNCPTR (gst_dxgi_screen_cap_src_fill);
+  bs_class->create = GST_DEBUG_FUNCPTR (gst_dxgi_screen_cap_src_create);
 
   g_object_class_install_property (go_class, PROP_MONITOR,
       g_param_spec_int ("monitor", "Monitor",
@@ -442,12 +439,15 @@ gst_dxgi_screen_cap_src_unlock (GstBaseSrc * bsrc)
 }
 
 static GstFlowReturn
-gst_dxgi_screen_cap_src_fill (GstPushSrc * push_src, GstBuffer * buf)
+gst_dxgi_screen_cap_src_create (GstBaseSrc * base_src, guint64 offset,
+    guint length, GstBuffer ** buf)
 {
-  GstDXGIScreenCapSrc *src = GST_DXGI_SCREEN_CAP_SRC (push_src);
+  GstDXGIScreenCapSrc *src = GST_DXGI_SCREEN_CAP_SRC (base_src);
   GstClock *clock;
   GstClockTime buf_time, buf_dur;
   guint64 frame_number;
+  GstFlowReturn ret;
+  GstBuffer *buffer = NULL;
 
   if (G_UNLIKELY (!src->dxgi_capture)) {
     GST_DEBUG_OBJECT (src, "format wasn't negotiated before create function");
@@ -534,15 +534,40 @@ gst_dxgi_screen_cap_src_fill (GstPushSrc * push_src, GstBuffer * buf)
   }
 
   /* Get the latest desktop frame. */
-  if (dxgicap_acquire_next_frame (src->dxgi_capture, src->show_cursor, 0)) {
+  do {
+    ret = dxgicap_acquire_next_frame (src->dxgi_capture, src->show_cursor, 0);
+    if (ret == GST_DXGICAP_FLOW_RESOLUTION_CHANGE) {
+      GST_DEBUG_OBJECT (src, "Resolution change detected.");
+
+      if (!gst_base_src_negotiate (GST_BASE_SRC (src))) {
+        return GST_FLOW_NOT_NEGOTIATED;
+      }
+    }
+  } while (ret == GST_DXGICAP_FLOW_RESOLUTION_CHANGE);
+
+  if (ret != GST_FLOW_OK) {
+    return ret;
+  }
+
+  ret =
+      GST_BASE_SRC_CLASS (g_type_class_peek_parent (parent_class))->alloc
+      (base_src, offset, length, &buffer);
+  if (ret != GST_FLOW_OK) {
+    return ret;
+  }
+
   /* Copy the latest desktop frame to the video frame. */
   if (dxgicap_copy_buffer (src->dxgi_capture, src->show_cursor,
-            &src->src_rect, &src->video_info, buf)) {
+          &src->src_rect, &src->video_info, buffer)) {
-      GST_BUFFER_TIMESTAMP (buf) = buf_time;
+    GST_BUFFER_TIMESTAMP (buffer) = buf_time;
-      GST_BUFFER_DURATION (buf) = buf_dur;
+    GST_BUFFER_DURATION (buffer) = buf_dur;
+    *buf = buffer;
+
     return GST_FLOW_OK;
   }
-  }
+
+  gst_clear_buffer (&buffer);
+
   return GST_FLOW_ERROR;
 }