[all] align the frame data to the page boundary

VERSION

@@ -1 +1 @@
-B1-92-g0d29527758+1
+B1-94-g17df1ebc6b+1

c-host/src/app.c

@@ -109,6 +109,7 @@ static int frameThread(void * opaque)
   bool         repeatFrame    = false;
   int          frameIndex     = 0;
   CaptureFrame frame          = { 0 };
+  const long   pageSize       = sysinfo_getPageSize();
 
   (void)frameIndex;
   (void)repeatFrame;
@@ -182,9 +183,12 @@ static int frameThread(void * opaque)
     fi->height  = frame.height;
     fi->stride  = frame.stride;
     fi->pitch   = frame.pitch;
+    fi->offset  = pageSize - sizeof(FrameBuffer);
     frameValid  = true;
 
-    FrameBuffer fb = (FrameBuffer)(fi + 1);
+    // put the framebuffer on the border of the next page
+    // this is to allow for aligned DMA transfers by the receiver
+    FrameBuffer fb = (FrameBuffer)(((uint8_t*)fi) + fi->offset);
     framebuffer_prepare(fb);
 
     /* we post and then get the frame, this is intentional! */

client/src/main.c

@@ -440,7 +440,7 @@ static int frameThread(void * unused)
       updatePositionInfo();
     }
 
-    FrameBuffer fb = (FrameBuffer)(frame + 1);
+    FrameBuffer fb = (FrameBuffer)(((uint8_t*)frame) + frame->offset);
     if (!state.lgr->on_frame_event(state.lgrData, lgrFormat, fb))
     {
       DEBUG_ERROR("renderer on frame event returned failure");

common/include/common/KVMFR.h

@@ -60,5 +60,6 @@ typedef struct KVMFRFrame
   uint32_t    height;      // the height
   uint32_t    stride;      // the row stride (zero if compressed data)
   uint32_t    pitch;       // the row pitch  (stride in bytes or the compressed frame size)
+  uint32_t    offset;      // offset from the start of this header to the FrameBuffer header
 }
 KVMFRFrame;

obs/lg.c

@@ -164,7 +164,7 @@ static void lgVideoTick(void * data, float seconds)
     }
   }
 
-  FrameBuffer fb = (FrameBuffer)(frame + 1);
+  FrameBuffer fb = (FrameBuffer)(((uint8_t*)frame) + frame->offset);
 
   uint8_t *texData;
   uint32_t linesize;